4 Month Internship Report on Tunnel construction at Chickpet Metro Station

INTERNSHIP REPORT LOKESH C S

Dept. of Civil Engineering, K.V.G.C.E, Sullia, DK

CHAPTER 1

INTRODUCTION

1.1 ABOUT THE ORGANIZATION

Coastal Projects Limited (CPL) Established in the year 1995 and headquartered in

Hyderabad, leaving its foot prints and stepping forward in constructing the Nation’s

future, Coastal Projects Limited (CPL) is a well-established Construction company in

public sector, which has spread its wings in developing infrastructure all over the

country. Today, with its vast expertise, CPL has emerged as one of the pioneers and

specialists in the Underground Excavations covering all jobs of civil construction of

Tunnels for Underground Tubes and Underground Stations for Metro rails in difficult

Urban conditions; Underground Power House Complexes, Tunnels, Pump house and

Surge Pools for Hydro Power Projects in challenging geological conditions.

CPL is endowed with very efficient work force for tunnel construction in Irrigation

Projects and Railway Tunnels in arduous geological and geotechnical conditions of North

East sector. The Company’s success is driven by more than building some of the most

advanced facilities for its Clients. CPL is well known for its distinctive ability to

implement innovative project management techniques and to serve as a reliable provider

of knowledge-driven solutions for their complex construction projects. The Company has

complete and well equipped technical backup and suitably trained and specialized man

power in their respective fields and has been able to make commendable strides in its

chosen field of infrastructure.

The Company has executed contracts of well-established Corporations both in Private

and Public Sector and is well versed with the dynamics of project execution. With the

experience gained in the field of underground tunnelling, it has entered into joint ventures

with some of the leading companies and firms to take up prestigious Bangalore

Underground Metro Rail Projects, mega projects in power generation and irrigation to

expand its horizons



1.2 VISION OF THE ORGANIZATION

CPL team of construction professionals offers a single- source solution for all the

underground construction related needs. Efficient leaders, supported by experienced and

well trained technical staff which includes among others, Engineering personnel viz.

designers, planners, technicians and tradesmen, who are adept in handling the latest

equipment that facilitate in increasing productivity in underground tunnelling works, can

adopt themselves easily to the new technologies to achieve national and international

work standards.

1.3 MISSION OF THE ORGANIZATION

The missions of the organization are as follows:

Achieve work life balance in a challenging and rewarding environment

Deliver value with integrity and transparency.

Providing a conductive environment for employees to not just perform but to

consistently out-perform themselves by working on challenging projects.

To encourage the employees to stay abreast of the latest technologies and

continuously train them on latest technologies.

1.4 CORE VALUES OF THE ORGANIZATION

Coastal Projects Limited, make every moment of working career an unforgettable

experience

Coastal Projects has some core values

a. Quality They are driven to attend to clients concerns responsively towards

delivering commitments.

b. Innovative and creative: CPL is well known for its distinctive ability to

implement innovative project management techniques and to serve as a reliable

provider of knowledge-driven solutions for their complex construction projects.



c. Client values: The Company’s success is driven by more than building some of

the most advanced facilities for its Clients.

d. Employees: The Company pursues business opportunities that will enable them

to be competitive by empowering employees to take on initiative and at the same

time promote ownership of responsibilities and accountabilities to results and

performance.

1.5 QUALITY ASSURANCE OF THE ORGANIZATION

1.5.1 Quality Policy

Coastal Project Limited is committed to enhance customer satisfaction by customer

compliance to customer technical standards, reliability of services, adherence to time

schedule at competitive price through continual improvement and effective

implementation of Quality Management System. Coastal is also committed to provide

competitive and creative environment to its employees to achieve future goals of the

company.

1.5.2 Quality Objectives

The following are the quality objectives of GYT COASTAL-JV

The primary quality objective is to complete the project in accordance with

BMRCL requirements, within schedule, within budget and in conformance with

the Quality Assurance Manual and other required standards.

To successfully execute projects undertaken.

To describe the operational arrangements, resources and sequence/interaction

activities, which the JV will implement in order to provide adequate confidence of

meeting the contractual requirements for quality to the client BMRCL.

1.5.3 Quality Management System

To establish and maintain documentation quality system in orderly and understandable

manner and consistence with the requirements of ISO 9001:1994.Each basic element of



the quality system program, as defined in this project quality management plan, shall be

applied to all activities performed by GYT-Coastal JV and its sub-contractors/vendors.

