Maldives - Male' hulhule bridge feasibility report August 2011 - Final

Ove Arup & Partners Hong Kong Ltd

Level 5 Festival Walk

80 Tat Chee Avenue

Kowloon Tong

Kowloon

Hong Kong

www.arup.com

GADL International Ltd

Feasibility Study for Construction of a Bridge between Malé and Hulhumalé

Final Report

REP-217093-01

Issue | August 2011

This report takes into account the particular

instructions and requirements of our client.

It is not intended for and should not be relied

upon by any third party and no responsibility is

undertaken to any third party.

Job number 217093


Feasibility Study for Construction of a Bridge between Malé and

GADL International Ltd Feasibility Study for Construction of a Bridge between Malé and HulhumaléFinal Report

HULHUMALE BRIDGE FINAL REPORT.DOCX

Contents

Page

Executive Summary i

1 Introduction 1

2 Project Context 2

2.1 Malé 2

2.2 Hulhumalé 3

2.3 Ibrahim Nasir International Airport 5

2.4 Greater Malé 6

2.5 The Eye of Maldives 6

2.6 Funadhoo Island 7

2.7 Moon Bay Marina 7

2.8 Site Conditions 8

2.9 Key Issues 11

2.10 Key Stakeholders 14

3 Alignment Options 15

3.1 Alternatives Considered 15

3.2 Landing Points and Traffic Dispersal 16

3.3 Initial Sifting of Alignment Options 19

4 Airport Operational Issues 21

4.1 Airport Height Restrictions 21

4.2 Ground Transportation 22

4.3 Traffic Volume 24

4.4 Conflicts Between Road and Air Traffic 24

4.5 Airport Emergency Vessels 25

4.6 Conclusions 25

5 Navigation Issues 26

5.1 Marine Activity 26

5.2 Airdraft 29

5.3 Span and Marine Safety 30

5.4 Ship Impact 32

5.5 Conclusions 32

6 Environmental Issues 33

6.1 Introduction 33

6.2 Environmental Legislation, Guidelines, Policies and International Conventions 33



6.3 Baseline Conditions 36

6.4 Potential Impacts and Mitigation Measures 40

6.5 Influence of Climate Change 45

7 Bridge Structure Options 46

7.1 Functional Cross Section 46

7.2 Structural Options (Alignment Option A) 48

7.3 Floating Bridge Option (Alignment C) 52

7.4 Operation & Maintenance 53

7.5 Appearance of the Bridge Options 55

8 Construction Cost Estimates 56

8.1 Methodology 56

8.2 Fixed Bridge on Alignment A 56

8.3 Floating Bridge on Alignment C 56

8.4 Operation & Maintenance Costs 57

9 Potential Financing & Revenue Models 58

9.1 Alternatives for Financing the Bridge 58

9.2 Sources of Revenue 60

9.3 Tolls 61

9.4 Payment in Kind 62

9.5 Conclusions 63

10 Comparison of Options 64

11 Conclusions & Recommendations for Further Study 65

References

Appendices

Appendix A

Drawings

Appendix B

Artistic Images


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HULHUMALE BRIDGE FINAL REPORT.DOCX Page i

Executive Summary

Introduction

GADL International Limited has commissioned Ove Arup & Partners Hong Kong Ltd to carry out an initial feasibility study for the construction of a bridge between the Malé and Hulhumalé Islands.

This feasibility study was commissioned on the 31st May 2011. After an initial

desk study, a site visit was carried out from 14th June to 16

th June 2011. In

addition to inspection of the site and potential landing points, stakeholder consultation meetings were carried out. After completion of the site visit, this report has been prepared to present the findings of the initial feasibility study.

Alignment Options

Three different alignments have been studied and an initial sifting exercise was carried out to determine the suitability of each alignment for different bridge types.

Bridge Type Option A Option B Option C

Fixed Bridge � Considered further � Unsuitable ground conditions – high risk

� High cost and poor functionality

Floating Bridge � Wave conditions are too rough – high risk. � Considered further

Alignment A is particularly favourable in terms of traffic dispersal on Malé and should result in the least amount of congestion on the island. It is also favourable in terms of allowing a direct connection to a future link to Villingili Island as part of the long term goal of connecting the Greater Malé region.

Airport Operational Issues

To maintain safe operation of the airport there are restrictions on the height of construction of the bridge which are very influential to the structural options that can be considered for the bridge. In view of the deep water, fast currents and ocean swells that are found in the Gaadhoo Koa, one option that could be considered would be to construct a bridge from shore to shore without any intermediate supports in the channel. However, this would require very tall towers which would violate the height restrictions.


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In addition to these restrictions it is apparent that the construction of the bridge will have an influence on the airport landside transport infrastructure system. Although the airport masterplan already considers the scenario of the bridge being constructed there may need to be further coordination between the airport development and government plans for public transport and road infrastructure between Malé and Hulhumalé.

Navigation Issues

The Maldives is an archipelago and marine traffic is an important aspect of everyday life in the islands. Construction of a bridge across the Gaadhoo Koa will have a significant influence on how vessels navigate around Malé, especially the larger commercial vessels. However, due to the large number of entries into the atoll it has been confirmed by key stakeholders that there will be no adverse impact to marine operations if appropriate additional navigation aids are provided for shipping using alternate channels.

All bridge options will provide sufficient airdraft for resort speedboats, local ferries and the airport firefighting vessel to pass under the bridge.

Environmental Issues

Based on the available data it appears that the environmental impacts of the bridge can be managed and mitigated.

Climate Change Resilience

Hulhumalé was built with a formation level 0.5m higher than Malé in order to provide greater resilience to sea level rise. The bridge, which will promote the development of Hulhumalé, will therefore be of benefit to the climate change resilience of the nation.

The provision of a fixed link could also assist the nation in coping with some effects of sea level rise, specifically:

• Facilitating disaster relief efforts

• Aiding with population mobility in view of shifting land use patterns

Traffic Congestion

There is a concern that the construction of the bridge could increase traffic congestion on the islands. Ways in which congestion can be tackled could include:

• Promoting public transport (buses) on the bridge

• Selecting a landing point which provides good traffic dispersal in Malé

• Implementing traffic improvements to facilitate dispersal

• Restricting types of vehicle that are permitted to use the bridge

Employment in Ferry Sector

Although the construction of the bridge will bring economic benefits to the majority of the population there is a concern that it will cause job losses for those currently either directly or indirectly employed in ferry operations between Malé and Hulhulé/Hulhumalé.


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It is possible that bus operations on the bridge could provide appropriate reemployment and this could be promoted by

• Retraining schemes (e.g. bus drivers licence, mechanics training etc.)

• Trade-in scheme where the government could provide mini-buses in return for ferries.

• Direct intervention (employment quotas)

• Toll structure on the bridge which promotes the use of buses

There would be some costs associated with these schemes but these would be a small percentage in comparison to the overall project cost.

Bridge Structure Options

Three different options for the bridge structure have been illustrated in general arrangement drawings and artistic images, two different fixed bridge alternatives on alignment option A and a floating bridge on alignment option C.

Balanced cantilever bridge on Alignment A

Extradosed bridge on Alignment A

Floating bridge on Alignment C


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HULHUMALE BRIDGE FINAL REPORT.DOCX Page iv

Construction Cost Estimates

A top down estimate has been made based on historic construction costs of similar projects calibrated or adjusted for features unique to the project

There are no historic projects of a similar nature in the Maldives. Therefore historic construction costs for international projects need to be considered. The adjustments that need to be made for features unique to this project are:

• Construction in the Maldives where all materials need to be imported

• Construction in deep water with weak and uncertain ground

Although material costs are relatively high in the Maldives, labour costs are relatively low compared to the countries where suitable reference projects have been identified. This has been taken into account in the cost adjustment.

The estimated cost of construction of the bridge is USD 70 to USD 100 million.

Potential Financing & Revenue Models

Based on government policy and current procurement trends in the Maldives it is believed that an appropriate PPP structure is likely to be the best way of financing the project.

The project is unlikely to be financially viable based solely on direct user fees (tolls). Therefore alternative financing and revenue strategies are required. It is likely that a successful strategy will combine the following elements:

• Private partner builds the bridge and then maintains and operates it for a fixed concession period (25 to 30 years)

• Initial government capital contribution in the form of Viability Gap Funding

• Additional Payment in Kind based on development rights / land leases for commercial / high value residential property in Hulhumalé

• Toll revenue collected by the private partner but respecting a pre-agreed toll structure which promotes public transport on the bridge

It is worth noting that the economic benefits of a project such as this frequently exceed the financial revenue that can be generated. This is because there are either long term benefits which are beyond the time frame of a private investor or because there are benefits which are associated with the project but for which a direct user charge cannot be applied.

In this case, the quality of life benefits achieved by reducing urban congestion in Malé and the enhanced climate change resilience by promoting development on slightly higher ground are both significant benefits. Therefore the fact that the project is not considered financially viable based on direct user fees should not be taken to mean that the project is not worthwhile.

Conclusions & Recommendations for Further Study

All parties consulted were in favour of the construction of a fixed link to connect Malé and Hulhumalé.

Construction of a bridge is feasible although there exist a number of significant technical and financial challenges which must be overcome.


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This Feasibility Study was envisaged as an initial scoping study and was limited by the time as well as the information available. In view of the anticipated benefits of the project it is recommended that a Preliminary Design study is carried out with the following objectives:

• Gather additional data • Confirm technical details of the project • Assess the impacts of the project • Update cost estimates • Develop procurement model for the project addressing the financial

requirements

An approximate timeline for the project is given below. It would be possible to slightly reduce the overall procurement timeline for the Design and Build / PPP procurement route by integrating the scope of works of the Bid Process Management into the Preliminary Design since this would allow prequalification to start earlier.

In order to control costs at this early stage of project development it could be possible to subdivide the Preliminary Design into two stages with the aim to limit design and investigation costs in Stage 1:

• Stage 1 - Conceptual design of options, update of cost estimates and selection of preferred option

• Stage 2 – Preliminary design, assessment of impact, further update of cost estimates and development of procurement model


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1 Introduction

The Government of the Republic of Maldives is interested to link various islands in the Greater Malé region by construction of bridges.

GADL International Limited has commissioned Ove Arup & Partners Hong Kong Ltd to carry out an initial feasibility study for the construction of one such bridge between the capital Malé and Hulhumalé Islands. Hulumalé is connected to Hulhulé (the airport island) by road alongside of the reef.

Malé is the capital and most populous city in the Republic of Maldives. It is located at the southern edge of North Malé Atoll (Kaafu Atoll).

Ibrahim Nasir International Airport is the only gateway to Maldives and is located on the Hulhulé Island which is 1km away from the capital, Malé.

A commercial harbour is located on Malé Island and is the heart of all commercial activities in the country. Malé Island is heavily urbanized, with the built-up area taking up essentially its entire landmass. Almost one third of the nation's population lives in the capital city, and the current population of this island is over 100,000.

Currently the only mode of transportation between Malé and Hulhulé islands is by boat / ferry. A link between the two islands by a bridge will make transport between the islands easier for both public transportation and cargo movement.

This feasibility study was commissioned on the 31st May 2011. After an initial

desk study, a site visit was carried out from 14th June to 16

th June 2011. In

addition to inspection of the site and potential landing points, stakeholder consultation meetings were carried out with representatives of the following organisations:

• The President’s Office • Ministry of Housing and Environment • Maldives Ports Limited • Maldivian Coast Guard • Malé Water & Sewerage Company Pvt Ltd • Environmental Protection Agency • Housing Development Corporation • GMR Malé International Airport Pvt. Ltd

After completion of the site visit, this report has been prepared to present the findings of the initial feasibility study.


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2 Project Context

2.1 Malé

Malé Island is heavily urbanized, with the built-up area taking up essentially its

entire landmass. Slightly less than one third of the nation's population lives in the

capital city, and the population has increased from 20,000 people in 1987 to over

100,000 people today. Malé is the centre of all commerce, administration and

government institutions in the Maldives.

Figure 1 Aerial view of Malé Island (Source: Wikimedia Commons © Shahee Ilyas)

Since there is no surrounding countryside, all infrastructure has to be located in the city itself. Water is provided from desalinated ground water; the water works pumps brackish water from 50-60m deep wells in the city and desalinates that using reverse osmosis. Electric power is generated in the city using diesel generators. Sewage is pumped unprocessed into the sea. Solid waste is transported to nearby islands, where it is used to fill in lagoons.

Figure 2 Progress of land reclamation up to 1992 (Source: [7])


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Reclamation of the lagoon on Malé has added more than half again to the original land area of the island which now extends almost to the edge of the reef on all sides except for the protruding submarine outer edge of the reef in the south east corner of the island.

In February 2002 a reef slope collapse occurred on the north eastern corner of the island, a solid jetty was destroyed and blocks and debris of the jetty fell down the reef slope. An investigation was made of the engineering geology of the island which concluded that there could be further potential slope failures on the critical north eastern margin of the island.[11]

2.2 Hulhumalé

Reclamation of the 188 hectares of Hulhumalé began on October 16, 1997 on the Hulhulé-Farukolhufushi lagoon 1.3 km off the north east coast of Malé. Initial reclamation (or Phase I) consisting of 45% of land mass was carried out by the Ministry of Construction and Public Works (MCPW) costing USD 11 million. The project was then continued by a Belgian Joint Venture Company, International Port Engineering and Management (IPEM) and Dredging International (DI) costing an estimated USD 21 million. All the works involving reclamation and coastal structure development covered in Phase I was completed by June 2002.

Development of Hulhumalé is masterminded by the government owned Housing Development Corporation (HDC). Originally solely responsible for the development and management of Hulhumalé the corporation is now mandated to undertake government housing projects not only in Hulhumalé but elsewhere in the Maldives as well. Its mission now is to relieve the urban congestion in the Maldives by providing housing in a socially responsible and commercially viable manner.

HDC’s main focus currently remains in developing Hulhumalé into a unique island city in the North Malé Atoll, while creating opportunities for better homes, health, employment and education services in the Maldives. HDC has three roles in the development of Hulhumalé.

• Firstly, it acts as a master developer, delivering the vision, inspiration and imagination of the project in a manner that is feasible and commercially viable.

• Secondly, HDC is a builder, investing in the infrastructure necessary for quality living and business prosperity. These include the development of roads, landscaping, and ensuring that basic utilities as well as other essential services are available for investors and residents.

• Lastly, HDC acts as regulator, overseeing detailed planning, architectural guidelines and building regulations.

HDC deals with the lease and sale of land as well as developed property on Hulhumalé. The company focuses on three broad areas of real estate development: residential, commercial, and industrial.

Primary developments in terms of the required physical and social infrastructure and residential developments were completed in 2004 and the very first settlement of Hulhumalé began in the middle of 2004 with a resident population of just over 1000 people. The current population is approximately 20,000 people.


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The target completion date for the development is 2020 with a target population of 60,000. At that time the population density would be approximately half the current density of Malé Island.

Figure 3 Hulhumalé Master Plan (Source: HDC)

Development so far has primarily been residential in the north east corner of Hulhumalé including social housing. It is understood that some social housing leases are being sublet to residents from outlying islands thereby frustrating the aim of tackling growing urban congestion in Malé.

Construction of a bridge between Malé and Hulhumalé would be very beneficial to the further development of Hulhumalé and to achieving the objective of fostering balanced land use and a diverse range of developments. Commercial developers would potentially be more likely to invest if Malé was seen to be more directly within their catchment of potential customers. Malé residents might also be more likely to move to Hulhumalé if they could more easily commute to their current employment on Malé thus achieving the aim of reducing urban congestion.

Figure 4 Beachfront residential developments in Hulhumalé

Figure 5 Streetscape in Hulhumalé


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Hulhumalé clearly has great potential to improve the quality of life for the

population by providing a lower density of urban living in a well planned

development which effectively utilizes the land to maximize environmental and

economic efficiency in terms of living space, productivity and provision of

employment. However, it is currently underutilized and it may require better

connectivity to help it to fully realize that potential.

2.3 Ibrahim Nasir International Airport

Ibrahim Nasir International Airport (MLE) is the main international airport in the Maldives. Despite the upgrading of Gan and Hanimaadhoo Airports to international standards, Ibrahim Nasir International Airport is likely to remain the main gateway into the Maldives for tourists.

Figure 6 Approach to Runway 36 (Source: Wikimedia Commons © PalawanOz)

The airport completely dominates Hulhulé Island and has been constructed on reclamation in the lagoon of the island. The airport opened to the public in April 1966 and has been through a series of renovations and upgrades including several additional stages of reclamation to expand the land area of the airport. Figure 6 shows the situation in 2003 before more recent reclamation at the southern end of the island.

The Maldives Airports Company Ltd. (MACL) was formed in 1994 as a financially and administratively independent corporate entity to manage the airport. MACL is governed by a Board of Directors appointed by the President of the Maldives

On 15 July 2010, the airport was privatised and on 25th November 2010, MACL

officially handed over the aerodrome license of the airport to the newly formed GMR Malé International Airport Pvt. Ltd, a consortium between GMR Group and Malaysia Airports. The airport has been leased to the consortium for 25 years with the aim to develop MLE into a global standard airport by the year 2014. MACL

Tourism accounts for 28% of Maldivian GDP and more than 60% of foreign exchange receipts.


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will continue to be responsible for some airport functions including Air Traffic Control and Aviation Security Command.

