Bahrain World Trade Center

By:- DISHANT RAUTELA

Bahrain World Trade Center World trade centre, Bahrain (also called Bahrain WTC or BWTC It is a 240-metre-high (787 ft.), 50-floor, twin tower towers rising above a 3-storey podium

development adjacent to the Sheraton Hotel in the Commercial Business District of Manama, Bahrain.

It forms the focal point of a masterplan to rejuvenate an existing hotel and shopping mall. Rising to 240 metres in height, the twin office towers create a dramatic focal point visible throughout the Kingdom.

The towers were built in 2008.

INTRODUCTION

150 million dollar was required to built Bahrain World Trade Centre

It currently ranks as the second-tallest building in Bahrain, after the twin towers of the Bahrain Financial Harbour.

Tapering to a height of 240m, each tower is visually anchored to the ground by a concertina of curved, sail-like forms, and provides 34 floors of office space and an exclusive viewing deck on the 42nd floor.

Unique to this building and rising to the challenge of incorporating renewable energy solutions within sustainable architecture.

The design features three horizontal axis wind turbines mounted between the towers, taking advantage of the prevailing onshore wind to generate electricity,

the Bahrain World Trade Centre design includes three 29m diameter wind turbines horizontally supported on bridges.

The turbines are expected to produce between 11 and 15 percent of the total electrical consumption of the towers.

The towers were built in 2008 by the multi-national architectural firm Atkins.

Atkins was appointed to provide all master planning architecture and structural and MEP engineering design services for the Bahrain World Trade Centre site, located on the main King Faisal Highway in Manama, Bahrain.

More than half its area was previously developed, and comprised the Sheraton Bahrain Hotel, an associated single-storey luxury shopping mall, an office tower, car parking facilities, services and landscaped areas.

HISTORY

They developed the masterplan for the extended development that rejuvenates the existing mall and hotel and provides additional 50 storey twin office towers with unobstructed views over the Arabian Gulf.

Technical validation included computational fluid dynamics modelling, wind tunnel testing, vibration and acoustic assessments, electrical integration analysis and SARM analysis.

Bahrain is an island in the Persian Gulf and is exposed to wind flows that come across the Persian Gulf.

70% of the wind flow from the Persian Gulf comes directly onshore in Bahrain. This natural exposure to wind makes Bahrain an ideal location for energy generation from wind.

The WTC architects created a world’s structural first by atheistically incorporaeting commercial wind turbines into the fabric of the building.

CASE STUDYLOCATION

The Bahrain World Trade Center (also called Bahrain WTC or is located within the centre of the Kingdom’s Commercial Business District, Manama, with direct access off the King Faisal Highway.

The structure is constructed close to the King Faisal Highway, near popular landmarks such as the towers of Bahrain Financial Harbour (BFH), NBB and Abraj-Al-Lulu.

It currently ranks as the second-tallest building in Bahrain, after the twin towers of the Bahrain Financial Harbour.Its condinates are 26° 14′ 21″ N, 50° 34′ 53″ E

SOME NEARBY BUILDINGS

Bahrain Financial Harbour

Abraj-Al-Lulu

NBB Building

The towers were built in 2008 by the multi-national architectural firm Atkins. The original company, WS Atkins & Partners, was established by the late Sir William Atkins in 1938

with offices in Westminster in London.  It expanded rapidly after World War II into specialist services in town planning, engineering

sciences, architecture and project management. The company has been trading under the Atkins name since 2002. In 2009 Atkins was selected as the official engineering design services provider for the London

2012 Games. Some of their notable projects

ARCHITECTS

Hotel The Address Downtown The light house tower XIAN-INTERNATIONAL ARIPORTBURJ-AL-ARAB

KEY PLAN

Bus/Railway station distance Hospital distance Police station distance

Airport distance

SIZE The site has an area of 120000 sq. m. this area contains landscaping, office buildngs,

Anchor Tenant, Garden Court, Car Parking. The plan remodelled a hotel and a shopping mall in a prestigious area near the Arabian

Gulf.

Building, its parking and mall area is 88,617 sq.m.

Its floor area is 16,500 sq. m.

UPPER TURBINE -37th FLOOR

MIDDLE TURBINE- 27th FLOOR

LOWER TURBINE – 17th FLOOR

LENGTH OF EACH TOWER IS 68 m (APPROX) WIDTH OF TOWER IS 23 m (APPROX) LENGTH OF SITE IS 226 m. CONSIDERING WITH

SHOPPING MALL AND PARKING. WIDTH OF SITE IS 130 m. CONSIDERING WITH

SHOPPING MALL AND PARKING

NORTH FACE ELEVATION

In addition to the office towers, the development includes an extension to the existing retail mall, new restaurants and cafes, refurbishment of the adjacent 5-star hotel and 1,700 parking spaces.

The twin towers are framed predominantly in reinforced concrete, with structural steelwork used for the clad steel spire, panoramic lift enclosure and mezzanine floors.

There are 45 floors (excluding mezzanines) from the ground floor of the podium, as well as a 4.5 metre deep single storey basement.

Each tower has a separate continuous piled raft foundation at basement level.