1.6 ORGANIZATION AND MANAGEMENT

In every organization, the most important asset is the people that play essential role in the

performance of the company’s functions and responsibilities. Thus CPL has emerged as

one of the pioneers and specialists in the Underground Excavations covering all jobs of

civil construction of Tunnels for Underground Tubes and Underground Stations for

Metro rails in difficult urban conditions. The Bangalore Metro Rail Project has been

projected as one that will benefit everybody by its reduction in congestion, pollution and

increased mobility. CPL team of construction professionals offers a single- source

solution for all the underground construction related needs. The company has

organization and the employees, because of the mutual benefits that simultaneously being

enjoyed by, has grown tremendously and would like to be on the level where they should

be. Having confidence in the organization, they aim high.

1.7 PROJECT OVERVIEW

The Bangalore Metro Rail Project was proposed in 2002 and a special purpose vehicle,

the Bangalore Metro Rail Transit Limited (BMRTL) was formed to implement the Metro

Rail Project.

1.7.1 Majestic Metro Station

Bangalore (also Bengaluru) in the south west of India is the country's fastest-growing

metropolitan area. It seems to set to confirm a place as the third-largest city with a

population of well over five million and with more in surrounding satellite communities.

The state capital of Karnataka, Bangalore is a leading research Centre with a

concentration of the international information technology industry. An important location

for Indian Railways, Bangalore's urban transport has been made up of taxis, buses and

lightweight powered rickshaws. Coupled with the need to sustain the city's growth, the

social and economic transformation has focused official attention on developing rapid



high-volume rail-based public transport. Fig 1.1, 1.2 and 1.3 shows the logo, master plan of

Construction Contract of Underground Majestic Station (Interchange Station) for

Bangalore metro Rail Project Phase-1Bengaluru and Schematic route map for Majestic

metro respectively.

Fig 1.1 Logo of GYT Coastal JV

Guangdong Yuantian Engineering Company Limited (referred as GYT) is a first level

construction contractor of national water conservancy and hydropower engineering, a

subsidiary company of Guangdong construction engineering group corporation Ltd. GYT

was established in 2001. GYT has 7 first class national qualification and 5 second class

national qualification and has been awarded “Credit Enterprise of Guangdong Province”

for 18 years.

The interchange station at Majestic is an underground station where the two underground

segments of Purple and Green lines intersect each other approximately at 90°.The station

is designed around island platform configuration of 10m width each. The two platforms

are separated by a mezzanine in between to facilitate the interchange of passengers from

upper platform to lower platform and vice versa within the paid area without having to

cross the ticket gates. Through the entry structure at ground level, the passengers proceed

to the paid area of the concourse after passing through the gates.

From this level the passengers can go directly to the upper and lower platforms directly.

The ticket vending facilities are located at this level in the unpaid area. Over the station

box, office accommodation in eight storied structures have been planned with its

longitudinal axis parallel to the N-S direction, to facilitate natural lighting into the station

at upper platform level and mezzanine level. The station layout and the tunnels carrying



the tracks between the stations have governed the rail levels, which are 8mts for the

Purple Line and 20mts for the Green Line.

1.7.2 Station Construction

In Detailed works Program revision, have made a Grid wise plan of 20-25 m length and

have planned to progress from Zone E centre to all other directions of Zone A ,B,D and

for Zone C the works is planned to progress from East Contract boundary toward Zone E.

The schematic bifurcation of the Grid wise plan as an extract of the DWP for all Zones

with the completion dates of the activities have been mentioned for ready reference &

understanding.

The Purple Line of the Namma Metro is part of the metro rail system for the city

of Bangalore, India. The 18.22 km line connects Baiyyappanahalli to Mysore Road. The

line links the eastern, central and western areas of Bangalore. The Purple Line is mostly

elevated, with 12 elevated stations and 4 underground stations. The Majestic station

serves as the interchange station with the Green Line. It generally takes around 35

minutes to travel from one end to another end, as compared to around 90 minutes taken to

travel on road. There are 17 stations on the Purple Line. All underground stations were

built using the cut-and-cover method. Most underground stations are 300 meters long and

25 meters wide. The interchange station at Majestic is much larger.