The centrepiece of the development plans is a new International Passenger Terminal to be built on a reclaimed lagoon to the east of the runway. Other developments include extension of the runway to the north to establish a Runway End Safety Area (RESA) at the south end of the runway.

2.4 Greater Malé

Although the objective of this assignment is to study the feasibility of a bridge between Malé and Hulhumalé (via Hulhulé), we are aware that this is part of a larger long term desire to link together a series of islands in the Greater Malé region.

Figure 7 Greater Malé

As far as the current assignment goes, the main way in which we have considered this long term goal is in terms of the traffic connectivity. The physical geography of Greater Malé as well as the current road layout in Hulhulé and Malé lends itself to the eventual fixed link being a “backbone” running along the perimeter of the atoll as indicated in Figure 7.

2.5 The Eye of Maldives

One of the islands in the Greater Malé region is Gulhi Falhu which is currently being developed into the Eye of Maldives.

Global Projects Development Company (Pvt) Ltd has a concession agreement with the Government of the Republic of Maldives to reclaim and develop Gulhi Falhu lagoon. Reclamation of Phase I (10 hectares) was completed on 18 September 2010. Phase II (40 hectares) will commence in 2011.

The Eye of Maldives masterplan currently shows a fixed link between Gulhi Falhu and Villingili islands as indicated in Figure 8.


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Figure 8 Eye of Maldives (Source: Global Projects Development Company Pvt Ltd)

2.6 Funadhoo Island

Funadhoo Island is a fuel storage facility operated by the government and located between Malé and Hulhulé islands.

It is understood from discussions with the Technical Advisor to the Minister of Housing and Environment that this facility will be relocated. We have therefore assumed that it would be possible for the road to pass over this island and indeed there could be some benefit to linking to this island to facilitate redevelopment since it is close to Malé.

Figure 9 Funadhoo Island (Source: Google)

The island includes an area of shallow water to the south east where breaking waves are observed.

2.7 Moon Bay Marina

We are aware of the Moon Bay Marina project from the promotional video which was widely circulated on the internet in early 2009. If this project were to go ahead it would have a significant impact on planning of the bridge. However, it is our understanding that this project will not be progressed and we have therefore excluded it from our consideration in preparing this report.


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2.8 Site Conditions

2.8.1 Topography

The islands are flat and are typically around 1.5m to 2.0m above mean sea level.

2.8.2 Bathymetry

Bathymetric data has been obtained from four sources:

• Admiralty Chart [1]

• University of South Florida (USF) bathymetry survey [12]

• Extract from recent Indian Survey data provided by Maldivian Coast Guard

• Extracts from bathymetric survey of Hulhulé Island [4]

There are some contradictions in the bathymetric data but it is clear that the water depth in the channel exceeds 50m and that the reef slopes are generally relatively steep. The data also appears to consistently indicate that the water is slightly shallower in the southern part of the channel and that the reef slope of the south east tip of Malé Island is somewhat gentler.

The USF data is the most detailed and the most recent so we have based our study on this. For the further development of the project it would be necessary to validate the USF data and obtain a digitised version.

Figure 10 Extract from USF bathymetry data [12]

Shallower

plateau area

Gentler reef

slope


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2.8.3 Metocean conditions

Metocean conditions are expected to be characterised by a moderate tidal range,

strong currents, moderate to rough ocean swells and steady winds. The conditions

are affected by the monsoons. Each year there are two monsoons seasons, the

north-east monsoon, (Iruvai) from December to April and the south west monsoon,

(Hulhangu) from May to October.

Tide

Tidal levels have been determined from the Admiralty Chart [1]. The tidal range at Malé and nearby is about 0.7m at Spring tides and 0.3m for Neap tides. A mean sea level of +0.6mCD has been assumed for this current study.

Place Heights in metres above datum (mCD)

MHHW MLHW MHLW MLLW

Malé 0.9 0.8 0.5 0.3

Current

The Maldives are affected by both seasonal and tidal currents. [1] states that the Gaadhoo Koa “channel is affected by seasonal monsoons causing strong currents up to 6 knots across the mouth of the channel.” Tidal currents occur due to the diurnal filling and emptying of the lagoons through the limited passages in the barrier reef. The Maldivian Coast Guard informed us that the tidal current strength in the Gaadhoo Koa has increased due to the reclamations in the area.

Waves

The wave height varies seasonally with the monsoons and June to August during the south west monsoon has the most potential for large swells. During this period the predominant wave direction is from the south. Seas are generally moderate (around 2m wave height) but can be rough (2.5m to 4m wave height) at times.

During the site visit strong breaking waves were observed on the shorelines exposed to the ocean, specifically the east coast of Malé and the southern breakwater of Hulhulé Island where minor overtopping was also observed. It was noted that the wave strength tended to reduce inside the atoll but surf was also observed at Funadhoo Island despite being some way from the edge of the atoll.

Wind

Steady winds exist at the site with the average monthly wind speed being between 4m/s and 6m/s and with calms never exceeding more than 2% of a month. The prevailing winds which can become quite strong, are from the SW-W-WN during the south-west monsoon and N-NE-E during the north-east monsoon. In May to


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October wind gusts may reach between 35-45 knots. However, the Maldives are not prone to tropical cyclones as it is outside of the cyclone region.

2.8.4 Ground conditions

Archipelago geology

The Maldives Archipelago comprises two chains of coral reef islands located above the north-south trending submarine Laccadive-Maldives Ridge. The basement of this ridge formed millions of years ago as the result of hot-spot related volcanic activity, with subsequent subsidence and carbonate sedimentation resulting in a thick overlying limestone sequence. The islands themselves, which only began to form around 5,500 years ago, are composed of reef-derived carbonate sediment deposited by waves and currents along the rims of coral reef atolls, giving rise to sub-circular clusters of islands, each surrounding a lagoon. The geomorphology of the islands is constantly changing through action of wind and sea which leads to erosion and deposition of banks, beaches and cays.

Due to their mode of deposition and post-depositional processes, carbonate deposits, and particularly those associated with coral atolls typically exhibit highly variable characteristics, including zones of unconsolidated or poorly consolidated granular deposits, zones of cementation, coral cavities and dissolution voids.

Local geology

After collapse of a section of the north eastern reef slope of Malé in 2002, a study was made to characterize the engineering geology environment of the margins of Malé Island, especially the north-eastern slope where the documented upper slope failure occurred. The Phase 1 Assessment Report [11] has been made available to us.

Based on interpretation of a high resolution multi-beam bathymetry survey the report makes a number of conclusions which are of particular significance to the bridge feasibility:

• Several surfaces of rupture (head scarps) are observed corresponding to collapse along the north eastern section of Malé Island

• Blocks and debris are observed down slope of the collapses

• The sea floor between Malé and Hulhulé Islands shows karst like figures (sinkholes) on the underwater plateau. The sink holes form lineaments which are parallel to the general orientation of the NE shores of Malé Island.

Expected conditions

It is expected that the sea floor will comprise of carbonate deposits overlain in places by unconsolidated granular deposits (coral sand). Sink holes are expected in some locations.

Due to the high tidal currents in the channel it is anticipated that sand deposits will tend to accumulate in deeper areas such as the sinkholes and will not be present in shallower areas. This has been anecdotally confirmed during our discussions with the Maldivian Coast Guard who have made a number of dives to the sea floor and were able to describe the conditions.


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2.9 Key Issues

A number of key issues for the project have been identified:

2.9.1 Project Financing

There are clearly significant economic benefits that would be obtained from this project and there is great interest from the Government and stakeholders in seeing the bridge be built. However, the project would represent a significant capital expenditure and securing the financing of that initial project going ahead.

2.9.2 Cost & Practicality of Construction

Intimately related to project financing is the need to reduce costs to try to limit the initial capital requirements. This requires the bridge to be designwhilst at the same time achieving the project objecti

In this particular case an economic design needs to respect the construction in the remote location of the Maldives. This means considering the logistics of importation of materials and planning the extent to which precasting and prefabrication can benefit the project.

2.9.3 Deep Water

The Gaadhoo Koa channel is up to 60m deep and it is a thousand metres from shore to shore. Strong currents represents a challenging define the metocean conditions in the channel

Project Financing

Cost & Practicality of Construction

Deep Water

Weak Ground Conditions

Airport Height Restrictions

Feasibility Study for Construction of a Bridge between Malé and Hulh

Key Issues

A number of key issues for the project have been identified:

Project Financing

clearly significant economic benefits that would be obtained from this is great interest from the Government and stakeholders in seeing

the bridge be built. However, the project would represent a significant capital expenditure and securing the financing of that initial investment is critical to the

& Practicality of Construction

Intimately related to project financing is the need to reduce costs to try to limit the requirements. This requires the bridge to be designed economically

whilst at the same time achieving the project objectives.

In this particular case an economic design needs to respect the practicalityconstruction in the remote location of the Maldives. This means considering the logistics of importation of materials and planning the extent to which precasting

brication can benefit the project.

Deep Water

Koa channel is up to 60m deep and it is a thousand metres from Strong currents and ocean swells are present in the channel

environment for construction and more data is required to define the metocean conditions in the channel.

Project Financing

Cost & Practicality of Construction

Deep Water

Weak Ground Conditions

Airport Height Restrictions

Navigation

Operation & Maintenance

Traffic Congestion


Environmental Impact

Feasibility Study for Construction of a Bridge between Malé and HulhumaléFinal Report

Page 11

clearly significant economic benefits that would be obtained from this is great interest from the Government and stakeholders in seeing

the bridge be built. However, the project would represent a significant capital is critical to the

Intimately related to project financing is the need to reduce costs to try to limit the economically

practicality of construction in the remote location of the Maldives. This means considering the logistics of importation of materials and planning the extent to which precasting

Koa channel is up to 60m deep and it is a thousand metres from are present in the channel. This

and more data is required to

Navigation


Traffic Congestion


Environmental Impact


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2.9.4 Weak and Uncertain Ground Conditions

There is no ground investigation data available for the site. However, the local geological conditions indicate the ground is likely to be weak and highly variable carbonate deposits. Suspected sinkholes have already been identified in some parts of the sea floor. There will be considerable technical challenges in developing appropriate foundation solutions and reliable geotechnical data is required.

A secondary consideration with respect to the weak ground conditions is that a study will need to be made to ensure that the construction of the bridge does not adversely affect coastal processes and lead to acceleration of the erosion of the north eastern corner of Malé Island.

2.9.5 Airport Height Restrictions

Construction of the bridge adjacent to the airport imposes stringent restrictions on the height of structure that can be built.

Considering the deep water it would be desirable to have long spans but the height restrictions places limits on the types of bridges and maximum spans that are achievable.

The span limitations become particularly significant in the reef slope areas where it is highly undesirable to locate a foundation. This means that the bridge must span across the slope areas.

2.9.6 Navigation

The bridge needs to have a relatively low profile due to the airport height restrictions. This will inevitably prevent large ocean going vessels from passing under the bridge. Therefore the largest vessels which must be able to continue to safely use the Gaadhoo Koa after construction of the bridge need to be identified to determine the navigation requirements. Larger vessels will need to use alternate passages into the atoll and stakeholder consultation on this issue has been carried out due to its importance.

2.9.7 Operation & Maintenance

The bridge will represent a large capital investment and it must therefore be operated and maintained to provide a high quality service level throughout a long service life. In the Maldives there are few, if any, bridges and therefore the institutions to operate and maintain the bridge do not exist.

Implementation of the project must therefore either include creation and capacity building of a dedicated institution or else turn over the operation to the private sector to attract experienced international organisations.

The design of the bridge should also seek to minimise the operation and maintenance burden.


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2.9.8 Traffic Congestion

There is a concern that the construction of the bridge could increase traffic congestion on the islands. This is an issue that needs to be addressed with a traffic impact assessment. Ways in which congestion can be tackled could include:

• Promoting public transport (buses) on the bridge

• Selecting a landing point which provides good traffic dispersal in Malé

• Implementing traffic improvements to facilitate dispersal

• Restricting types of vehicle that are permitted to use the bridge – this could mean private vehicles registered in specific areas or introducing a taxi zoning scheme to control numbers of taxis permitted to operate in specific areas

2.9.9 Impact on employment in ferry sector

Although the construction of the bridge will bring economic benefits to the majority of the population there is a concern that it will cause job losses for those currently either directly or indirectly employed in ferry operations.

At present, the Malé-Hulhumalé ferry service is operated by the Maldives Transport and Contracting Company (MTCC), a majority state owned enterprise which operates a number of ferry routes as well as providing other transport, logistics and construction services. There are 18 return trips per day and the journey takes approximately 20 minutes. The service is operated in a relatively efficient manner and prices appear to be based on cost plus profit. [6]

On the other hand, the Malé-Hulhulé service is provided by a number of individual operators working as an association or cartelized union as opposed to a company. The fare charged is relatively expensive compared to MTCC fares but there appear to be deliberate inefficiencies in the operation due to there being significantly more ferries operating than are actually required meaning that each vessel is only utilised for approximately 20% of the day. [6]

It is worth noting that the reduction in demand for ferries to Hulhumalé may be offset by increasing demand for ferry operations between Malé and the Eye of Maldives development meaning that some ferries could simply shift the route on which they operate. However, there could still be a net reduction in demand for ferry services and to avoid negative social impacts it is suggested that the government could implement reemployment schemes for affected persons.

It is possible that bus operations on the bridge could provide appropriate reemployment and this could be promoted by

• Retraining schemes (e.g. bus drivers licence, mechanics training etc.)

• Trade-in scheme whereby the government could provide mini-buses in return for ferries.

Bus operations on the bridge provide an opportunity for reemployment as well as promoting public transport


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• Direct intervention (employment quotas)

• Toll structure on the bridge which promotes the use of buses

There would be some costs associated with these schemes but these would be a small percentage in comparison to the overall project cost.

Since October 2010, MTCC has operated the Hulhulé to Hulhumalé bus service and there is clearly the possibility for their bus operations to expand to compensate for the loss of the Malé to Hulhumalé ferry service.

A decision will need to be taken on whether bus operations are to be carried out by a single franchised company or whether registered individuals operating non-scheduled services could also be permitted to operate buses. In Hong Kong, both systems are run in parallel (Figure 11) for the public light buses and a dual system could also be considered in the Maldives. This could provide greater opportunity for individual Malé-Hulhulé ferry operators to participate in the bus sector.

Figure 11 In Hong Kong, green minibuses operate a scheduled service, with fixed routes and fixed fares whereas red minibuses run a non-scheduled service according to market demand, although many routes may in effect become fixed over time.

2.9.10 Environmental impact

The bridge will be constructed over coral in a marine environment which means a careful assessment of the potential environmental impacts will be required and an environmental management plan will need to be developed.

2.10 Key Stakeholders

In developing a project of this nature, stakeholder consultation is important to ensure that views of interested parties are taken into account. During the course of this feasibility study a number of key project stakeholders have been identified:

• Government of Republic of Maldives

• Maldives Airport Company Ltd

• GMIAL

• Housing Development Corporation

• Environmental Protection Agency

• Maldives Ports Limited

• Maldivian Coast Guard

• Maldives Transport and Contracting Co.

• Malé to Hulhulé Ferry Operators

• STELCO

• Maldives Water & Sewage Co.

• Residents of Malé and Hulhumalé

Preliminary consultation was carried out with some stakeholders during the site visit and this report takes account of the views expressed. Further consultation will need to be carried out during later project stages.


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3 Alignment Options

3.1 Alternatives Considered

Ibrahim Nasir International Airport stands between Hulhumalé and Malé and any

road linking the two must pass either to the north or to the south of the runway.

Figure 12 Satellite image of Malé and Hulhumalé

The Hulhumalé to Hulhulé Link Road already connects to the southern end of the

runway and it is natural to consider extending this across the Gaadhoo Koa

channel to reach Malé, particularly since this road will also provide access to the

new International Passenger Terminal which is currently under development.

Alignment options passing to the north of the runway were briefly considered but

were discounted due to the significant additional cost and environmental impact

which would be associated with such a circuitous route. Therefore, all alignment

options considered pass to the south of the runway.

Three alignment options have been developed which are:

• Option A – which crosses the channel in a northeast-southwest direction and connects the southern tip of Hulhulé Island to the shallow water to the southeast of Malé. The alignment follows a gentle curve in order to stay clear of the sinkhole features observed further north in the channel and makes landfall close to the Tsunami Memorial.

• Option B – which is the most direct route across the channel and has the shortest shore to shore distance although it crosses the sinkhole area described in Section 2.8.4. This option is aligned in an east-west direction and the landing point on Malé is the vacant land to the north of the beaches

• Option C – which makes use of Funadhoo Island to separate the crossing into two parts albeit following a somewhat indirect route.


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These alignment options are illustrated in Drawings 217093/001 and 002 which are provided in Appendix A.

3.2 Landing Points and Traffic Dispersal

3.2.1 Option A

Alignment Option A makes use of the open area to the east of the junction between Ameene Magu and Marine Drive.

At this location the streets are relatively wide and offer excellent dispersal into the existing Malé road network. Space is available for construction of the bridge abutments although it is likely that the helipad may have to be relocated in order to provide sufficient space for tolling facilities.

This landfall also gives the best opportunity for future connectivity to Villingili, either via Ameene Magu or along the southern section of Marine Drive.

On Hulhulé Island this option provides excellent connectivity as the road would be a direct extension of the Hulhumalé to Hulhulé Link Road. A spur to the airport facilities west of the runway would of course be retained.