The raft slabs vary in thickness according to loading and incorporate lift pits.

Beneath the main cores the raft thickness is 3.0 metres and the piles are 1200mm diameter, closely spaced

ORIENTATION World trade centre, oriented in such a way

that it face Arabian Gulf. The wind climate in the Arabian Gulf with its

dominant sea breeze characteristic is conducive to harnessing wind energy.

Its oriented by facing its turbines toward north – west direction, to get maximum wind flow.

From north-west direction it gets around 6.42 m/sec. to 11.2 m/sec wind speed

The authorities thought that it will get wind speed around 25m/sec, but in actual its half of it.

this air flow considered as S – flow.

This orientation provides 1,100 and 1,300 MWh per year and will provide for approximately 11% to 15% of the office towers’ electrical energy consumption.

We can see from figures that the part contains turbines receives maximum air flow, that due to S – streamline shape of building .

The blue part gets maximum air flow. When air flow is from true nort-west

CONCEPT

The concept design was inspired by the traditional Arabian “Wind Towers” and the shape of the sails of ships that use wind energy to surf in that the shape of the buildings harness the prevailing onshore breeze from the Gulf.

The two buildings that make up the complex are inspired by the shape of the sails of ships that use wind energy to surf like the WTC uses wind energy to supply the needs of the activities taking place inside it.

The project also aims to show the world that countries of the United Arab Emirates, known globally for its oil production, also have launched renewable energy.

Foundation • Each tower has a separate continuous piled raft foundation at basement level.

• The raft slabs vary in thickness according to loading and incorporate lift pits.

• Beneath the main cores the raft thickness is 3.0 metres and the piles are 1200mm diameter, closely spaced and rated at 18MN safe working load.

• Away from the main core the raft thickness reduces progressively to 2.0 metres and the piles to 1050mm diameter, more widely spaced and rated at 8MN safe working load.

• The loads acting on the pile group are predominantly dead loads, imposed loads and wind loads.

• These act in combination to generate maximum and minimum pile loads.

• Individual piles were modelled in the finite element analysis as vertical springs

BENDING MON+MENTS PER METRE LENGTH ANALYSIS FOR FOUNDATION

Primary structural system

The twin towers are in a ‘V’ formation, typically mirrored about their axis of symmetry.

The primary structure comprises main and secondary reinforced concrete cores, the main core consist housing lifts, escape stairs and toilets and secondary core housing an escape stair and electrical/telecoms rooms.

The floor plates typically consist storey height of 3.6 metres and are framed with reinforced vertical concrete columns on an 8.0m grid

PLAN OF A FLOOR SHOWING ELEMENTS

The wind load on the towers is resisted primarily by the main concrete core; secondary concrete core helps to relieve the main cores loads. The load transfer between the two cores occurs between the 20th and 24th floor levels.

The columns are positioned in a 26 ft grid pattern and the floor plates have a typical storey height of 12 ft.

The raking columns triangulate both of the cores providing the towers with a stiff framework. Due to the tapering shape of the towers, the secondary core terminates before reaching the highest office.

The panoramic core extends higher into the towers supporting the duplex offices and viewing gallery.

Above the gallery, lattice steelwork is used to structure the top clad section to help reduce weight.

The tapering shape of the towers also means that the center of gravity, center of mass, and center of stiffness vary on each floor, moving towards the panoramic lifts with increasing height.

The results of this may lead to dead load sway, however the possibility of that is very small because of the stiffening framework provided by the raking columns and the concentration of piles beneath the main core to reduce base rotation.

VERTICAL LOADS

The two towers are linked via three skybridges, each holding a 225kW wind turbine, totalling to 675 kW of wind power capacity.

Each turbines measure 29 m (95 ft) in diameter, and is aligned north-west, which is the direction from which air from the Persian Gulf blows in.

Bridges are of ovoid in shape. Three horizontal axis wind turbines have

been integrated into the building to generate electricity.

The fixed horizontal turbine suffers the drawback of only being able to operate with wind from a limited azimuth range - if problems with blade deflections and stressing through excessive skew flow are to be avoided.

Wind turbines and support bridges

OVOID SHAPE

CONCLUSIONThe Bahrain World Trade Centre is the world’s first large-scale integration of wind turbines into a building. This integration was one of the principal challenges on the project. The turbines were commissioned in April 2007, and global interest was received from environmental and architectural bodies, media and private institutions across the world. Other challenges on the project included the ‘fasttrack’ approach adopted for design and construction, the sheer scale and complexity of the project and the integration of the reinforced concrete, structural steelwork and cladding elements of the design. With their distinctive instantly recognisable design and utilisation of wind power, the twin towers are likely to become well known worldwide and contribute to developing Bahrain’s reputation as an appealing destination.

Design errorsUsing precise wind tunnel measurements and computer simulations on a model of the Bahrain WTC, Blocken calculated that the towers would actually produce 14 percent more wind energy if they were positioned the other way round. Or better still, suspending the wind turbines further back would have given a 31% higher energy output per year, Blocken discovered. Also if they build it facing north west direction, then it will get more power capacity. But that is no fair comparison, says the researcher. “Because of constructive and financial reasons this option isn’t realistic.”