The Green Line of the Namma Metro is part of the mass-transit rail system for the city

of Bangalore, India. It will consist of 25 stations from Nagasandra to Puttenahalli under

Phase I. When Phase II is completed, it will stretch from BIEC in the north to Anjanapura

in the south. The line will measure 24.20 km and will be mostly elevated, with some

stations underground. However, the stretch between Sampige Road to Kempegowda will

be opened to the public by August 2016. The southern stretch of the line will however be

operational by December 2016, thereby completing the entire Phase I project. There are

32 stations on the Green Line. 13 stations, from Nagasandra to Sampige Road are shown

in above.

https://en.wikipedia.org/wiki/Namma_Metro

https://en.wikipedia.org/wiki/Rapid_transit

https://en.wikipedia.org/wiki/Bangalore

https://en.wikipedia.org/wiki/India

https://en.wikipedia.org/wiki/Cut-and-cover

https://en.wikipedia.org/wiki/Namma_Metro

https://en.wikipedia.org/wiki/Bangalore

https://en.wikipedia.org/wiki/India



Fig 1.2 The Schematic Bifurcation of The Grid Wise Plan



Fig 1.3 Schematic route map for Majestic metro

1.7.3 Project partners of GYT Coastal-JV

The Company’s success is driven by more than building some of the most advanced

facilities for its Clients.

Client: Bangalore Metro Rail Corporation Ltd. (BMRCL). A joint venture of

government of Karnataka and government of India.

Contractors: Guangdong Yuantian Engineering co (GYT) & Coastal projects Ltd (CPL)

joint venture (JV).

General consultant: RITES-OC-PBI-SYSTRA

Detailed design consultant: Mott Mac Donald

1.7.4 Master plan of Underground Majestic Station (Interchange

Station)

Site Adress: Kempegowda Bus Station (KSRTC), Bengaluru



Fig 1.4 shows Master plan of Underground Majestic Station (Interchange Station).

Fig 1.4 Master plan of Underground Majestic Station (Interchange Station)

1.7.5 Site location map of Underground Majestic Station (Interchange

Station), Bengaluru

Fig 1.5 shows Site location map of Underground Majestic Station.

Fig 1.5 Site location map of Underground Majestic Station



1.7.6 Project Information of of Underground Majestic Station

(Interchange Station)

GYT-COASTAL JV:-The two parties have agreed to appoint GYT as lead partner of the

JOINT VENTURE for the performance of the contract and COASTAL as member

partner. The site layout is well planned with access to all the areas in the site and thus it

enhances the productivity. Steel yards are planned in such a way that minimum lead

distance is required.

Majestic station is the largest metro station in India. It has three levels with a total

surface area of 48,000 square metres (520,000 sq ft).

The station platform is 365 metres long for the Purple Line, and 300 metres long

for the Green Line.

The station's platforms are designed to handle 20,000 commuters at any given

time.

The upper level houses the ticket counters, the at-grade level is utilized by Purple

Line trains, and the underground level is utilized by Green Line trains.

The station has 12 staircases, 24 escalators, 18 emergency exits and 8 toilets.

The site is well secured with the following facilities.

Site is well secured with temporary compound wall from all sides.

Area is secured by Security guards and CCTV cameras.

Every vehicle and person entering site is recorded at the entrance.

The steel yard and scrap yard are constantly watched by a security.

Temporary facilities provided at the site.

Labor camps are inside site in order to save the transportation cost and time.

Site is well illuminated in the night.

Drinking water and toilets for labor is provided at the site.

Temporary access roads are provided to the site.

Transportation and accommodation facility is given to the workers.



Table 1.1 shows Project Information of Underground Majestic Station.

Table 1.1 Project Information of Underground Majestic Station

NAME OF THE WORK Construction Contract of Underground

Majestic Station (Interchange Station) for

Bangalore metro Rail Project Phase-1

LOCATION : Kempegowda Bus Station (KSRTC)

FUNDING : The Govt. of India

:The State Govt. of Karnataka

EMPLOYER : Bangalore Metro Rail Corporation Limited

ENGINEER : General Consultants to BMRCL - RITES-

PCI-PBI-SYSTRA

CONTRACTORS :GYT-COASTAL JV

CONTRACT VALUE : INR. 2,71,94,16,962.07 /

INR.2,96,24,18,778.75 (Variation-

01)/INR.3,13,21,40,378.61 (Variation-02)

CONTRACT AGT NO :BMR/UG/CONSTN/STN-MAJ DATED 18

SEP 2011

VALUE OF WORK 272 Crore

DATE OF COMMENCEMENT :16th

Dec 2011

EXPECTED COMPLETION DATE : 2016



1.7.7 Site layout of Underground Majestic Station (Interchange Station)

Fig 1.6 shows Site layout of Underground Majestic Station (Interchange Station).