Figure 13 Landing Point A on Malé Island

Figure 14 Marine Drive


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Figure 15 General view of landing point (left) and Ameene Magu (right)

3.2.2 Option B

Alignment Option B would make use of the open land to the south of the STELCO substation on Malé Island which provides sufficient space for the bridge abutments, connection to the local road network and toll plaza. The ownership of this land was not established but it is not currently being used.

Figure 16 Landing Point B on Malé Island

The main disadvantage with this landing point is that Bodhuthakurufaanu Magu is quite narrow at this location meaning traffic dispersal would be difficult.

Figure 17 Bodhuthakurufaanu Magu

A


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Figure 18 Narrow one-way side street (location A in Figure 16)

On Hulhulé Island the traffic connection is the same as Option A.

3.2.3 Option C

The purpose of Option C is to make use of Funadhoo island and to split the crossing into two smaller stretches.

The landing point on Malé would be at or near Fisherman’s Park on the north side of the island.

Limited land is available at this location and it is likely that reclamation of some of the harbour area would be required if toll facilities were to be located on Malé Island. Alternatively the toll facilities could be at the Hulhulé end of the bridge although this would still require some reclamation.

The landing point is located close to the commercial centre of Malé and Bodhuthakurufaanu Magu is narrow at this location. Traffic dispersal would be difficult and would probably require road improvements and one-way systems.

Figure 19 Landing Point C on Malé Island


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Figure 20 Commercial buildings at Landing Point C

Although access is provided to Funadhoo the primary purpose of the link is for travel between Malé and Hulhumalé and the overall travel time will be increased by the indirect route.

3.3 Initial Sifting of Alignment Options

3.3.1 Floating Bridge Option

Two fundamentally different types of bridges will be considered in this report:

• Traditional fixed bridge with foundations on the sea floor

• Floating bridge

The feasibility of a floating bridge is very dependent upon the wave and current conditions. At the southern end of the Gaadhoo Koa channel rough wave conditions are expected which will exceed design values of previously constructed floating bridges. Even if a design solution could be arrived at it would lead to a relatively high risk solution which is not preferred. Therefore the floating bridge is only considered on Alignment Option C which is set back from the edge of the atoll and where the wave strengths will be significantly lower. There is also expect to be a reduction in current strength at this location.

3.3.2 Exclusion of Alignment Option B

It is possible to exclude Alignment Option B from further consideration at this early stage due to the unsuitable ground conditions. The alignment crosses an area of extensive karst features (sinkholes) which would make selection of suitable locations for the bridge foundations difficult if not impossible. Furthermore, the west abutment of the bridge would be located on the steep margin of Malé Island which is vulnerable to slope collapse.

Alignment Option A crosses the channel further to the south away from the observed areas of sinkholes and the landfall on Malé Island is the south eastern point where slope failures have not been observed. The engineering feasibility of bridge construction on this alignment is much more favourable.


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In terms of traffic, alignment Option Ais also more favourable than Option B since it can connect directly to wide southern section of Marine Drive providing dispersal through Majeedi Magu or Ameene Magu. This option will also facilitate future connectivity to Villingili Island.

The disadvantage of Option A is that it will have a significant impact on the wave formation at Surfers Beach which is likely to be detrimental to the quality of surfing. This impact is partly mitigated by the bridge giving easier access to the beaches on Hulhumalé.

Despite this undesirable impact on leisure resources, Option A must be considered preferable to Option B since the latter is unlikely to be feasible as explained above. Option B is therefore excluded from further consideration.

3.3.3 Fixed Bridge on Alignment Option C

If it were highly desirable to include a link to Funadhoo as part of this study then the construction of a fixed bridge on Alignment C could be achievable. However, we have not considered this option because:

• The overall length of the bridge would be greater on Alignment C (and the water depth is greater) so the cost would be higher

• The travel time would be greater between Malé and Hulhumalé thus the effectiveness of the bridge in achieving its primary function would be reduced

• Traffic dispersal on Malé is less favourable for Alignment C

• The reef geology is less stable at the Alignment C landing point

For these reasons, we have only considered a floating bridge on Alignment C.

3.3.4 Summary of Initial Sifting Exercise

The initial sifting exercise is summarised in the table below which shows which options are considered further and why:

Bridge Type Alignment A Alignment B Alignment C

Fixed Bridge � Considered further � Unsuitable ground conditions – high risk

� High cost and poor functionality

Floating Bridge � Wave conditions are too rough – high risk. � Considered further


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4 Airport Operational Issues

4.1 Airport Height Restrictions

The most significant operational issue associated with the airport is the height restrictions that must apply.

The airspace around airports is to be maintained free from obstacles so as to permit aircraft operations at the airport to be conducted safely and to prevent the airport from becoming unusable by the growth of obstacles around the airport. This is achieved by establishing a series of Obstacle Limitation Surfaces (OLS) that define the limits to which objects may project into the airspace.

As a bridge would be located on the south west side of the airport island, we have established the OLS for Runway 36 (south part of the runway) and have defined the height limits for objects in this area.

Over the next years the airport will undergo major modifications with the objective to improve safety and security standards at the airport. From the Malé International Airport Draft Master Plan [1] we have gathered the following details regarding the implications for Runway 36:

• Provision of a minimum 90 metre Runway End Safety Area (RESA) for Runway 36;

• Installation of a blast fence, with frangible mounting to protect vehicles on the perimeter road.

The Draft Master Plan states that the blast fence will be of 3.8 metres height and 60 metres length and will provide protection for vehicles, including catering trucks, from take-off thrust jet blast from four-engine aircraft such as the B747-400. A more recent CAD plan obtained from the Client shows the blast fence now extended to 220m length but it is assumed the height is not significantly changed.

We have established the OLS based on International Civil Aviation Organization (ICAO) standards and have used the following assumptions:

• Runway Code Number 4, Instrument Runway

• Take-off climb surface of Runway 36 located 190 m north of blast fence

• Location of threshold 36 will remain unchanged

• No clearway provided at Runway 36

We have set up the OLS based on these assumptions and have identified the following surfaces as critical for the elevation of infrastructure, like the bridge, road connections or other installations in the south or south west of Runway 36:

a) Inner Horizontal: 45m height

b) Transitional: 14.3% slope

c) Take-Off Climb: 2.0% slope

d) Approach: 2.0% slope


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The established OLS can be seen in Figure 21 below. Each contour shows an elevation increase of 5 metres. The height of the lowest contour equals the height of the relevant OLS reference point (“0”) which is the runway elevation. This has been taken as 2m above mean sea level.

Figure 21 Critical OLS (Source: Arup)

These surfaces have been plotted on Drawings 217093/001 and 002 and have been used in the development of the bridge options. It is important to note that these OLS were established by Arup for the purpose of this study. In case more detailed studies are carried out, the OLS and runway elevation should be confirmed by the airport authorities.

The modifications to the runway ends address two major safety issues, the introduction of a RESA and the installation of a blast fence. With lengthening the runway by 140 metres to the north to maintain the Take-Off Run Available (TORA), the Take-Off Climb surface for Runway 36 is moved north which provides sufficient height for installing a 3.8 metre blast fence. The road south of the blast fence must be restricted to vehicles of less than approximately four metres height.

We have observed that vehicles operating on the road to the west of the runway result in a transient obstacle in the Transitional OLS and this is understood to be an acceptable minor non-compliance. However, for the purpose of establishing the alignment of the bridge we have aimed for a minimum clearance of 4.0 metres between the road level and both the Take-Off Climb and the Approach OLS. This will allow vehicles to operate on the road without becoming an obstacle. These surfaces are considered more critical to aircraft safety than the Transitional OLS.

4.2 Ground Transportation

The construction of a bridge will change the quantity and quality of traffic between the Malé and Hulhulé islands.

a)

b) b)

c) d)

d)


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The largest segment of passengers at MLE are international tourists of which approximately 45% transfer to domestic air services. The majority of the remainder transfer to resort hotels by speedboat. Only a limited number of tourists visit Malé Island.

At present both the resort speedboats and the Malé-Hulhulé ferry services operate from the harbour area to the west of Hulhulé Island. However, with construction of the new International Passenger Terminal to the east of the runway the resort speedboats will operate from within the seaplane lagoon meaning that the western harbour area will be solely for the ferry services and airport operations.

Figure 22 Harbour facilities after construction of new International Passenger Terminal

Currently, the speedboat and ferry terminals are the main interchange station between air and ground level transport. With construction of the bridge there would be continued demand for harbour areas to facilitate transfer to the resort speedboats but there will also be demand for an interchange station next to the passenger terminal which connects various road traffic transportation modes. The interchange station could host pick up, drop off and short term parking facilities for the following modes of transportation:

• taxi • limousines • hotel and tour operator buses • scheduled buses

The current airport masterplan allows for the case where the bridge is constructed by providing a surface parking area to the north of the passenger terminal building to cater for anticipated demand. It is possible that this could eventually be further developed into an interchange station with the loss of area for at grade parking being compensated with the construction of a multi story car park.

After construction of the bridge the cargo quay and Malé Island ferry may no longer be required. However, there will be a need for road cargo unloading and bus depot facilities. It is possible that these could be located in the areas vacated by the sea based ferry and cargo operations.

Resort boat

facilities

Cargo quay

Male Island

ferry Marine rescue and

firefighting


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4.3 Traffic Volume

We are not aware of any studies that have been carried out that estimate the future sea and road traffic volume.

The road to the south of the airport is currently used for public transportation between the airport and the development of Hulhumalé and also used as airport service road between the airport functions to the west and the east of the runway. The road has sufficient width for 2 lane traffic (approx 7.5m).

The traffic on this road is likely to increase significantly after construction of the bridge. There will be three components to the traffic:

• Traffic between Malé and Hulhumalé

• Traffic between Malé and the main airport facilities to the east of the runway

• Traffic between the airport facilities to the east and west of the runway

It can be surmised that the most heavily trafficked portion of the Malé to Hulhumalé road will be the section between the bridge and the International Passenger Terminal and that any traffic studies to be carried out will need to consider the airport landside transport infrastructure system as well as the traffic between Malé and Hulhumalé. It is possible that this section of road should be widened to a dual two lane carriageway.

4.4 Conflicts Between Road and Air Traffic

The airport improvements plan to solve the conflicts between road and air traffic at the Runway 36 southern threshold as required by the concession. However, the road traffic on the Hulhumalé to Hulhulé Link Road in the north east of the future passenger terminal building is not entirely independent from take-off and landing activities from the sea plane runways. On a particular zone of the road signage is currently provided instructing road traffic to give way for sea planes.

As the traffic volume will increase and the type of traffic will change with the introduction of a bridge, this conflict will become more severe and the current solution may not be acceptable.

The optimum solution for road traffic would be to relocate the runways but this is likely to be either very expensive or highly disruptive to airport operations. An alternative concept could be to close the road during take-offs or landings using traffic signals and a barrier as is currently adopted at Runway 36 (refer Figure 23). Since not all sea plane movements cause conflict with the road this solution will also allow air traffic control authorities to determine when traffic should be stopped. At present individual drivers use their judgement as to whether the flight path requires them to give way.


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Figure 23 Signalised traffic control at Runway 36 – this solution could be adopted on the Hulhumalé-Hulhulé Link Road to deal with conflicts between road traffic and sea planes

Whether this solution is feasible will depend on the future road and sea plane traffic volume. Also critical will be to develop a reliable technical solution together with operational procedures that will be accepted by the authorities.

4.5 Airport Emergency Vessels

The airport operates a number of emergency vessels. These are discussed in Section 5.2.1 with respect to the need to ensure these vessels can navigate under the bridge.

4.6 Conclusions

The airport height restrictions are very influential to the structural options that can be considered for the bridge. In view of the deep water, fast currents and ocean swells that are found in the Gaadhoo Koa, one option that could be considered would be to construct a bridge from shore to shore without any intermediate supports in the channel. However, this would require very tall towers which would violate the height restrictions.

Super long span structures

Stonecutters Bridge, with a span of 1,018m could cross the Gaadhoo Koa channel without any foundations in the water.

However the tower is 300m tall making this kind of long span bridge completely unsuitable for construction adjacent to the airport runway.

In addition to these restrictions it is apparent that the construction of the bridge will have an influence on the airport landside transport infrastructure system. This has already been considered within the airport masterplan which considers the scenario of the case of the bridge being constructed. However, as the planning of the bridge progresses there may need to be further coordination between the airport development and the government plans for public transport and road infrastructure between Malé and Hulhumalé.


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5 Navigation Issues

5.1 Marine Activity

A wide variety of vessels are found in and around the North Malé Atoll including large ocean going vessels as well as small powerboats, ferries and dhoni’s.

Container ship (MV Seaboxer) Cruise ship (Nautica)

72’ sailing yacht 140’ motor yacht

Figure 24 Examples of large vessels (airdraft greater than 20m)

50’ motor yacht Live aboard dive vessel

Luxury tourist dhoni Maldivian Coast Guard CGS Huravee

Figure 25 Examples of medium sized vessels (airdraft between 5m and 20m)


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Local ferry Typical speedboat

Fisherman’s dhoni Maldivian Coast Guard patrol craft

Figure 26 Examples of small vessels (airdraft less than 5m)

The main berthing areas in Malé include facilities for the airport ferry, the commercial harbour as well as the marina and ferry berth to the south of the island. There is a commercial anchorage inside the atoll to the north west of Malé Island.

Figure 27 Berthing areas on Malé

In the commercial harbour operated by Maldives Ports Limited, large cargo vessels are handled at the alongside berth (Magathu Faalan) as well as at anchorages offshore using barges. Most of the container ships are handled at the


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alongside berth. The port handles all types of cargo except dry bulk, liquefied petroleum and gases. The airport ferry mainly serves passengers travelling to and from Ibrahim Nasir International Airport.

Figure 28 Passages currently used to enter the atoll

Referring to Figure 28, the Gaadhoo Koa is the passage between the reefs fringing Malé and Hulhulé which is about 740 m wide at its outer end and has a depth of 35m in the fairway. At its inner end the passage divides, passing each side of Funadhoo with deep water in both channels. The Gaadhoo Koa is the recommended approach to the anchorage area north of Malé for all vessels at safe speed.

The northern entrance to the atoll is through Bodukalhi (Kanduoiygiri Passage). Malé Villingili passage is another safe passage for safe entrance to Malé


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anchorage. but “mariners should exercise caution when using this channel as a shoal of 5.0m lies in the centre of the channel.” [9]

5.2 Airdraft

5.2.1 Airport emergency vessels

As shown in Figure 22, the airport has a dock for marine rescue / firefighting vessels. These would need to be rapidly deployed in the event of any incident which involved an aircraft either overrunning or landing short of the runway. It is critical that the bridge provides sufficient airdraft for these vessels.

The firefighting vessel has an airdraft of approximately 7m and this is the minimum requirement for the bridge. This requires that the minimum soffit level of the bridge shall be:

MHHW +0.9mCD

Vessel Height 7.0m

Safety Margin 1.5m

Minimum Soffit Level 9.4mCD

5.2.2 Controlling factors

A number of controlling factors limit the airdraft that will be available under the bridge:

• Airport height restrictions • Maximum gradient of road • Minimum structural depth • Safety margin

These factors are illustrated diagrammatically below:

Figure 29 Limiting factors controlling airdraft

• The approach surface to the airport runway means the road has to be at a relatively low elevation on the shore of Hulhulé Island.

• The road can climb towards the centre of the channel but the gradient has a maximum value which limits the elevation of the road at the navigation channel.

• The bridge itself has a structural depth which has a minimum value which means that the underside of the bridge is at a lower elevation than the road.

• Finally, it is normal to establish a safety margin to allow for pitch and heave of the vessel as well as human error.


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In combination these factors mean that the maximum vessel airdraft that can be provided under the bridge is approximately eight to twelve metres.

This means that after construction of the bridge large vessels would not be able to navigate through the channel but smaller vessels including the airport firefighting vessel would be able to including the airport emergency vessels.

5.2.3 Impact of limited airdraft

Construction of a bridge across the Gaadhoo Koa will inevitably restrict the shipping that is able to use the channel. However, both Maldives Ports Ltd and the Maldivian Coast Guard were consulted on this issue and neither stakeholder raised any concern over the airdraft being limited to around 8m. It was noted that there are several alternative channels into the atoll and that in the future it is intended to shift the commercial harbour to Gulhi Falhu in any case.

Therefore, the impact of limiting the airdraft through the Gaadhoo Koa is that alternative channels must be used for large vessels to enter the atoll. This is likely to require:

• Additional navigation marking to be provided on alternate channels

• Revision of recommended navigation procedures

• Possible revision of pilot boarding stations

• Revision of maritime charts to show airdraft restriction

5.2.4 Floating Bridge

For the floating bridge option it is important for the stability of the structure to keep the bridge relatively low. If the centre of gravity is too high then the pontoons will become unstable and could invert.

In general, the soffit clearance above water is maintained at 5.0m in permanent load conditions which will allow safe passage of vessels up to around four metres in height. This means that only very small vessels can pass such as the resort speedboats and local ferries.

Because of the need to provide passage for the airport emergency vessels, one span of the bridge will be provided with a soffit clearance 8.5m above water. This may require the pontoons to be increased in size for this particular span.

5.3 Span and Marine Safety

5.3.1 Ship Domain Theory

Whilst the available airdraft beneath the bridge represents a physical constraint to the size of vessel which can pass under the bridge, the span is related to marine safety. If the span is too little then vessels will be confined to a narrow channel and are more likely to have to carry out evasive manoeuvres in the vicinity of the bridge. This in turn leads to a greater risk of ship to ship collision compared to unrestricted waters.