Fig 1.6 Site layout of Underground Majestic Station (Interchange Station)



CHAPTER 2

ABOUT THE DEPARTMENT

2.1 SECTION OF THE COMPANY

The GYT-Coastal JV will ensure that all staff understand the importance of quality in

their work and accept the need to employ the working practices and procedures as

defined in the quality manual and the process procedure manual. All the working drawings

like structural drawing, sanitary drawing and electrical drawing are provided to the

respective sub-contractors based on the agreement (after the architectural drawing is selected

by the company) and then the project cost (bill of quantity) is calculated. Quality of the

organization is to describe the operational arrangements, resources and

sequence/interaction activities, which the JV will implement in order to provide

adequate confidence of meeting the contractual requirements for quality to the client

BMRCL. Fig 2.1 shows Organization Chart.

2.2 ROLES AND RESPONSIBILITIES

2.2.1 Management Representative

To ensure that the processes for quality management system are established,

implemented and maintained.

Conduct internal quality audits to assess the system performance and report it to

the top management.

Ensure awareness of customer requirements throughout the organization.

2.2.2 Roles of QA/QC Manager

The Quality Assurance Manager shall report to the Management Board.

Prepare, obtain approval, issue & implement quality assurance plan in compliance

with contract specifications & company requirements.

Be responsible for the interaction with the client, agencies, subcontractors and

internal departments on quality related matters.



Reports to the management as required.

Responsible for quality program implementation.

Carrying out inspection of outgoing construction activities at site.

Reports non-compliance and proposes remedial action to site staff and senior

management.

Responsible for conducting internal audit & report to management board.

Responsible for organizing third party external audits.

2.2.3 Roles of QA/QC Assistant Manager/Engineer

Report to the QA/QC Manager.

Responsible for material selection and mix combination to meet the specification

requirements within overall cost provisions.

Identifies all material requirements, sources.

Conducts qualification tests for source approval.

Conducts tests on materials.

Indents all laboratory equipment, commissions and conducts calibration exercises

as per plans.

Documents all tests in standard formats.

Conducts laboratory activities independently and reports any potential problems

to the higher authorities.

Follows up through remedial measures.

2.3 PLANT AND MACHINERY DEPARTMENT

Roles of Plant and Machinery in charge

• Report to Project Manager functionally.

• Co-ordinates with the Deputy Project Manager & Planning Engineer for daily

deployment of plant to various sections

• Conducts all preventive maintenance as per equipment manuals.



• Ensures adequate stock fast moving spares.

• Allots duty roaster to operators.

• Administrates fuel oil supply, reconciles usage in consultation with Stores

Department and submits reconciliation statements at the end of each month to

Billing and Planning Section.

• Conducts repairs, breakdown maintenance, arranges alternative equipment’s when

required economically.

2.3.1 Batching plant

Batching Plant is a device that combines various ingredients to form concrete. Some of

these inputs include sand, water, aggregates, fly ash, admixtures and cement. A Batching

Plant can have a variety of parts and accessories, including: mixers, cement batchers,

aggregate batchers, conveyors, radial stackers, aggregate bins, cement bins, heaters,

chillers, cement silos, batch plant controls and dust collectors. Fig 2.1 shows Batching

plant at the site

Fig 2.2 Batching plant at the site



Table 2.2 shows Total Machineries available at the site.

Table 2.2 Total Machineries available at the site

SI.

No Machinery Model/make

Total

Required

Available

at site

Balance

No’s

Required

1 Excavator/Rock breaker PC 300 4 4 0

2 Excavator PC 200 3 3 0

3 Long Stick & boom 19 m

2 2 0

4 Long Stick & boom 22 m

2 2 0

5 Dumper (10 cum cap)

6 6 0

6 Tractor Compressor for

Drilling/Blasting 3 3 0

7 Crawler 85 T cap Crane

1 1 0

8 Loader 3 Cum 1 1 0

9 Tower Crane fixed 2.9 Ton tip load - 55

mtr boom length 1 1 0

10 Tower Crane movable 2.9 Ton tip load - 55

mtr boom length 1 1 0

11 Batching Plant (60 cum/hr) 1 1 0

12 Batching Plant (Stand by) (30 cum/hr) 1 1 0

13 Concrete Boom Placer 35 Mtr length boom 1 1 0

14 Concrete Pump Stationery 30 Cum/Hr 1 1 0

15 Transit Mixer 7 Cum 6 6 0

16 Crawler Crane 100 T cap 1 1 0

17 Mobile Crane 80 T Cap 1 1 0

18 Mobile Crane 60 T Cap 1 1 0

19 Walk Behind roller 4T Cap 1 1 0

20 Plate Compactors

(Vibratory Hammer) 6 2 4

21 Concrete Bucket (Banana 1 cum 1 1 0



Bucket)

22 Compressor 400 cfm 1 1 0

23 Bar Cutting Machine

5 5 0

24 Bar Bending Machine

5 5 0

2.4 QUALITY DEPARTMENT IN THE COMPANY

To ensure the construction process of the works, which directly affect the quality, will be

executed under planned and controlled condition. The project manager is overall

responsible for implementation and supervising the construction work process. The

station manager will be responsible for all the construction activities at the site. The job

will be executing by a well experienced sub-contracting agency, the site engineer and

foreman of GYTC will directly supervise the work at the site and will be responsible for

controlling the day to day progress. The QC in charge is responsible for controlling the

inspection and testing activities.

2.4.1 Quality Implementation at Site

The maintenance of the quality of the work is the main objective of the company. The

company quality management system performs various activities to maintain the quality

of the work and materials. The quality manager ensures the quality of the site works and

respective materials that are procured at the site.

The GYT-Coastal JV will ensure that all staff understand the importance of quality in

their work and accept the need to employ the working practices and procedures as

defined in the quality manual and the process procedure manual.



2.4.2 Quality system structure and documentation

Figure 2.2 shows Documentation Structure at Site.

Fig 2.3 Documentation Structure at Site

2.5 QUALITY CONTROL TESTS CONDUCTED AT SITE

The quality management team ensures the verification of various materials purchased

from vendors by conducting respective tests according to the standard specification. The

various tests conducted in the site are as follows.

2.5.1 Consistency

To determine the quantity of water required to produce a cement paste of standard

Consistency.

The standard consistency of a cement paste is defined as that consistency which

will permit the vicat plunger to penetrate to a point 5 to 7 mm from the bottom of

the vicat mould.

For finding out initial setting time, final setting time, soundness of cement and

compressive strength of cement, it is necessary to fix the quantity of water to be

mixed in cement in each case. Requirements as per IS 269: 2015 Clause 7 (Table-

3) for OPC 53 Grade.



Result got when test conducted at the site is 27.4%

2.5.2 Slump Test

Slump test is the most widely used test in the field and laboratory which is used to check

the consistency of concrete used at a construction site. It provides useful information on

the uniformity in the day to day or even hour to hour production of concrete. The main

apparatus used for this test was 30cm height, 20cm bottom width and 10cm top width

cylindrical cone, 60cm tamping rod and iron plate. The workability depends on the

reversed gap between the cone and the fresh concrete after tamping and removing of the

cone.

The workability is classified as:

Very low when the height is 0 – 25mm

Low when the height is 25 – 50mm

Medium when the height is 50 – 100mm

The test result obtained for water cement ratio 0.5 is 80mm.

2.5.3 Compressive Strength Test

The purpose of the test is to determine the compressive strength of the concrete.

Procedure

Place the specimen in the machine and slowly bring the blocks to bear on the

specimen without shock until failure occurs.

Operate the machine at a constant rate within the range of 0.140 to 0.350 Mpa per

second.

Table 2.3 Compressive strength test results conducted at site

Sl

No.

Area of cube

(mm2)

Cube Testing

period (days)

Compressive strength (Mpa)

(Avg. of three results)

1 150 x 150 3 34

2 150 x 150 7 42.5

3 150 x 150 28 57



Fig 2.3 shows Compression Test Machine and Table 2.3 Compressive strength test results

conducted at site.