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One way of assessing the required span is based on ship domain theory [8]. This is the observation that ships navigate within a “safety bubble” known as a domain and that when fixed objects or other ships impinge on this domain the ship may carry out evasive actions.

One Way Traffic Two Way Traffic

Figure 30 Ship domain theory

5.3.2 Traditional Bridge Options on Alignment A

Due to the deep water in the Gaadhoo Koa, the minimum span which is under consideration is approximately 200m. At the same time, the airdraft limits means that only small vessels can pass under the bridge.

A span of 200m means that ships with a length less than or equal to around 20m to 25m can safely pass each other under the bridge at free navigation speeds. This will encompass the vast majority of traffic under the bridge including ferries and speedboats.

Ships up to around 110m length can safely pass under the bridge although the ship’s captain would consider the span to be restricted waters and is likely to travel at reduced speed and pass through the centre of the channel and timing the passage to avoid ship to ship encounters under the bridge.

The traditional bridge options on Alignment A will cut squarely across the straight navigation channel in open water where there is good visibility and few vessels will be making manoeuvres or crossing the channel. The marine risk associated with this option given the long span of the structure is very low.

5.3.3 Floating Bridge Option on Alignment C

For the floating bridge option the span will be approximately 100m. However, for this option the airdraft is also generally significantly lower meaning that only the smallest vessels (resort speedboats and local ferries) will be able to pass. Based on ship domain theory the span will be sufficient for these vessels.

However, the bridge is close to the entrance of harbour areas on both Malé and Hulhulé Island where vessels may be manoeuvring in different directions. Furthermore, the pontoons of the floating bridge will be relatively restrictive to visibility and it will not always be obvious which span a particular vessel intends to pass under. Some vessels may wish to pass obliquely under the bridge.

For these reasons there is a slightly higher degree of marine risk associated with the floating bridge option on Alignment C.


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5.4 Ship Impact

Bridges in navigable waters must be designed considering the possibility of ship impact. This means considering the scenarios under which a vessel could become aberrant within the vicinity of the bridge (whether due to mechanical failure or human error) and could then go on to collide with the bridge.

The forces due to ship impact from large vessels are very significant and can be disastrous. However, as has been discussed above, the large vessels will no longer be able to use the Gaadhoo Koa after construction of the bridge so they should not be navigating in the vicinity of the bridge.

Medium and small vessels may still navigate under or near the bridge and a marine risk assessment needs to be carried out to determine the probability of different sizes of vessels impacting the bridge, the likely impact speeds and therefore the ship impact forces that the bridge must be designed for. Possible ship impact scenarios include:

• Vessel becomes aberrant and collides with the piers of the bridge (hull impact)

• Oversized vessel attempts to navigate under the bridge and collides with the deck (mast / deckhouse impact)

• Ship at anchorage breaks free of its moorings during a storm and drifts towards the bridge colliding with either pier or deck

The objective of the marine risk assessment will be to determine the necessary navigation installations and procedure to maintain safety as well as to define the ship impact forces which the bridge must be designed for.

5.5 Conclusions

The Maldives is an archipelago and marine traffic is an important aspect of everyday life in the islands. Construction of a bridge across the Gaadhoo Koa will have a significant influence on how vessels navigate around Malé, especially the larger commercial vessels. However, due to the large number of entries into the atoll it has been confirmed by key stakeholders that there will be no adverse impact to marine operations if appropriate additional navigation aids are provided for shipping using alternate channels.

All bridge options will provide sufficient airdraft for resort speedboats, local ferries and the airport firefighting vessel to pass under the bridge and some options will provide greater airdraft to allow slightly larger vessels to pass.

The span of all bridge options is considered sufficient for safe navigation but the location of the floating bridge on Alignment Option C is slightly less favourable than Alignment Option A and may cause some navigation conflicts.

For all bridge options, a marine risk assessment will be required to determine the necessary navigation installations and procedure to maintain safety as well as to define the ship impact forces which the bridge must be designed for. Since large ocean going vessels will not pass under the bridge the ship impact forces are likely to be manageable. However, the possibility of a large vessel breaking free of its anchorage and drifting into the bridge does need to be considered.


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6 Environmental Issues

6.1 Introduction

The purpose of this section is to provide a preliminary environmental assessment of the proposed bridge options with respect to ecology, water quality, air quality and noise. Relevant environmental legislations, guidelines and environmental baseline information are collated. Key environmental impacts during the construction and operation of the proposed road and bridge link are identified. Design approaches to avoid and minimize potential environmental impacts, mitigation measures to address the potential impacts and further investigations are recommended, where applicable.

It should be noted that this section only presents a preliminary assessment and detailed studies and/or assessments need to be carried out during later design stages.

6.2 Environmental Legislation, Guidelines, Policies and International Conventions

6.2.1 Relevant Environmental Legislation and Guidelines

Environmental Protection and Preservation Act of Maldives The Articles of the Environmental Protection and Preservation Act (Act No. 4/1993) addresses the following aspects of environmental management:

• Guidelines and advice on environmental protection shall be provided by the concerned government authorities;

• Formulating policies, rules and regulations for protection and conservation of the environment in areas that do not already have a designated government authority already carrying out such functions shall be carried out by the Ministry of Environment, Energy and Water (MEEW);

• Identifying and registering protected areas and natural reserves and drawing up of rules and regulations for their protection and preservation;

• An Environmental Impact Assessment shall be submitted to MEEW before implementing any developing project that may have a potential impact on the environment;

• Projects that have any undesirable impact on the environment shall be terminated without compensation;

• Disposal of waste, oil, poisonous substances and other harmful substances within the territory of the Republic of Maldives is prohibited. Waste shall be disposed of only in the areas designated for the purpose by the government;

• Hazardous / Toxic or Nuclear Wastes shall not be disposed anywhere within the territory of the country. Permission should be obtained for any trans-boundary movement of such wastes through the territory of Maldives;

• The Penalty for Breaking the Law and Damaging the Environment shall be specified;


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• The government of the Maldives reserves the right to claim compensation for all damages that are caused by activities that are detrimental to the environment.

Environmental Impact Assessment Regulation 2007 The MEEW issued the EIA Regulation in May 2007 which guides the undertaking of the Environmental Impact Assessment/Initial Environmental Examination (EIA/IEE) process in the Maldives. The EIA Regulation provides a comprehensive outline of the EIA/IEE process beginning from the application to the details of the contents, the minimum requirements, roles and responsibilities of the consultants and proponents, the format of the EIA/IEE report etc.

Ban on Coral Mining Coral mining from the house reef and the atoll rim has been banned through a directive from the President’s Office dated 26

th September 1990. Coral is

prohibited to be mined at any stage of the project.

Guidelines for Domestic Wastewater Disposal Developed by the Maldives Water and Sanitation Authority and implemented by the Environment Protection Agency, this guideline serves to improve public heath by regulating the disposal of domestic wastewater and therefore providing a cleaner and safer environment through improved sanitation. When handling wastewater from construction workforce these guidelines should be considered.

Ambient Air / Noise and Water Quality Standards The Republic of Maldives lacks the necessary environmental standards for the measurement of ambient air, noise and water quality. Therefore, standards of the World Health Organization (WHO), those of international recognition, or standards of developed countries should be used.

6.2.2 Relevant Policies

National Energy Policy The National Energy Policy looks at existing and emerging energy issues and constraints of the country. With a focus on sustainable supply and consumption, the policy also addresses issues of the environment, renewable energy and energy efficiency. According to the policy document, 3% of energy is from biomass and solar and the remainder is from refined petroleum products. Diesel fuel accounts for 83% of the total energy consumption in the Maldives.

Carbon Neutral by 2020 In March 2009, President Nasheed announced the target to make Maldives carbon neutral by 2020. Hence, in the implementation of the project, careful attention needs to be given to ensure energy efficiency and reduce transport related fuel consumption.

National Adaptation Programme of Action (NAPA) The adaptation policies and strategies of the Maldives are given in the Maldives National Adaptation Programme of Action [10]. The first component of the Maldives Adaptation Framework is climate change-related hazards. These include sea level rise, precipitation, temperature and extreme events.


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6.2.3 International Conventions

Convention on Biological Diversity The Maldives is a party to the United Nations Convention on Biological Diversity. The objective of the convention includes the following: “the conservation of biological diversity, the sustainable use of its components and the fair and equitable sharing of the benefits arising out of the utilization of genetic resources, including by appropriate access to genetic resources and by appropriate transfer of relevant technologies, taking into account all rights over those resources and to technologies, and by appropriate funding”. The proposed development mainly falls on highly developed areas which are not recognised for their ecological value [1]. Therefore, a major loss of biodiversity is considered unlikely.

Climate Change Convention and Kyoto Protocol The Maldives is a party to the United Nations Framework Convention on Climate Change (UNFCCC) and the Kyoto Protocol to the UNFCCC. The objective of the Convention is to stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. The greenhouse gas inventory of the Maldives forms an integral part of the First National Communication of the Maldives to the UNFCCC. In March 2009, the President of the Maldives has announced the target to make Maldives carbon neutral by 2020.

Third National Environment Action Plan (NEAP III) The aim of NEAP III is to protect and preserve the environment of the Maldives and to sustainably manage its resources for the collective benefit and enjoyment of present and future generations. The principles outlined in NEAP III include the following:

• Environmental protection is the responsibility of every individual;

• Achieve results – The actions, activities, regulations, supervision, reporting, incentives, information and advice for environmental management shall be directed and well co-ordinated to achieve the results the citizens want;

• Promote and practise sustainable development;

• Ensure local democracy;

• Inter-sectoral co-ordination and co-operation;

• Informed decision making;

• Precaution first;

• Continuous learning and improvement;

• Right to information and participation; and

• Environmental protection complements development.

NEAP III contains environmental policies and guidelines that should be adhered to in the implementation of the proposed project activities.


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6.3 Baseline Conditions

Baseline information in the vicinity of the project site has been collected through desktop study. The enviroconditions (which are described in Section quality and noise.

6.3.1 Ecology

Protected Areas There are no protected areas around the project site. The nearest protected areas are Kuda Haa Dive Site (1995) and Banana10-12km away from the proposed project sites as shown in Nevertheless, the Maldives project site approximately 400m, 500m and 600m from 3 respectively.

Figure 31 Protected areas around the proposed site

Terrestrial Ecosystem The Malé and Hulhulé Islands are highly developed. The habitat around theProject site could be categorized into three types, i.e. developed area, plantations and lagoons as shown in land uses such as airport, buildings, roads and other infrastructecological significance due to their disturbed nature. The plantations are mainly established for urban landscape purpose and are of limited ecological importance. Based on the flora survey conducted during OctInternational Airport EIA Studypalm (Cocos nucifera) which account for more than 57%. Protected species of Banyan trees (Ficus benghalensisabout 4.5% during the survey.

The diversity of fauna in the Maldives is considered limited. Majority resides in the forests of uninhabited islands with limited human disturbance. Since both Malé and Hulhulé Islands are highly developare considered of low ecological value. Based on the fauna survey conducted during Oct-Nov 2010 formosquitoes, lizards, rats, giant ants, common ants, cockroaches and f


Baseline Conditions

Baseline information in the vicinity of the project site has been collected through desktop study. The environmental baseline data includes environmental

are described in Section 2.8.3), ecology, water quality, air

There are no protected areas around the project site. The nearest protected areas are Kuda Haa Dive Site (1995) and Banana Reef Dive Site (1995) which are about 12km away from the proposed project sites as shown in Figure 31

Nevertheless, the Maldives Victory (refer Section 6.3.5) is located within the proximately 400m, 500m and 600m from alignment options 1, 2 and

Protected areas around the proposed site

The Malé and Hulhulé Islands are highly developed. The habitat around theProject site could be categorized into three types, i.e. developed area, plantations and lagoons as shown in Figure 32. The developed areas cover all the urbanised land uses such as airport, buildings, roads and other infrastructures and are of low ecological significance due to their disturbed nature. The plantations are mainly established for urban landscape purpose and are of limited ecological importance. Based on the flora survey conducted during Oct-Nov, 2010, for the Malé nternational Airport EIA Study [1], the dominant species in Hulhulé is Coconut

) which account for more than 57%. Protected species of Ficus benghalensis) were observed in the Island, accounting for

about 4.5% during the survey.

The diversity of fauna in the Maldives is considered limited. Majority resides in the forests of uninhabited islands with limited human disturbance. Since both Malé and Hulhulé Islands are highly developed, fauna resources in the two Islands are considered of low ecological value. Based on the fauna survey conducted

for the Malé International Airport EIA Study, crow, mosquitoes, lizards, rats, giant ants, common ants, cockroaches and f


Page 36

Baseline information in the vicinity of the project site has been collected through environmental

ecology, water quality, air

There are no protected areas around the project site. The nearest protected areas Reef Dive Site (1995) which are about

31. is located within the nment options 1, 2 and

The Malé and Hulhulé Islands are highly developed. The habitat around the Project site could be categorized into three types, i.e. developed area, plantations

. The developed areas cover all the urbanised ures and are of low

ecological significance due to their disturbed nature. The plantations are mainly established for urban landscape purpose and are of limited ecological importance.

Nov, 2010, for the Malé , the dominant species in Hulhulé is Coconut

) which account for more than 57%. Protected species of sland, accounting for

The diversity of fauna in the Maldives is considered limited. Majority resides in the forests of uninhabited islands with limited human disturbance. Since both

ed, fauna resources in the two Islands are considered of low ecological value. Based on the fauna survey conducted

the Malé International Airport EIA Study, crow, mosquitoes, lizards, rats, giant ants, common ants, cockroaches and few common


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bird species were observed in Hulhulé Island. No endangered or rare animal species were identified in the survey.

Figure 32 Habitat map

Marine Life Qualitative and quantitative surveys were conducted during OctMalé International Airport EIA Studyin Figure 33 and the results are summarized in paragraphs below.

Figure 33 Marine surveys conducted for MLE


bird species were observed in Hulhulé Island. No endangered or rare animal species were identified in the survey.

Qualitative and quantitative surveys were conducted during Oct-Nov 2Malé International Airport EIA Study [1]. The locations of survey sites are shown

and the results are summarized in paragraphs below.

Marine surveys conducted for MLE Environmental Impact Assessment


Page 37

bird species were observed in Hulhulé Island. No endangered or rare animal

Nov 2010 for the . The locations of survey sites are shown

Environmental Impact Assessment


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Site 1 Visual inspections were conducted at Site 1. The marine benthos at this site consist mainly of coral rock and rubble with occasional coral heads (Pocillopora meandrina, Favia sp., Acropora sp.) attached with some of them entangled in fishing lines. The most abundant fish species at this site are the Damselfish Abudefduf vaigiensis and Chrysiptera biocellata, Soldierfish Myripristis sp. and Sweeper Pempheris venicolensis. Surgeonfish Acanthurus lineatus and A. nigricauda, Butterflyfish Chaetodon xanthocephalus and C. citrinellus and the “Monocle Bream” Scolopsis bilineatus, “Moorish Idol” Zanclus cornutus as well as Squirrelfish Neoniphon samara were also observed.

Site 2 Visual inspections were also conducted at Site 2. Fish species at this site are restricted to patches of scattered live corals (Acropora sp., Pocillopora meandrina,and Porites sp.). Thalassoma Hardwicke, T. janseni as well as other wrasses, Acanthurus triostegus, Stegastes nigricans and other Pomacentridae were observed. The visibility of Site 2 is lower than that of Site 1 and a small fraction of beach is entirely polluted by solid wastes (such as foam, Styrofoam, plastic bottles and metal waste etc.).

Site 3 Quantitative reef benthos and fish surveys were conducted at Site 3. Reef benthos survey was carried out at 8 and 15 m depth with a 20m transect line parallel to the reef. The fish census was performed at 8 m depth within a belt transect of three metres width along the 20m transect line.

Reef Benthos

Depth 8 metres: Live coral cover was about 26.5% coverage ± 7.89% (mean ± SE) in 8 metres depth at site 3. Acroporidae were the most abundant coral family, covering 13.3% of the transect, followed by Poritidae with 5.7%. Other coral species such as Faviidae (Favia, Favites, Pavona) and Merulinidae (Hydnophora) were less abundant. No bleached, dead or broken corals were found during the survey.

Depth 15 metres: Live coral cover in 15 metres depth was generally lower than that in 8 metres depth. Coral family composition (Acroporidae, Pocilloporidae, Poritidae and other families) was equally distributed in this depth of the site. No bleached , dead or broken corals were found during the survey.

Fish Census

Fish were generally abundant with at least 7 families within the 20×3m belt transect lines, including Caesionidae (Caesio xanthonota, C. varilineata), Acanthuridae (Acanthurus spp.), Pomacenttridae (Chromis viridis, Pomacentrus spp.), Labridae (Thalassoma spp.), Chaetodontidae (Chaetodon kleinii), Lutjanidae (Lutjanus kasmira) and Cirrhitidae (Paracirrhites forsteri).

In addition to fish present within the transect, various other families/species were also observed in close vicinity, such as Zanclidae (Zanclus cornutus), Serranidae (Pseudanthias squamipinnis) and Serranidae (Cephalopholis argus, Plectropomus laevis).

Rare and Endangered Species The Republic of Maldives prohibits the killing, catching or extracting any of the


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following within the Exclusive Economic Zone of the Maldives: Black oral, Triton Shell (Conchs), Giant Clams, Berried female lobsters and those less than 25cm in total length, marine turtles, Napolean Wrasse, dolphins and whales. According to the surveys conducted in the November 2010 Malé International Airport EIA no rare and endangered species were observed in Hulhulé reef.

6.3.2 Water Quality

Baseline marine water quality data was derived from [1]. Water quality is generally uniform at the sites observed.

Chlorophyll data presented in [1], suggests that concentration/productivity in and around Malé-Hulhulé area is low with a maximum chlorophyll value of 3 mg/m

3.

These values are within the typical range of clear coral dominated waters.

6.3.3 Air Quality

Ambient air quality monitoring was conducted at four locations from October to November, 2010 for the Malé International Airport EIA [1].

The ambient air quality monitoring data indicated that all parameters were within the WHO guidelines for ambient air quality. The minimum, maximum and 24-hour average from all four monitoring locations were extracted and are presented against the WHO Guidelines. All results fall well below the guideline limits except for one sample for NOx taken at the Central Store on Hulhulé Island.

Parameter Minimum Maximum 24 hr Ave WHO Guidelines

PM10, µg/m³ 15 32 23.2 50 (24-hour mean)

PM2.5, µg/m³ 4.1 9.3 6.4 25 (24-hour mean)

SO₂, µg/m³ 4.1 7.7 5.3 20 (24-hour mean)

NOx, µg/m³ 4 62 9.8 20 (24-hour mean)

CO, µg/m³ 32 142 67.8 -1

Notes:

[1] WHO Guidelines do not provide a 24-hour mean value. 10 µg/m³ for 8-hour average period is provided.

6.3.4 Noise

A baseline condition of the noise environment has been derived from [1]. The locations for which data is available are in Hulhulé, Malé and Hulhumalé Islands. Hence, it provides a representative measurement for the study area.

The ambient noise levels are considered as moderate to high when compared to

international standards such as the WHO Guideline Values for Community Noise

in Specific Environments. According to [1] this is due to the close proximity to

the sea, windy conditions, closely packed residential areas and movement of

boats. The WHO guideline for industrial, commercial, shopping and traffic areas

is set at 70dB (LAeq) for daytime hours and suggest a 5-10dB decrease during the

night. Most of the site locations fall within this category and comply with the

recommended LAeq for daytime. However, a few commercial and industrial sites

would exceed the upper limit of 60-65dB during the night (e.g.. City Bakery,

Maldives’ Port Authority, Bank of Maldives and STELCO Power House).


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6.3.5 The Maldives Victory

The Maldives Victory is the wreck of a 110m long 35,000 tonne freighter which ran aground and sank on the western side of Hulhulé Island in 1981. The wreck lies in approximately 35m of water and is a very popular recreational dive site. In the three decades since the wreck sank it has attracted a wide variety of marine life which is now well established.

The wreck is considered an artifact of significant environmental importance and the construction of the bridge should not be allowed to have any adverse impact on the ecology of the wreck.

6.3.6 Beaches on Malé

There are two beaches on the eastern end of Malé which are important leisure facilities for the island. Surfer’s Beach and the Artificial Beach. Construction of a fixed link would make it easier for Malé residents to access the beaches of Hulhumalé but nevertheless the construction of the bridge should, if possible, avoid undesirable impacts that would reduce the quality of these existing leisure resources.

6.4 Potential Impacts and Mitigation Measures

6.4.1 Ecology

Potential Impacts During Construction Phase Some physical loss of marine habitat (seabed and water column) would result from construction works at each location where piers are installed to support the bridge deck. To provide access for construction equipment and labour, each pier construction site would include an area of works which could be considered as temporary marine habitat loss. As Malé and Hulhulé Island are located in a large coral reef system, direct loss to coral species and associated fauna is anticipated. According to [1], rare and endangered species are not observed in the Hulhulé reef.

Other potential ecological impacts may result from water quality deterioration from the following activities:


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• Pier site dredging

• Construction site runoff

• Wastewater from construction activities

• Accidental spillage of works site chemicals

As the landing sites on either side of the bridge development are both recognized as highly developed with low ecological significance, no terrestrial ecological impact is anticipated.

Mitigation Measures During Construction Phase In order to minimise ecological impacts within the project site the following mitigation measures are recommended:

• Minimization of pier locations during detail design (i.e. longer spans)

• Transplantation of living coral and/or compensatory mitigation of reef area loss by creation of artificial reef

• Deployment of silt screens during dredging activities for pier bases

• Good site practice including site runoff control on terrestrial areas and prevention of construction waste, including hazardous waste, entering the sea

Potential Impacts During Operational Phase After construction of the project, the temporary marine works areas should be self-restored but the Benthic habitats occupied by the pier footprint would be permanently lost. Marine habitat loss would be minimal as bridge piers would only occupy a small proportion of the sea area along the bridge alignment.

Indirect impacts associated with water quality deterioration could result from road surface runoff which is marginally contaminated by vehicles.

Mitigation Measures During Operational Phase As a precautionary measure surface road runoff can be controlled by implementing proper drainage systems with silt traps and oil interceptors. Maintenance at regular intervals is recommended.

6.4.2 Water Quality

Water sensitive receivers within the vicinity of the project would include: salt water intakes, lagoons, coral and benthic communities and beaches.

Potential Impacts During Construction Phase The key water quality concern would be associated with the seabed disturbance during the construction phase. Dredging activities for bridge piers would inevitably result in the loss and re-suspension of sediment into the water column which would add to suspended sediment loads. The extent of the suspended sediment plume would depend on the rate of release, the working methods adopted, the particle size of the dredged material, settling velocity, prevailing currents and hydrodynamic conditions.

Sediment laden plumes may directly affect marine organisms through abrasion and clogging of fish gills and other organs or possibly result in reducing light penetration. Depending on sediment quality, dredging operations can give rise to


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concerns about possible release of nutrients or organically rich material which could result in oxygen depletion.

Other potential water quality impacts may result from:

• Construction site runoff

• Wastewater and sewage generated from construction activities and workforce

• Litter from packaging materials and waste construction materials

Mitigation Measures During Construction Phase In order to minimise water quality impacts, the following mitigation measures may be recommended. These include but are not limited to:

• Deployment of silt screens

• Mechanical grabs designed and maintained to avoid spillage

• Loading of barges and hoppers controlled to prevent splashing of dredged material to the surrounding water

• Excess material cleaned from decks and exposed areas before the vessel is moved

• Works not to cause foam, oil, grease, litter or other objection matter to be present in the water within and adjacent to the works site

In addition to standard good dredging practice, other good site practice to control construction site runoff, wastewater and sewage discharge from construction activities and workforce, and litter from packaging materials and waste construction materials, should be implemented.

Potential Impacts During Operational Phase Changes in hydraulic friction due to the bridge piers may lead to long-term impacts on the hydrodynamic and water quality conditions. The key issues potentially associated with this impact are as follows:

• Reduction or acceleration of tidal flows resulting in siltation or erosion of seabed (which may result in scour hole formation)

• Poorly flushed embayments

• Accumulation of floating debris

• Affect on coastal processes potentially leading to acceleration of erosion

• Adverse affect on the leisure quality of surfing on Surfers Beach

There would be no routine discharge of wastewater or contaminated surface drainage to sea surface watercourse in the operational phase. However, there would be road surface runoff that could be marginally contaminated from vehicles.

Mitigation Measures During Operational Phase In order to assess a potential long term impact on the hydrodynamic and water quality conditions, tidal flow simulations with and without the project are recommended. Longer spans and hydrodynamic shaping of the piers could be required if significant effects were observed.


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As a precautionary measure, proper drainage systems with silt traps and oil interceptors may be installed. Maintenance at regular intervals is recommended.

6.4.3 Air Quality

Air sensitive receivers within the vicinity of the project could include: domestic premises, hotels, hostels, hospitals, clinics, nurseries, temporary housing accommodation, school and educational institutes, offices, factories, shops, shopping centres, places of public worship, libraries, courts of law, sports stadiums and performing arts centres.

Potential Impacts During Construction Phase Most sections of the bridge are situated above marine water and adverse fugitive dust impact from marine-based construction is considered unlikely. However, construction located at the two landing sites would generate some fugitive dust with potential impacts on neighbouring sensitive receivers from various construction activities, including excavation, backfilling, transportation of materials, and wind erosion.

Mitigation Measures During Construction Phase In order to reduce the dust emission from the project the following mitigation measures may be recommended:

• Dusty material covered by impervious sheeting or sprayed with water

• The load of dusty materials on a vehicle leaving a construction site should be covered entirely by impervious sheeting

• High pressure vehicle washing facilities at exit points

• Stockpiled dusty material should not extend beyond the pedestrian barriers, fencing or traffic zones

Potential Impacts During Operational Phase During the operational phase, additional traffic would be generated with associated vehicular emissions. The associated air pollutants will be NO2 and RSP. Although the alignment of the three bridge options are primarily over the sea creating a buffer zone between the traffic on the bridge and the sensitive receivers the effects of traffic dispersal through the city streets also needs to be considered.

Mitigation Measures During Operational Phase As the ambient air quality results from [1] indicated that all parameters were within the WHO guidelines for ambient air quality, significant adverse air quality impacts from the proposed project are not anticipated. However, it is noted that promotion of buses on the bridge would reduce the emissions generated by additional traffic.

Air quality modelling combined with traffic studies is recommended to predict the impacts from increased road traffic.

6.4.4 Noise

Noise sensitive receivers within the vicinity of the project would include: residential and institutional uses, hospitals, medical clinics, homes for the aged, convalescent homes, places of worship, libraries, courts of law, performing arts centres, auditoria and amphitheatres, parks and hostels.


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Potential Impacts During Construction Phase

Construction activities would involve the use of Powered Mechanical Equipment

(PME) including air compressors, excavators, lorries, mobile cranes, concrete

lorry mixers, pokers, rollers, etc. Construction activities which may affect

neighbouring noise sensitive receivers would include:

• Operation of barge and dredger,

• Erecting cofferdam

• Building pile caps and piers

• Erecting concrete deck segments of the approach

• Installing the main bridge and side spans

At present it is not planned to use percussive pile driving due to the detrimental effects of the vibrations on the integrity of the carbonate deposits. Since this activity has a significant noise impact its omission is a positive reduction in the potential impacts.

Mitigation Measures During Construction Phase The following mitigation measures may be recommended:

• Good site practices to limit noise emissions at the source

• Use of quiet plant and working methods

• Use of site hoarding as noise barrier to screen noise at ground level NSRs

• Use of shrouds / temporary noise barriers to screen noise from relatively static PMEs

• Scheduling of construction works outside examination periods if necessary

Potential Impacts During Operational Phase As noted above, road traffic is likely to increase as a result of the project which has the potential to affect neighbouring sensitive receivers.

Mitigation Measures During Operational Phase If mitigation measures for road traffic noise are considered necessary the following could potentially be implemented:

• Strategic planning of alignment route

• Use of noise barriers

• Use of low noise surfacing materials

6.4.5 Summary

A preliminary environmental assessment regarding ecology, water quality, air quality and noise have been considered for the feasibility of a bridge between Malé and Hulhumalé. Relevant environmental legislations, guidelines, policies and environmental baseline information have been reviewed and collated. The key environmental impacts that may be caused by the construction and operation of the proposed road and bridge link have been identified and mitigation measures to address the potential impacts are recommended.


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The desk study indicates that destruction of the coral reef is likely to be the most significant environmental issue.

The design and construction of the bridge should seek to minimise the impact as far as practical. However, there will inevitably be some reef loss area and this may require measures to mitigate or compensate for the impact such as coral relocation and propagation measures and/or reef restoration/enhancement.

A second issue particular to Alignment Option A is that the bridge could impact the waves on Surfer’s Beach.

It should be noted that the assessment made within this report is preliminary in nature and mainly based on a desktop study. Should the project progress an Environmental Impact Assessment will be necessary and the project impacts will need to be re-evaluated based on site specific survey results as well as the updated design. Specific and applicable mitigation measures should be provided for implementation to minimize the impacts.

6.5 Influence of Climate Change

Climate change is leading to global sea level rise. The Maldives are particularly vulnerable to this effect since the elevation of the islands is typically less than two metres above sea level.

The sea level rise at the Maldives is approximately 0.5cm per year. In addition, there are seasonal fluctuations of around 20cm per year.

The vulnerability of the Maldives to sea level rise is largely outside the scope of the construction of a fixed link between the islands. However, Hulhumalé was built with a formation level 0.5m higher than Malé in order to provide greater resilience to sea level rise. The bridge, which will promote the development of Hulhumalé, will therefore be of some benefit to the climate change resilience of the nation.

The provision of a fixed link could also assist the nation in coping with some effects of sea level rise, specifically:

• Facilitating disaster relief efforts

• Aiding with population mobility in view of shifting land use patterns

A final point is that the detailing of the bridge landings should consider the future sea level rise and could perhaps be designed to allow for future dyke protection schemes.

Bridges between the islands could assist the nation in coping with some of the effects of sea level rise.


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7 Bridge Structure Options

7.1 Functional Cross Section

A significant influencing factor on the cost of the bridge is its width. Simply speaking, if the deck width is increased the cost will go up. Therefore the cross section of the bridge needs to be planned in terms of the functional provision (number of traffic lanes etc.). This essentially becomes a balance between cost and performance.

7.1.1 Carriageway

The minimum practical configuration for the bridge would be a single two lane carriageway with 1.0m wide hard strips which leads to an overall bridge width of 10.3m. One disadvantage of this minimum provision is that in the event of a vehicle breakdown on the bridge, the available width for traffic is severely restricted and there could be significant congestion.

Figure 34 Carriageway Option 1 – Minimum provision

A second option is to increase the hard strips to 2.0m wide and designate these as motorcycle lanes. This increases the traffic capacity of the bridge as well as provides for greater reliability of service since if a vehicle breaks down and pulls over to the side of the carriageway there is still space for traffic to pass. The overall bridge width is slightly increased to 12.3m.

Figure 35 Carriageway Option 2 – with motorcycle lanes

A third and final option which could be considered is a dual two lane carriageway with central divider. The overall width is significantly increased to 19.6m. Although this option provides for greater traffic capacity it comes at a significant cost penalty and it is unlikely that the traffic demand could justify this.


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Figure 36 Carriageway Option 3 – dual carriageway

For the purposes of this study, Option 2 has been assumed.

7.1.2 Utilities

In addition to carrying traffic, the bridge could carry utilities. By taking advantage of a fixed link to achieve multi-purpose objectives it is possible that the economic benefits of the project can be enhanced. Utilities which could be provided on the bridge include:

• Fresh water

• Sewerage

• Power

• Communications

At present each island has its own desalination plant for fresh water production. MWSC have indicated that it is operationally expensive to have distributed facilities and that they would like in the long term to consolidate production for the Greater Malé area, possibly using a facility in Gulhi Falhu.

A single production facility in Gulhi Falhu would require a fixed link between Malé and Villingili which is not the subject of this feasibility study but which it is understood is part of the long term development plan for Greater Malé.

However, in the medium term a water pipe on the bridge could still be of benefit. The present growth of water consumption in Malé is 15% per year and there is little space available to expand the facilities on the island. MWSC have a production facility on Hulhumalé and if it had a piped connection to Malé then expansion of this facility could meet the growing demand.

Another long term plan of MWSC is to introduce waste water treatment facilities. At present sewage is discharged approximately 200m offshore through a number of long sea outfalls. There is no space on Malé for waste water treatment so MWSC have a desire to pipe waste water to a centralised treatment facility, again possibly on Gulhi Falhu. There are more practical difficulties associated with piping sewage over long distances compared to fresh water and the cost-benefit ratio of providing for possible future installation of a sewerage pipe on the bridge would need to be carefully looked at.

A high voltage power cable could be provided on the bridge to connect together the power networks of Malé and Hulhumalé. This has the immediate benefit of building greater resilience into the system by allowing supply and demand balancing between the two population centres. In the longer term it would allow


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more flexibility in planning where new or improved facilities are provided when additional capacity is required.

There is an obvious benefit to having communications on the bridge (fibre-optic cables etc.).

7.1.3 Dedicated public transport provision

It is possible that the bridge could provide a dedicated public transport corridor. This could be in the form of a light rail system or guided busway. However, these options would come at a significant extra cost.

A better option would be to promote the use of buses on the bridge. This can easily be done through a toll structure which is favourable to buses.

Promoting bus operations would also provide employment opportunities to replace the workforce currently employed directly or indirectly by airport ferry operations.

7.1.4 Pedestrians

For Alignment Option A it is assumed that there would be no provision made for pedestrians on the bridge. The pedestrian usage of the bridge is expected to be very low considering the distance between points of interest either side of the bridge and would not justify the cost of the additional structural width required for footpaths.

For Alignment Option C it is assumed that footpaths would be provided on the section of the bridge between Malé Island and Funadhoo Island to facilitate access to any proposed developments on Funadhoo which would be within a comfortable walking distance. Whether or not footpaths should be provided on the longer section of the bridge between Funadhoo Island and Hulhulé Island depends upon future development plans and could be studied at the next stage.

7.2 Structural Options (Alignment Option A)

Based on the specific site conditions we have reviewed the suitability of different kind of bridge structures. The deep water at the site means that the cost of foundations will be relatively high and therefore the number of foundations should be minimised. This leads to the selection of long span structural options.