Fig 2.4 Compression test

2.5.4 Final test report on physical properties of cement

Fig 2.4 shows Final test report on physical properties of cement

Fig 2.5 Final test report on physical properties of cement



2.6 STORE & PURCHASE DEPARTMENT

Procedure followed by GYT-Coastal Projects Ltd

1. Preparation of requirement indent (purchase requisition)

Firstly a list of required items is listed out and then it shall be submitted to the indenter,

department heads and managers accordingly as shown in Fig.2.5 (which explains the

purchase requisition form used at the site). Then company will verify the same and sign

the purchase requisition.

Fig 2.6: Purchase requisition form that was used at the site

2. Quotation from seller (dealers)

The purchase requisition is then allowed to share with various sellers and accordingly

quotations are to be collected from them.

3. Selection of the best & lowest quotation

Quotation from various dealers is to be referred and out of which the best and economical

quotation is approved by the manager.

4. Quality assurance by the seller (dealer)

Here the seller checks the requirement accordingly and assures that he shall assure that he

shall provide the items of best quality as per the quotation.



5. Material issue challan & Register

After all the items are been received from the seller use of items on site a material issue

challan is to filled which shall be signed by approver, receiver & store keeper hence

accordingly the items are issued and brought into work. Different registers are maintained

with respect to its returnable policy i.e. diesel, survey instruments, tools etc. Fig 2.6

shows Material issue challan that was used at the site.

Fig 2.7 Material issue challan that was used at the site

2.7 SAFETY DEPARTMENT

Human life is irreplaceable, which is susceptible of minor infections. Nowadays it has

become common to hear accidents on the construction industry. The more the accidents

are becoming redundant the responsibility of the contractors and the attention to give to

safety of the workers is progressing to be paramount. Therefore, it cannot be denied to

work on increasing the safety condition of the site. The most effective way of avoiding

risks is the preventive strategy. As the health professionals use to say “prevention is

better than cure”, it is more than reasonable to be abide by such motto. Less concerned

safety rule, regulation and training are among the problem in the site.



Safety of all working staffs and visitors should be observed to a highest care. Infliction of

injury shall be minimized. For this prior readiness is very important. The safety

management will be carried out with a special superintendent to be assigned on site. The

superintendent will be assisted with a dresser to be employed for the site.

2.7.1 Health, Safety and Environmental Policy

Coastal Project Limited is committed is poised to achieve excellence in adoption of well-

established quality management system by a perpetual pursuit for perfection. Health and

safety of the work force employed, coupled with environmental protection is the foremost

priority of the company in the accomplishment of its goals and objectives.

2.7.2 Daily site safety inspection

Both the work site and safety supervisors are to conduct daily site safety inspection

around work activities and premises to ensure that work methods and the sites are

maintained to an acceptable standard.

2.7.3 Accident and Incident Investigation

GYT-COASTAL JV shall undertake detailed investigations into all accidents and

incidents including near misses to establish causes and prevent recurrence. A member of

the site Health and Safety Management team shall carry out such investigations that shall

identify the immediate and underlying causes. An investigation report shall be prepared

detailing remedial actions and sent to the client. GYT-COASTAL JV shall ensure that

health and safety information and statistics are communicated to client.

The four types of safety measures undertaken at sites, namely,

Personal Safety – here labours are educated about accidents that occur at work

environment and about the safety guards to be worn for a particular work and reduce the

risks.

Equipment Safety – Proper check, care and maintenance of any equipment used at the

site is taken up.



Environmental Safety – The working condition at the site to be healthy and pollution of

the site should be prevented using proper control measures.

Material Safety – only required amount of material for a particular work is permitted at

the site and wastage of the material is avoided.

Fig 2.8: Safety helmets

2.7.4 Safety Precautions at Site

The work should start daily at 8:00 hours

Child labour is strictly prohibited, Contractor should not be deploy under age

labours for work(under 18 years of age)

Children are not allowed in any construction area

PPEs should be worn by workers, supervisor and engineers.

Safe work procedures shall be strictly followed.

No work shall be carried out without the supervision of competent person

All accidents/incidents are to be reported safety department immediately.

Safety officers’ helmet Sub contractors’ helmet

Contractor’s helmet Client’s helmet



All electrically operated machines/ equipment's must be properly earthed.

Electrical repairs should be carried out by a qualified and authorized electrician.

Only trained and license holder operators are allowed to drive the vehicle and

equipment

Proper usage of tools and tackles during lifting operation at the site.

Spark / flame arrestor is to be fitted on gas cutting/welding equipment's.