Sea crossing viaducts

Typically sea crossings in shallow water are built with constant depth continuous concrete viaducts with a span in the range of 50m to 75m.

This kind of construction is not suitable here due to the deep water which increases the costs of foundations.


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7.2.1 Options Selection

The shore to shore distance is approximately one kilometre which could be crossed in a single span, completely eliminating piers in the water. However, this would require a bridge with tall towers which would compromise the airport height restrictions.

Initially three different options were considered for the structural form:

Figure 37 Initial sketches of structural forms

A balanced cantilever beam bridge is a long span concrete box girder which could cross the channel with spans in the range of 180m to 230m. An extradosed bridge is a kind of a hybrid between a beam bridge and a cable stayed bridge. The achievable spans are similar to a beam bridge but the structural depth of the deck can be significantly reduced. The towers are relatively short and do not present an obstruction to aircraft.

The third alternative considered is a suspension bridge with a span of around 380m. This structural form can achieve a long span with relatively short towers and can reduce the number of piers in deep water. However, the superstructure cost is increased due to the suspension system and substantial anchor blocks are required to transfer the load from the main cables to the ground.

Further review of the site geology and bathymetry now appears to rule out the suspension bridge option. The highly variable characteristics of the carbonate deposits that form the barrier reef are unlikely to be suitable for the high bearing pressures required for the anchor block. Additional bathymetric data obtained has also revealed that the anchor block on Hulhulé Island would be located on a steep slope in deep water which would make the ground conditions even less favourable as well as making construction very difficult.

Therefore we have developed two fixed link structural options:

• Balanced cantilever beam bridge

• Extradosed bridge


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7.2.2 General Arrangement

The span arrangement of the bridge is dictated by the desire to keep the foundations away from sloped areas where it is anticipated that the carbonate deposits will in general exhibit poorer consolidation and increased likelihood of cavities. Essentially we wish to span over the sloping parts of the reef and locate the foundations either on the shallow reef flat or on the deep underwater plateau that forms the base of the lagoon.

This requires a span of approximately 220m to clear the reef slope on the south east corner of Malé Island and a span of approximately 140m to clear the steeper slope on Hulhulé Island. In the channel between the two reef slopes typical spans of 220m are adopted.

7.2.3 Foundation Construction

Without specific ground investigation data the assumptions made regarding foundation construction must be considered extremely preliminary.

We have assumed that the foundations will be direct footings bearing on the carbonate deposits. Unconsolidated granular deposits (coral sand) will be removed if present by airlifting and the base will be made approximately level by an underwater grab. Coring and grouting will be carried out to search for and fill in any dissolution features or cavities beneath the foundation. The formation will then be further levelled by tremmie concrete placed at the turn of the tide when currents are weaker. A precast concrete foundation will be sunk into position and levelled. Finally the precast foundation will be base grouted to provide good contact to the tremmie concrete formation.

At present we are assuming that a bearing capacity of approximately 200 kPa will be achievable by such procedures.

7.2.4 Balanced Cantilever Bridge Option

Refer to Drawings 217093/021 and 022 which are provided in Appendix A

The balanced cantilever bridge requires a deep girder at the piers to provide sufficient strength to resist the vertical loads on the bridge. A typical economic span to depth ratio is 18:1 with the practical engineering limit being approximately 20:1.

There are significant constraints to the depth of the girder introduced by the approach obstacle limitation surface at the airport and this has led to the following compromise situation at Pier E2:

• The bridge superstructure will be clear of MHHW but the soffit level is lower than the optimal level and the superstructure could be subject to wave actions in rough conditions

• The span to depth ratio is designed at the engineering limit of 20:1

• The clearance to the approach OLS has been reduced from the desirable 4.0m to 2.5m. Although the structure is below the OLS high sided vehicles could impinge on the edge of the OLS.

• The vertical gradient of the road exceeds the desirable maximum of 4.0%


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It should be noted that there will be a monolithic connection without bearings at Pier E2 which makes the situation with respect to wave action slightly better but nevertheless the above situation is not ideal.

Construction of the balanced cantilever superstructure will be either with in-situ travelling formwork or precast segments. The superstructure will be longitudinally prestressed.

Figure 38 Construction with travelling formwork (left) or precast segments (right)

In the shallow water at the western end of the bridge, it is likely to be more economical to construct a beam and slab deck bridge with shorter spans (around 30m to 40m). This also has a shallow structural depth which is advantageous in bringing the road level down to the low elevation of the island whilst still keeping clear of waves.

7.2.5 Extradosed Bridge Option

Refer to Drawings 217093/026 and 027 which are provided in Appendix A

The span arrangement of the extradosed bridge is identical to the balanced cantilever bridge but the extradosed bridge does not require such a deep girder at the pier since extra support is provided by the stay cables. This neatly solves all of the issues at Pier E2.

An extradosed bridge still has a relatively substantial girder and vertical loads are carried by a combination of beam action in the girder and support from the stay cables. This allows the towers to be relatively short compared to a cable stayed bridge which means that the airport height restrictions can be respected.

The stay cables will be multi-strand cables which consist of a number of individually galvanised and sheathed strands contained within an HPDE tube. A saddle will be provided in the towers using state of the art technology to achieve high performance with respect to fretting fatigue.

The tower of the extradosed bridge is visually striking and creates an opportunity for some aesthetic treatment in order to provide a more attractive structure. However, the structure should also respect engineering principles and the need for an economic solution.


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We have developed an elliptical tower form reminiscent of the reefs which are iconic to the Maldives. A number of alternatives could also be considered to select the most visually appropriate tower.

Figure 39 The iconic form of Maldivian reefs

7.3 Floating Bridge Option (Alignment C)

Refer to Drawings 217093/31 to 33 which are provided in Appendix A

A floating bridge option has been developed to examine whether this could lead to

a reduction in costs by eliminating the deepwater foundations.

Although floating bridges are not common, there are a number of existing examples in the world. Modern floating bridges can be divided into two types; pontoon girders where the bridge deck is a continuous floating box structure and pontoon foundations where the bridge deck spans between individual floating pontoon structures. The latter solution has become more prevalent and has the following advantages:

• Wave and current forces on the bridge are reduced

• Small vessels can navigate under the bridge

• The durability can be improved by keeping the deck clear of the water

We have developed a pontoon foundation solution. Steel truss girders span 100m between floating concrete pontoons. The pontoons have a recto-circular shape to reduce hydrodynamic forces and they are sized to ensure the bridge is stable against overturning.

The pontoons will require mooring cables to hold them in position. Two pontoon foundation bridges in Norway have been built without mooring cables in water depths exceeding 300 metres. The deck is curved and develops in-plan arch action to resist horizontal forces. However this relies on competent rock at the bridge abutments and the current speed and wave conditions at those bridge sites are not as severe as in this location. Therefore we have assumed a traditional mooring cable system.


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Each mooring cable will consist of a number of spiral strands in parallel. Redundancy will be built in so that the loss of any single strand does not endanger the structure.

Figure 40 Floating Pontoon Bridges in Norway

The complex bathymetry in the sloping regions of the reef together with the likely poor ground conditions mean that not all locations are suitable for anchoring mooring cables. Therefore some pontoons are not moored or are only partially moored. These pontoons will be held in position by the deck which is itself held in position by the pontoons which are fully moored.

7.4 Operation & Maintenance

The operation & maintenance activities fall into several different categories of activity:

Type of Activity Example Activities

Day to day operation of the bridge as a highway Collection of tolls etc.

Day to day visual inspections and routine maintenance

Replacement of lamps, cleaning of drainage etc.

Detailed inspections Annual inspection, principal inspection at six yearly intervals

Major maintenance that is required at regular intervals

Resurfacing etc.

Abnormal maintenance Replacement of bearings, expansion joints etc.

The day to day operation and maintenance of the bridge does not differ significantly between the different bridges. However, there are some important differences in the detailed inspection and major / abnormal maintenance activities.

As far as possible, the bridges will be designed and detailed to reduce inspection and maintenance requirements. For example, bearings will be replaced by monolithic connections where possible and intermediate expansion joints will be avoided as much as possible.

The durability design will need to take account of the marine climate and appropriate specifications will be required for materials and workmanship.


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Supervision of construction activities is also critical to ensuring that the as-built structure achieves the design intent with respect to quality and durability.

Design Life

The bridges will be designed, detailed and built for a design life of 100 to 120 years. This represents standard international practice and is longer than the design life of buildings due to the high capital cost and the critical importance of key infrastructure.

To specify a design life of 120 years does not imply demolition and replacement will be required after this time but after the end of the design life there will be an increasing risk over time that major rehabilition works will be required to keep the bridge in service.

Planning for a structure to achieve its design life means that the designer intends that the structure shall fulfil the design criteria throughout the period not that the structure shall remain unchanged. Furthermore, it should be recognised that some degree of maintenance and repair will be required for the structure to achieve its design life.

The balanced cantilever concrete beam bridge represents a very low maintenance solution. There are few structural components. All elements are concrete which generally requires less maintenance and all critical elements will be in compression which will limit cracking. The columns are in compression due to gravity loads and the deck is in compression due to prestress.

The extradosed bridge will require a slightly greater effort for inspection & maintenance. This is due to the introduction of stay cables which are high tension steel components provided with a multi-layer corrosion protection system. The integrity of the corrosion protection requires regular inspection. Furthermore the design life of stay cables will be around 50 years meaning that replacement of the stay cables during the design life of the structure is envisaged and this is a significant abnormal maintenance operation.

The floating bridge will require significantly more inspection & maintenance effort. There are two key issues, namely the steel superstructure and the mooring cables.

A steel superstructure has been introduced to make the bridge lighter and therefore able keep the size of the pontoons within reasonable limits. The use of steel in a marine environment requires regular inspection of the paint system and routine touch up maintenance. Furthermore, a complete replacement of the paint system will be required at approximately 20 to 25 year intervals representing a major maintenance operation. The steel deck also has fatigue critical welds which must be the subject of detailed inspections to ensure there is no fatigue crack propagation and these welds are in difficult to access areas on the underside of the bridge.

The mooring cables are high tension steel elements which are permanently submerged in salt water. The cables are connected to the pontoons below water level to avoid the highly corrosive splash zone environment but nevertheless entrained air in the water will lead to corrosion of the cables over time. They will require detailed inspection by divers at regular intervals to check for wire breaks and the design life of the cables will be approximately 15 to 20 years meaning that replacement will be required several times during the design life of the structure and this is a significant major maintenance operation.


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7.5 Appearance of the Bridge Options

An artistic image has been prepared showing how each option would appear from the roof terrace of the Hulhulé Island Hotel. This viewpoint was selected because it allows all options to be visualised from a single place and it gives a good idea of the scale of the bridge with respect to the surrounding landscape.

Further images have been prepared showing each option from a closer viewpoint set against an artificial background to give a better idea of the actual appearance of the bridge itself.

The artistic images are provided in Appendix B. Small scale reproductions of the close viewpoint images are provided below for ease of reference.

Figure 41 Appearance of the different bridge options

Balanced cantilever bridge on Alignment A

Extradosed bridge on Alignment A

Floating bridge on Alignment C


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8 Construction Cost Estimates

8.1 Methodology

There are generally two different methods available for estimating the construction cost of infrastructure projects:

• Top down estimate based on historic construction costs of similar projects calibrated or adjusted for features unique to the project

• Bottom up estimate based on detailed quantities of resources required for the construction and using market rates to evaluate the cost

Within the scope of this feasibility study a top down estimate has been carried out. For bridges, the cost of construction is normally considered in terms of the rate per square metre of deck area to allow a pro-rata comparison to be made of bridges of different lengths or widths but of similar materials and construction complexity.

There are no historic projects of a similar nature in the Maldives. Therefore historic construction costs for international projects need to be considered. The adjustments that need to be made for features unique to this project are:

• Construction in the Maldives where all materials need to be imported

• Construction in deep water with weak and uncertain ground

Although material costs are relatively high in the Maldives, labour costs are relatively low compared to the countries where suitable reference projects have been identified. This has been taken into account in the cost adjustment.

8.2 Fixed Bridge on Alignment A

The estimated construction cost of a fixed bridge on Alignment Option A at current prices is USD 70 million to USD 100 million. This is based on a unit rate of USD 5,250 to 7,500 per square metre for the main bridge and USD 1,750 to 2,500 per metre squared for the approach spans.

There is little difference between the balanced cantilever beam bridge and the extradosed bridge in terms of cost. The span configuration and foundation details are the same for both bridges with the only difference being the superstructure. Although this will have a cost implication, the difference will be relatively small and the span of 220m is in the range where both superstructure types are likely to be similar in cost. Therefore we have not differentiated between these two options in our cost estimates at this stage.

8.3 Floating Bridge on Alignment C

The floating bridge was initially proposed as an option which could reduce costs. However, after further study it is not clear that this would be a more economical option. Since this type of bridge is very rare in the world there are few reference projects that can be used as a basis for cost comparison. The closest example is the Bergsøysund Bridge in Norway which was built at a cost of USD 6,050 per square metre in current prices. It can be seen that this is within the range expected


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for the fixed bridge options. It is in fact possible that this bridge could actually be more expensive than a fixed bridge option because:

• The total length of the bridge is greater than the fixed bridge options.

• Although the foundations are not required, large concrete pontoons must still be constructed and a mooring system with anchorages is still required.

• The design current speeds and wave heights are more severe than for the Bergsøysund Bridge

• The superstructure must be made of steel rather than concrete in order to save weight. Therefore the cost of the superstructure will be higher than for the fixed bridge options.

At this stage we believe it would be prudent to assume that the cost of the floating bridge will be similar to the cost of the fixed bridge option and will be in the range of USD 70 million to USD 100 million.

Having said this, if the cost proves to be towards the lower end of our range of expectations and the cost of the fixed bridge proves to be towards the higher end then the floating bridge could still potentially prove to be an economical solution. There is simply insufficient data at this time to reliably determine which would be cheaper.

8.4 Operation & Maintenance Costs

Operation & maintenance costs are generally expressed as a percentage of the construction cost.

The average annual cost of bridge operation and maintenance in Western Europe, seen over the lifetime of a bridge, in relation to the construction cost is generally recognised to be in the range of 1 to 1.5%. For major bridges the recurrent cost is generally a lower percentage due to economies of scale, durable design, routine preventative maintenance and regular inspection.

The following annual operation and maintenance costs have been assumed considering the relative inspection and maintenance complexity:

• Balanced cantilever beam bridge 0.5%

• Extradosed bridge 1.0%

• Floating bridge 1.5%


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9 Potential Financing & Revenue Models

9.1 Alternatives for Financing the Bridge

Traditionally the provision of highway infrastructure is considered a public sector service and bridges and the like are financed through grants or funding supplied by the government.

However, in a growing number of cases private finance is being utilised for investment in highways and bridges.

The Strategic Action Plan of the government includes five priorities, one of which is Macroeconomic Reform to support private sector-led economic growth. It entails reducing the role of the state in the economy. A number of private finance projects have been initiated including of course the privatisation of Ibrahim Nasir International Airport and the government is experienced with, and keen to promote, private finance.

Considering the scale of this project, the capital expenditure requirement even when spread over several years, would be significant compared to current government expenditure. This makes the use of private finance particularly attractive.

Figure 42 Comparison between 2009 central government expenditure [3] and preliminary expenditure estimates for Male-Hulhumalé bridge spread over four years

9.1.1 Public Private Partnership

A Public Private Partnership would involve a contract between a public sector authority and a private party, in which the private party builds the bridge and assumes a degree of financial, technical and operational risk in the project. The degree of ownership between the public and private sectors would be negotiated as part of the concession agreement.

Malé-Hulhumalé Bridge

General public services

Defense

Education

Health

Social security and welfare

Housing and community amenities

Agriculture

Industry

Electricity, gas, and water

Transport and communications

Other economic services

Others


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In some types of PPP, the cost of providing the bridge would be borne exclusively by the users of the bridge and not by the taxpayer. In other types capital investment is made by the private entity on the strength of a contract with the government to provide agreed services and the cost of providing the service is borne wholly or in part by the government.

Government contributions to a PPP may also be in kind (notably the transfer of existing assets). The government may also provide a capital subsidy in the form of a one-time grant, or Viability Gap Funding, so as to make the project more attractive to the private investors. In some other cases, the government may support the project by providing revenue subsidies, including tax breaks and/or guaranteed annual revenues for a fixed period. (annuities).

The applicable type of PPP structure is based on the outcomes of detailed technical and financial studies. If the project is to seek private finance then a robust preliminary design and PPP structure needs to be developed to assure the prospective bidders that:

• The project is technically feasible

• The project is financially viable

• The project risks have been identified and are acceptable

At the same time, the preliminary design will define the project requirements to ensure that the government receives the required service levels and that the bridge itself is built to the required quality. The PPP structure and principles of bidding will also be developed to ensure the government achieves value for money.

It should be noted that the private sector will include risk in their cost estimations and therefore if unreasonable risk is transferred to the private sector the value for money will decline. An important part of preparing the project for bidding on a PPP basis is to comprehensively identify project risks, mitigate them where possible and then to provide an equitable sharing of risk between the government and the private partner with transfer of risk to the insurance sector as appropriate.

9.1.2 Development Aid

It is possible that the government could seek international aid to assist with financing the project. The scale of investment required exceeds the typical scale of multilateral aid to the Maldives. Although there are clear economic benefits to the bridge a robust case would need to be made to potential donors to demonstrate that the project should be supported. The key issues that are likely to be of interest to aid agencies include:

• Relief of urban congestion in Malé

• Improving accessibility and mobility of the local population for social and economic purposes and thereby increasing livelihoods

• Addressing urbanisation trends from the atolls to the Greater Malé region

• Climate change resilience

• Enhanced water security

For a project of this scale it is probable that multilateral agencies such as the Asian Development Bank or World Bank would be looking for co-finance from


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international governmental development agencies as well as for a portion of the financing to come from the Government of the Republic of Maldives.

To seek development aid for the project it is suggested that the government should initially reach out to potential donors to determine if there is any interest. It would be beneficial that preliminary technical and financial studies have been completed to provide indicative justification. If there is potential for development aid to be brought to the project then a detailed feasibility study would need to be carried out addressing the specific requirements of the donor agency. This is likely to require detailed economic and financial assessment of the project, environmental and social impact assessments as well as technical assessment.

The overall procurement time is likely to be significantly longer if development aid is used to part finance the project due to the increased levels of safeguards demanded by the aid sector as well as the greater number of interested parties which will inevitably prolong approval and tender evaluation periods.

9.1.3 Management, Operation & Maintenance Contract

If the construction of the project is financed by the public sector, possibly with the assistance of development aid, then it is still possible that a private partner could be introduced to manage the asset under a Management, Operation & Maintenance (MOM) contract.

Under a typical MOM contract, a private entity is given a seven year concession to operate and maintain the bridge. Toll revenue would be collected by the MOM contractor and this would pay for the concession.

The benefit of an MOM contract is that it would attract skilled international companies to manage the bridge since the skills and experience are unlikely to be available locally given that the Maldives have no existing major highway assets.

Although routine inspection and maintenance should be carried out by the concessionaire and paid for under the terms of the MOM contract, abnormal maintenance may still require additional government subsidy although the MOM contractor would implement the work.

9.2 Sources of Revenue

Discussion of sources of revenue depends upon whether one is considering revenue that could form part of a PPP structure for a private partner or alternatively revenue that the government could access to finance the project.

Assuming that the project was implemented on a PPP basis then revenue to the private partner could be based on:

• Direct user fees (tolls) which could comprise:

• Actual cash received at toll booths • Guaranteed minimum revenues to insure against low traffic volumes • Shadow tolling whereby the private partner is paid based on actual bridge

usage but the user is not charged (probably not applicable in this case)

• Payment of pre-agreed amounts independent of usage of the bridge (annuities)

• Payment in kind


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The following sources of revenue could also be considered although they would be comparatively small.

• Leasing of right of way for utilities

• Advertising

If the project is financed by the government then this is likely to require public sector borrowing which would have to be repaid over a number of years. This is in fact similar to payment of annuities to a private partner. In either case, revenue sources for the repayments include:

• Direct user fees (tolls)

• Indirect user fees (fuel taxes, vehicle taxes, excise duties)

• Specialised taxes based upon non-transportation activities but aimed at beneficiaries of the project (e.g. land and property value capture)

• General taxes which are used for broad purposes (e.g. income tax, property tax)

• Leasing of right of way for utilities

• Advertising

Tolls and Payment in Kind are sources of revenue that are of particular interest and which are discussed further below.

9.3 Tolls

A broad estimate has been made of the potential revenue that could be collected from tolling of the bridge. It must be emphasised that these estimates are indicative only and not based on detailed technical studies. The estimate has been based on the following factors:

• Willingness to pay based on current ferry charges and taking into account the premium that could be charged considering the greater convenience of the bridge

• Review of ferry schedules and load factors on the Malé to Hulhumalé ferry route

• Review of daily passenger demand on the Malé to Hulhulé ferry route

• Review of vehicle ownership in Malé

• Estimate of the number of person trips across the bridge per day based on a horizon year of 2020 assuming that Hulhumalé achieves its target population of 60,000.

• Consideration that many of the passenger trips will be by bus and that the toll charge is only one component of the cost of the journey. This means that the toll must be less than the estimated price that an individual is willing to pay for the trip

• Allowance for toll revenue generated by commercial goods vehicles

There are many unknowns in the above estimates and within the scope of this study a detailed financial forecast is not possible. The resulting estimates are:

• Estimated 8,000 to 12,000 passenger trips per day across the bridge


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• Estimated annual toll revenue of USD 2 to 5 million

The uncertainties have led to a very wide range in the estimated toll revenue. However, despite this, our preliminary analysis allows us to make the following tentative conclusions:

• Toll revenue is unlikely to be enough to finance the construction of the bridge

• Toll revenue may be sufficient to finance the operation and maintenance of the bridge on a commercially viable basis

Despite the insufficiency of the revenue to finance the construction on its own, it is still assumed that bridge will be a tolled facility for the following reasons:

• The revenue will still be beneficial for meeting the recurrent costs associated with the project.

• The revenue could be one component of a wider package in the development of an appropriate PPP structure

• An appropriate toll structure could be put in place to promote the use of buses to avoid that the bridge contributes to increased car ownership and congestion

It must be noted that if toll revenue is adopted within a private finance structure then the private entity will be interested to maximise revenue. This could represent a conflict of interest compared to the objective to adopt a toll structure that promotes public transport. This means that the toll fees which the private partner is allowed to charge must be very clearly set out in the PPP agreement together with adequate provision for price escalation etc.

Furthermore, robust traffic forecasts must be developed in order to assure the private partner that the actual toll revenue realised will be sufficient for their part in the project to be financially viable. This will require a clear understanding of which party bears the risk of the actual traffic being below expectations.

9.4 Payment in Kind

Considering that the toll revenue is unlikely to be able to finance the bridge, an option worthy of consideration is Payment in Kind.

This means that the government contributions to the project would include the transfer of an existing asset to the concessionaire. In theory that could be any asset with sufficient value to recompense the cost of construction of the bridge but in practice a politically acceptable solution is likely to require that the value of the asset is either connected to or enhanced by the project.

In this case, the obvious solution is to provide to the concessionaire land leases / development rights in Hulhumalé. The expectation is that the construction of the bridge will enhance the development potential of Hulhumalé and therefore increase the value of the land. This has a neat synergy and would appear to be a viable proposition.

The bridge will enhance the value of Hulhumalé and Payment in Kind can capture that to pay for the project


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This PPP model could not only be a means of financing the bridge, but could also kick start the next phase of development of Hulhumalé by introducing a private partner to the project. Specifically, it could be of interest to transfer to the concessionaire development rights to the first package of the Downtown Commercial Zone, possibly together with part of the adjacent Bayview Condominium District. The government could potentially derive returns from this approach through taxes charged on the rateable value of the developed land. These could also be used to offset the cost of the bridge.

The development of an appropriate payment in kind PPP model will require legal and financial analysis as well as urban planning to determine the most suitable development packages and leasing terms. However, as an order of magnitude calculation, based on current residential land sale prices in Hulhumalé a five hectare plot of land theoretically has a value of approximately USD 100 million. A cautious approach should be adopted to extrapolating land value in this way since the sale price achieved per square foot for a small parcel is not applicable to large areas of land. Nevertheless, this would suggest that financing the bridge either in part or in full based on payment in kind is at least feasible.

9.5 Conclusions

Based on government policy and current procurement trends in the Maldives it is believed that an appropriate PPP structure is likely to be the best way of financing the project.

The project is unlikely to be financially viable based solely on direct user fees (tolls). Therefore alternative financing and revenue strategies are required. It is likely that a successful strategy will combine the following elements:

• Private partner builds the bridge and then maintains and operates it for a fixed concession period (25 to 30 years)

• Initial government capital contribution in the form of Viability Gap Funding

• Additional Payment in Kind based on development rights / land leases for commercial / high value residential property in Hulhumalé

• Toll revenue collected by the private partner but respecting a pre-agreed toll structure which promotes public transport on the bridge

It is worth noting that the economic benefits of a project such as this frequently exceed the financial revenue that can be generated. This is because there are either long term benefits which are beyond the time frame of a private investor or because there are benefits which are associated with the project but for which a direct user charge cannot be applied.

In this case, the quality of life benefits achieved by reducing urban congestion in Malé and the enhanced climate change resilience by promoting development on slightly higher ground are both significant benefits for which direct charges to the beneficiaries cannot easily be applied. Therefore the fact that the project is not considered financially viable based on direct user fees should not be taken to mean that the project is not worthwhile.


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10 Comparison of Options

Bridge Option 1 - Balanced Cantilever 2 - Extradosed 3 - Floating Bridge

Appearance

Alignment Option Option A Option A Option C

Construction Cost USD 70M – 100M USD 70M – 100M USD 70M – 100M

Annual Operation &

Maintenance Cost

USD 0.35 – 0.50M USD 0.7M – 1.0M USD 1.0M – 1.5M

Key Design Issues Technical feasibility is

highly dependent on ground

conditions. Further study is

required to confirm

alignment and foundation

locations.

Possible wave action on

superstructure in rough

conditions

Technical feasibility is

highly dependent on ground

conditions. Further study is

required to confirm

alignment and foundation

locations.

Technical feasibility is

highly dependent on waves

and currents at the site.

Further study is required to

establish the feasibility.

Reef stability at Malé

landing point needs to be

considered.

Traffic Dispersal on Malé Very Good Very Good Poor

Future Connection to

Villingili

Direct Direct Indirect

Alignment Issues Vertical gradients exceed

desirable maximum

No special issues Indirect alignment will

increase travel time but

fringe benefit by connecting

to Funadhoo

Airport Operational Issues High sided vehicles will be

a transient obstacle at the

edge of the approach OLSe

No special issues No special issues

Navigation Issues Potential for

mast/deckhouse collision.

No special issues Bridge location is less

preferable for navigation

Environmental Issues Impact on leisure resources

(beaches)

Impact on leisure resources

(beaches)

No special issues

Serviceability in Adverse

Weather

Good Excellent Requires Investigation

Durability Good Good Acceptable


Issues

No special issues Requires greater technical

expertise for inspection &

maintenance

Requires greater technical

expertise for inspection &

maintenance

Mooring cables will require

regular inspection and

replacement

Each solution has advantages and disadvantages. At present it is not possible to conclusively recommend a preferred solution. Clearly Option 3 has a number of disadvantages and we would not recommend this option unless it proved to be cheaper. As noted in Section 10 there is insufficient data available to determine the relative costs of the different options which makes it difficult to eliminate Option 3 at this stage.


REP-217093-01 | Issue | 8 August 2011


11 ConclusionsFurther Study

All parties consulted were in favour of the construction of a fixMalé and Hulhumalé.

Construction of a bridge is feasible although there technical and financial challenges which must be overcome.

This Feasibility Study was envisaged as an initial scoping study and was liby the time as well as the information available. In view of the anticipated benefits of the project it is recommended that a carried out with the following objectives:

• Gather additional data

• Confirm technical details of

• Assess the impacts of the project

• Update cost estimates

• Develop procurement model for the project requirements

Figure 43 Possible procurement routes

During the Feasibility Study, three bridgepresent it is not possible Preliminary Design will be to further evaluate these options in order to more accurately define their technoas to the preferred option.

After the Preliminary Design, depending upon the procurement model adopted, the government can either appoint a consultant directly to carry out the detailed design (traditional Design

Detailed Design & Construction

Preliminary Design

Feasibility Study


Conclusions & Recommendations for Further Study

All parties consulted were in favour of the construction of a fixed link to connect

Construction of a bridge is feasible although there exist a number of significant and financial challenges which must be overcome.

tudy was envisaged as an initial scoping study and was liby the time as well as the information available. In view of the anticipated benefits of the project it is recommended that a Preliminary Design study is carried out with the following objectives:

Gather additional data

Confirm technical details of the project

Assess the impacts of the project

Update cost estimates

Develop procurement model for the project addressing the financial

Possible procurement routes

During the Feasibility Study, three bridge options have been developed. At present it is not possible to recommend one single solution. Therefore part of the Preliminary Design will be to further evaluate these options in order to more accurately define their techno-economic characteristics and to build a consensus as to the preferred option.

After the Preliminary Design, depending upon the procurement model adopted, the government can either appoint a consultant directly to carry out the detailed

(traditional Design-Bid-Build procurement) or else the project can be

Feasibility Study

Preliminary Design

Detailed Design

Construction Contract

Bid Process Management

Design and Build Tender

Design and Build Contract

PPP Tender

Concession Agreement


Page 65

for

ed link to connect

exist a number of significant

tudy was envisaged as an initial scoping study and was limited by the time as well as the information available. In view of the anticipated

study is

the financial

options have been developed. At recommend one single solution. Therefore part of the

Preliminary Design will be to further evaluate these options in order to more build a consensus

After the Preliminary Design, depending upon the procurement model adopted, the government can either appoint a consultant directly to carry out the detailed

r else the project can be

Project Preparation for Aid Agreement

Detailed Design

Construction Contract


REP-217093-01 | Issue | 8 August 2011


further developed under a Design & Build or PPP model. In the latter case, a Bid Process Management assignment will be required in order to develop the bid documents for the project including the Employer’s Requirements. In the case of a PPP model, the bid documents will need to include necessary financial, legal, traffic forecast, risk management data etc to show that the proposed PPP arrangement is commercially viable for the prospective tenderer. A final procurement option using international aid is likely to require an additional stage of project preparation prior to starting on detailed design.

An approximate timeline for the project for each of the procurement routes is given below. It is important to note that the overall procurement timeline is very dependent upon the duration required for decision making and project approvals. The duration anticipated for Preliminary Design itself is approximately 15 months which is mainly driven by the need to provide enough time for the offshore geotechnical investigation to be carried out and the results incorporated into the design. The 48 months assumed for construction is considered to be a relatively conservative estimate which could probably be reduced once the site conditions are more accurately determined.

Figure 44 Indicative procurement timeline

The specific tasks which are envisaged under the Preliminary Design are:

• Obtain validated and digitised copy of USF bathymetric data or carry out bathymetry survey of preferred bridge corridor(s)

• Topographic survey of bridge landing points

• Hydrological survey (waves and currents)

• Geotechnical investigation

• Survey of existing & proposed utilities


REP-217093-01 | Issue | 8 August 2011


• Conceptual design of bridge options and selection of preferred option

• Development of design criteria

• Marine risk assessment

• Traffic forecast and traffic impact assessment

• Environmental impact assessment

• Assessment of bridge impact on coastal processes

• Social impact assessment (e.g. ferry operations)

• Structural durability assessment

• Preliminary design of bridge

• Operation & maintenance plan

• Estimate of quantities of materials

• Land requirement plan

• Update of construction cost estimates

• Economic assessment

• Development of procurement approach and procurement schedule

• Financial assessment

If the preferred procurement route has already been identified at the beginning of Preliminary Design then the depth of detail of the tasks above could be tailored appropriately.

It would also be possible to slightly reduce the overall procurement timeline for the Design and Build / PPP procurement route by integrating the scope of works of the Bid Process Management into the Preliminary Design since this would allow prequalification to start earlier. The overall procurement time would then be similar to the traditional design-bid-build route where probably be red

In order to control costs at this early stage of project development it could be possible to subdivide the Preliminary Design into two stages with the aim to limit design and investigation costs in Stage 1:

• Stage 1 - Conceptual Design of options, update of cost estimates and selection of preferred option

• Stage 2 – Preliminary Design, assessment of impact, further update of cost estimates and development of procurement model

However, in order for the conceptual design to be meaningful some physical investigations and data gathering will be required and an appropriate scope for this stage could be developed.

References

GADL International Ltd Feasibility Study for Construction of a Bridge between Malé and Hulhumalé Final Report

REP-217093-01 | Issue 1 | 8 August 2011


[1] Aecom, Water Solutions, January 2011, Social and Environmental

Impact Assessment, Expansion and Modernisation of Malé

International Airport, GMR Malé International Airport

Private Limited, Maldives

[2] Admiralty Chart, 2005, Malé Atoll, United Kingdom Hydrographic

Office, Taunton, UK

[3] Asian Development Bank, Maldives Economic Data,[online] Available

at <http://www.adb.org/Documents/Books/Key_Indicators/2

010/pdf/MLD.pdf> [Accessed 30th June 2011]

[4] CDE Consulting, 2010, Hulhulé Island Airport Bathy Chart Harbour

Area, Maldives

[5] GMR Malé International Airport Private Limited, October 2010,

Rehabilitation, Expansion, Modernization, Operation and

Maintenance of Malé International Airport – Draft Master

Plan, Conditions Precedent to Effective Date in compliance

to Clause 6.2.1 Sub-clause (b) (ii) of the Concession

Agreement

[6] Kumarage, A. S., 2009, A Multi-Modal Public Transport System for

Malé, Maldives, 11th Conference on Competition and

Ownership in Land Passenger Transport, 20-25th September

2009, Delft University of Technology, Netherlands

[7] Japan International Cooperation Agency (JICA), December 1992, The

Development Study on the Seawall Construction Project for

Malé Island in the Republic of Maldives

[8] Larsen, O. D., 1993, Ship Collision with Bridges – The Interaction

between Vessel Traffic and Bridge Structures, IABSE

Structural Engineering Documents 4, Zurich, Switzerland

[9] Maldives Ports Limited, Port Information,[online] Available at

<http://www.port.com.mv/portinfo.aspx> [Accessed 30th

June 2011]

[10] MoEEW. (2007). National Adaptation Programme of Action (NAPA) -

Maldives. Ministry of Environment, Energy and Water, Malé,

Maldives

[11] MFR Géologie-Géotechnique SA, February 2009, Malé Reef Slope

Collapse Engineering Geology Assessment Phase 1, ERC

Environment Research Centre, Malé, Maldives

[12] Naar et al, 2009 [1], General Bathymetric Map of the Margins of Malé,

Maldives 1:5000, University of South Florida, USA

[13] Naar et al, 2009 [2], General Map With Classes of Similar Slope Angle

of the Margins of Malé, Maldives 1:5000, University of

South Florida, USA

Appendix A

Drawings

Drawn

Scale

Checked Approved

Date

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Rev Description Date

Printed by :

Drawing No.Drawing Title

Hong Kong Limited

Ove Arup & Partners

Consultant Client

GADL International Limited

Project

between Male and Hulhumale For Construction of a BridgeFeasibility Study

47

50

30

28

41

46

5

2

4243

43

43

43

43

43

43

38

47

45

45

46

28.520

20

50

44 44

45

42

40

52

35

3536

31

3.6

6.8

6.45.6

8.4

24

37 41

24

24

18.2

95

61

137

224

31.4

0.8

34

414047

50

8

2 3

5

106.4

4

30

30

8

20

154

16553

69

2030

2.6

2.6

20.9

5.1

51

30

40

51

42

30

0.7

4.2

11

24

16

3034

3.2

27

30

75

21650

22.5

27

35

31

5.5

12

21.5

10 2

0

30

B

C

C

A A

C

C

A

A

C

C

A

AB

B

B

C

A

A

C

A

AB

A

C

A

AB

ANCHORAGE

5.0

0.0

10.0

15.0

20.0

25.0

15 %

15 %

0.0

5.0

10.0

15.0

20.0

25.0

Tra

nsitio

nal surface (14.3

%)

Tra

nsitio

nal surface (14.3

%)

0.0

5.0

10.0

15.0

25.0

20.0

30.0

35.0

40.0

45.0 0.0

5.0

10.0

15.0

25.0

20.0

30.0

35.0

40.0

45.0

Tra

nsitio

nal Surface for

RW

Y C

ode N

um

ber 3,4; pre

cissio

n a

ppra

och (slo

pe: 14.4

%)

FIRST ISSUEA

Alignment Option- Overview

1:25000 on A3

OYK

N

217093/001

Option C

Option B

Notes:

(See note 4)Hulhumale Island

(See note 1)surfacesObstacle Limitation

OceanIndian

Runway 18

Runway 36

MC DM

Link Roadto HulhuteHulhumale

for detail217093/002Refer drawing

(See note 2)IslandFunadhoo

LagoonGulhi Falhu

IslandVillingili

Gaadhoo K

oa

IslandMale

07/11

AtollNorth Male

based on HDC masterplan.on Hulhumale Island are

4. Future developments shown

Island is to be relocated.storage facility on Funadhoo

3. It is assumed that the fuel

no. 3323.is based on Admiralty Chart

2. Seabed profile shown in plan

which is taken as +2.6mCD.measured from runway level (OLS) for the airport are

1. Obstacle limitation surfaces

satellite imagery has been reproduced under licence agreement and remains c Google.TM

@2007

layout shown)(Existing airport Hulhule Island

21/07/2011

08/11B OPTION A2 REMOVED

B

Option A

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

FP (optional)

5.0

0.0

10.0

15 %

15 %

0.0

5.0

10.0

Tra

nsitio

nal surface (14.3

%)

0.05.0

10.0

15.025.0

20.030.0

35.0

40.0

45.0

0.0

5.0

10.0

15.0

25.0

20.0

30.0

35.0

40.0

45.0

FIRST ISSUEA

DM

1:7000 on A3

OYK

- 217093/002

N

Alignment Option A,B and C

Option C

Option B

IslandFunadhoo

(See note 1)SurfaceObstacle Limitation

Runway 36

BeachSurfers

BeachArtificial

IslandMale

Gaadhoo K

oa

Tsunami Memorial

Notes: satellite imagery has been reproduced under licence agreement and remains c Google.TM

@2007

21/07/2011

07/11

based on HDC masterplan.on Hulhumale Island are

4. Future developments shown

Island is to be relocated.storage facility on Funadhoo

3. It is assumed that the fuel

data.is based on USF bathymetry

2. Seabed profile shown in plan

which is taken as +2.6mCD.measured from runway level (OLS) for the airport are

1. Obstacle limitation surfaces

B


Option A

Drawn

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Date

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40

35

3.6 6.8

6.4

5.6

8.424

18.2

2

35

10

11

24

16

30

34

3.2

Sheet 2 of 2

(Bala

nced C

antile

ver B

ox Gird

er)

General L

ayout o

f Brid

ge - O

ptio

n 1

0

50

60

-50

-1000+000 0+250 0+500 0+750 1+000 1+250 1+500

FIRST ISSUEA

DM

1:25000 on A3

-217093/021

AL

1:4000

Plan

1:4000

140m 220m 220m

Elevation

1:4000

140m220m 33m33m

Main BridgeApproach Approach

Navigation Channel

N

0+2

00

0+0

00

0+4

00

0+6

00

0+8

00

1+000

1+200

1+400

1+495

33m33m33m33m 33m33m33m

At Grade

Main Bridge

Approach

At Grade

Approach

Restriction Envelope

Airport Height

CH .79.0

CH .343.0

CH .1283.0

CH .1316.0

Notes:

CH .79.0

CH .343.0

CH .1283.0

CH .1316.0

Spread Foundation

Vertical Alignment Profile

Sheet 1 of 2

(Balanced Cantilever Box Girder)

General Layout of Bridge - Option 1

+1.2 M.H.H.W.

11

m

4.4

m

11

m

K 9.000

L 36.000m

G= 0.000%

PVI 0+020.0

00

Ele

v 2.6

00

G= 4.000%

PVI 0+105.0

00

Ele

v 6.0

00

L 40.000m

K 10.000

G= 0.000%

L 52.000m

K 13.000 PVI 0+813.0

00

Ele

v 2

8.4

49

G= -8.000%

L 100.000m

K 25.000

L 67.340m

K 13.000

PVI 1+255.0

99

Ele

v 6.2

81

G= -2.820%

PVI 1+385.6

24

Ele

v 2.6

00

G= 0.000%

K 13.000

L 36.660m

PVI 1+495.2

87

Ele

v 2.6

00

L 200.000m

K 25.000

Pier 0+343.0

09.6

5

Pier 0+483.0

015.2

5

Pier 0+703.0

024.0

5

Pier 0+923.0

024.0

5

Pier 1+143.0

014.7

5

(170m x 12m)

W2 W1 E1 E2

Hulhumale

headroom

2.5m min.

datum.metres above chart

2. All elevations are in

specified.metres unless otherwise

1. All dimensions are in

based on USF bathymetry data

Approximate Seabed Profile

Male

07/11

21/07/2011

G= 4.000%G= -4.000%

(Alignment option A)

C


= 887m sq.

by roundabout

Area occupied

= 887m sq.

by roundabout

Area occupied

08/11C ROUNDABOUTS ADDED

Drawn

Scale

Checked Approved

Date

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Sheet 2 of 2

(Bala

nced C

antile

ver B

ox Gird

er)

General L

ayout o

f Brid

ge - O

ptio

n 1

Sheet 2 of 2

(Bala

nced C

antile

ver B

ox Gird

er)

General L

ayout o

f Brid

ge - O

ptio

n 1

Sheet 2 of 2

(Bala

nced C

antile

ver B

ox Gird

er)

General L

ayout o

f Brid

ge - O

ptio

n 1

12.3m

5.2m

5m

3.5

m

15

1

1:100

Main Span Box Girder Cross Section

1:100

C BridgeL

C BridgeL

0.5m2m7.3m2m0.5m

4.4 @ C M

ain S

pan

11 @ S

upport F

ace of

Main S

pan

m

1.7

m

0.5m2m7.3m2m0.5m

12.3m

1:100

C BridgeL

U-BeamPrecast

SlabIn-situ

SurfacingBituminous

CarriagewayLane

MotorcycleLane

Motorcycle

LaneMotorcycle Carriageway

LaneMotorcycle

SurfacingBituminous

FallFall

Fall Fall

150

R

100

R

L

Approach Deck Typical Cross Section

1 - 1

19

m

38m1

m

C BridgeL

Main Span Pier Front Elevation

2 - 2

1:500

Closed chamber

Precast Spread FoundationSea Bed

2 2Min.

1 1

Sea Level

Access opening

C.J.

1:500

FIRST ISSUEA

A07/11

DM

1:500 on A3

-217093/022

AL 21/07/2011

Sheet 2 of 2

(Balanced Cantilever Box Girder)


Drawn

Scale

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Date

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40

35

3.6 6.8

6.4

5.6

8.424

18.2

2

35

10

11

24

16

30

34

3.2

B

C

A

A

C

A

A

B

A

C

A

A

B

A

A

C

A

C

C

+

0

50

60

-50

-1000+000 0+250 0+500 0+750 1+000 1+250 1+500

PVI 0+020.0

00

Ele

v 2.6

00

PVI 0+105.0

00

Ele

v 6.0

00

PVI 1+385.6

24

Ele

v 2.6

00

PVI 1+495.2

87

Ele

v 2.6

00

G= 0.000% G= 4.000% G= 0.000% G= 0.000%

K=9.000

K=10.000

K=13.000

FIRST ISSUEA

DM

1:4000 on A3

-

AL

1:4000

Elevation

1:4000

PVI 1+218.0

81

Ele

v 7.3

25

K=13.000

G= -2.820%

G= -4.000%G= 4.000%K=13.000

PVI 0+374.8

01

Ele

v 6.0

00

217093/026

4.4

m

1:4000

Plan

N

0+2

00

0+0

00

0+4

00

0+6

00

0+8

00

1+000

1+200

1+400

1+495

At Grade

Main Bridge

Approach

At Grade

Approach

140m 220m 220m 140m220m 33m33m

Main BridgeApproach Approach

33m33m33m33m 33m33m33m



Airport Height

Sheet 1 of 2

(Extradose)


+1.2 M.H.H.W.

PVI 0+813.0

00

Ele

v 2

3.5

28

L 200.000m

K 25.000

Navigation Channel

(170m x 12m)

W2 W1 E1 E2

Notes:

CH .79.0

CH .343.0

CH .1283.0

CH .1316.0

CH .79.0

Male

CH .343.0

CH .1283.0

CH .1316.0

Hulhumale

headroom

4.0m min.

datum.metres above chart

2. All elevations are in



07/11

21/07/2011


Approximate Seabed Profile Spread Foundation

C


(Alignment option A)

= 887m sq.

by roundabout

Area occupied

= 887m sq.

by roundabout

Area occupied

08/11C ROUNDABOUTS ADDED

Drawn

Scale

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Date

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1:100

Typical Deck Cross Section

LaneMotorcycle

SurfacingBituminous

CarriagewayLane

MotorcycleC BridgeL

Fall Fall

0.15m15.1m0.15m

2.1m

2.4m2.4m

4.4

m

1

2.29

1

1

Carriageway

0.5m3.5m2m 0.5m 3.5m 2m

1:100

1 - 1

CableStay

AnchorageCable

EndLive

Cable AnchorageTransverse Rib at

1m

2.6m

6.5

m20.4

m

3.4

m20.4

m

2.6m

5m

1m

0.1m

R

5m

5m

ElevationLow Tower side

2 - 2

Min.

Min.

1:500

C TowerL

1:500 1:500

C TowerL

1:500

High Tower Front Elevation

Seabed

Seabed

C.J.

LevelSea

LevelSea

LC Tower

C TowerL

2 2

1:500

1:500

High Tower Side Elevation

FIRST ISSUEA

A07/11

DM

1:500 on A3

-

AL 21/07/2011

217093/027

Sheet 2 of 2

(Extradose)


1.3m

Sea Level

openingAccess

Closed chamber

Precast Spread Foundation

5m

C TowerLWeb

Diaphragm

C BridgeL

4 - 4 3 - 3

4 4

3 3

38m

19

m

C BridgeL

C TowerL

11.3

m

17.6

m

LC Bridge

30

28

41

46

5

2

42

43

43

43

43

45

45

46

20

50

4542

52

18.2

2.6

2.6

20.9

5.1

40

51

42

30

27

30

B

C

C

A

A C

C

A

A

C

C

A

A

B

Drawn

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Date

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0+000

0+200

0+400

0+600

0+8

00

1+000

1+200

1+400

1+600

1+800

1+951

+

+

Plan

N

1:4000

FIRST ISSUEA

DM -

AL

A

217093/031

1:4000 on A3

At G

rade

Approach

Floating BridgeFloating Bridge

At

Gra

de

Approach

Appro

ach

At Grade

CH .41.0

CH .444.0

CH .576.0

CH .7

91.0

CH .8

24.0

CH .1

526.0

CH .1757.0

Notes:

Sheet 1 of 3

(Floating Bridge)


Funadhoo

(Alignment Option C)

chart.plan is based on admiralty

2. Seabed profile shown in



of Pontoon

Anchorage

Mooring Cables

Cables

Mooring

Hulhumale

21/07/2011

07/11

Male

Drawn

Scale

Checked Approved

Date

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Printed by :


Hong Kong Limited

Ove Arup & Partners

Consultant Client


Project


FIRST ISSUEA

DM -

AL

A

217093/032

1:4000 on A3

1:4000 1:4000

Elevation

1:4000

Elevation

1:4000

Approach

33m 33m 33m33m2-Span Module End ModuleEnd Module At GradeGradeAt

Approach

33m 33m33m5-Span Module End Module At GradeEnd Module 33m 33m33mAt Grade 33m 33m

50

0

-50

-1000+750 1+000 1+250 1+500 1+750 2+000

PVI 0+729.3

40

K=13.000

G= 4.000%

K=10.000

PVI 0+829.3

40

PVI 1+175.0

00

G= 0.000%

K=13.000

G= 4.000%

PVI 1+030.0

00

K=10.000

G= -4.000%

K=13.000

PVI 1+320.0

00

G= 0.000%

PVI 1+720.8

51

K=10.000

G= -4.000%

K=13.000

G= 0.000%

PVI 1+950.5

81

PVI 1+820.8

51

PVI 0+635.5

00

G= -4.000%

K=13.000

K=10.000

PVI 0+535.5

00

G= 0.000% G= 0.000%

K=10.000

PVI 0+129.9

56

G= 4.000%

K=13.000

PVI 0+000.0

00

PVI 0+029.9

56

G= 0.000%

Ele

v 2.6

00

Ele

v 6.6

00

Ele

v 2.6

00

Ele

v 6.6

00

Ele

v 2.6

00

Ele

v 2.6

00

Ele

v 6.6

00

Ele

v 6.6

00

Ele

v 1

2.4

00

Ele

v 6.6

00

Ele

v 6.6

00

Ele

v 2.6

00

Ele

v 2.6

00

100

50

100

0

-50

-1000+000 0+250 0+500



CH .4

1.0

CH .4

44.0

CH .5

76.0

CH .7

91.0

CH .8

24.0

CH .1

526.0

CH .1

757.0

Notes:


Airport Height

+0.6 M.S.L.

Sheet 2 of 3

(Floating Bridge)


Floating Bridge

Floating BridgeApproach

99.6m

Pontoon(70m x 8.5m)

Navigation Channel

Anchorage

Cable

Mooring

AnchorageCable

Mooring

Pontoon+0.6 M.S.L.

21/07/2011

07/11



above chart datum.2. All elevations are in metres

unless otherwise specified.1. All dimensions are in metres



Drawn

Scale

Checked Approved

Date

Filena

me :

J:\

217

093\

Arup\

CIVIL\

217

093-03

3.d

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Printed by :


Hong Kong Limited

Ove Arup & Partners

Consultant Client


Project


99.6m

100.3m

99.6m 99.6m

100.3m 100.3m

5m

LaneMotorcycleCarriageway

LaneMotorcycle

0.5m

2m7.3m2m

0.5m

12.9m

Fall Fall

SurfacingBituminous

stiffenerslongitudinal deck with Steel plate

at 4m centresSteel cross beam

Plan

1:500

1:1000

1:1000

Elevation

Plan

1:1000

Elevation

1:1000

Top plan bracing

concrete pontoon9-compartment

33m

8.8

m

1:100

Typical Deck Cross Section

1:500

1 - 1

1 1

Typical Section at Support

LC Pontoon LC PontoonLC Pontoon

LC Support LSupport CLC Support

Sea Level

Top plan bracing

LC PontoonLC Bearing

LBearing C

Varies

8.8

m

12.9m

Min.

moduleEnd

moduleEnd

2-Span Module (5-Span Module Similar)

End Span Module

Sea Level

SupportBearing

SupportBearing

7.4

m

C BridgeL

LC Pontoon

LL

L

LC Bridge

C Pontoon

column1m x 3m

C SupportC Support

6.45m6.45m

16.5m 16.5m

10.2

5m

10.2

5m

Deck and Pontoon at all supportsFixed connection between

Sheet 3 of 3

(Floating Bridge)


FIRST ISSUEA 07/11

DM

1:800 on A3

-

AL 21/07/2011

217093/033

Appendix B

Artistic Images

B

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Maldives - Male' hulhule bridge feasibility report August 2011 - Final

Government & Nonprofit

Transcript of Maldives - Male' hulhule bridge feasibility report August 2011 - Final