Domestic LPG cylinders should not be used. Only industrial gas cylinders are

allowed at the site.

Work place should be maintained with good housekeeping and area should be

kept neat.

Uses of alcohol, drugs and smoking are strictly prohibited in the site.

Each day inspection was being done to check the safety working environment of

the site.

Lift and other openings were covered properly with reinforcement bars.

The contractors shall make in every work site, effective arrangements to provide

sufficient supply of drinking water with minimum quantity of 5 liters per

workman per day. Quantity of the drinking water shall confirm to the

requirements of national standards on public health,

Special instructions are given to the workers then and there. Example, if a person

is lifting a material, the entire load must be on the knees and legs and not on the

spinal cord.

The different permits required are

Height work permit

Confined space entry

Line breaking permit

Mobile crane operation permit

Each delivery of the material shall be visually inspected when delivered on the

site. The delivered materials shall be clean, homogeneous and free from debris,

root plant, and any other deleterious matter.

All contractors and sub-contractors employees shall comply with requirements of

the approved Health and Safety plan.



Workers shall carefully operate the hand tools, machines and all other

equipment’s and safety belt/safety harness shall be used by the workers, wherever

necessary.

Health and safety of the work force employed, coupled with environmental protection is

the foremost priority of the company in the accomplishment of its goals and objectives.

Fig 2.8 (a) and (b) shows safety precaution and sign board

Fig 2.9 (a) sign board Fig 2.9 (b) safety precaution



CHAPTER 3

TASKS PERFORMED

3.1 GENERAL

The internship training program at the site was controlling how the work is going on and

supervising the work based on the given check list which was given from the office. The

checklist for site supervisors is issued in order to ensure a uniform system of supervision

of building construction projects and as a result ensure the quality of construction. In the

checklist the responsibilities, liabilities and limitations of the supervisor are briefly

mentioned in the steps to the general terms.

Details of construction are specified in the drawings, technical specifications and in the

general and special conditions of the contract. The duty of site engineer was to ensure

that the construction works are executed in accordance with the contract requirement. In

the application of the checklist the details specified in the contract document always

precede before the application and use of it. There are also tables and forms in the

checklist that help as records of the incidences affecting the work and as references. In

addition the standard technical specification was used as reference on the preparation of

the checklist and shall always have precedence over the checklist. Therefore, most of the

internship program work was spent at site to become more familiar with site works and to

get more practical knowledge. Site work in general includes every kind of work executed

at the site starting from setting out till finishing works based on the given specification

and methodology. The site work that was observed in the four month internship period

was in the sub structure work and super structure work exclusively.

Any structure below the ground floor slab level including the basement, retaining walls,

ground slab, plinth beam and foundation is called a substructure. In most of the cases,

substructure work can be categorized as earthwork, concrete work and masonry work.

In the training program was about the various inspection works like reinforcement

checks, alignment checks and shuttering checks that has to be done before giving



clearance for concreting and the finishing works including mechanical, electrical and

plumbing (MEP) fittings. During this internship program it was possible to study about

the practical difficulties in working with conventional shuttering, manual concreting and

various machineries that is being used in the site. The entire internship program of four

months included study of both structural as well as finishing works. The structural works

included reinforcement, shuttering and concreting of footings, columns, beams and slabs

and also block work. The finishing works included plastering, fitting of electrical and

plumbing accessories. Any new staff joining the project shall attend SHE safety induction

training organized by GYTCOASTAL JV SHE officers/ Engineers in which all major

applicable SHE Rules and Regulations shall be highlighted. An attendance list of this

training will be filed in the safety department with the signature of each employee who

has attended the training programme. Fig 3.1 shows N-S platform level part plan block

work drawing

Fig 3.1: N-S platform level part plan block work drawing

3.2 VARIOUS TASKS PERFORMED AT THE SITE

3.2.1 Concrete Form Work

As fresh concrete is in plastic state when it is placed for construction purpose so, it

becomes necessary to provide some temporary structure to confine and support the

concrete till it gains sufficient strength for self-supporting. This temporary structure is



called form work. Concrete formwork serves as a mould to produce concrete elements

having a desired size and configuration. It is usually erected for this purpose and then

removed after the concrete has cured to a satisfactory strength. In some cases, concrete

forms may be left in place to become part of the permanent structure. For satisfactory

performance, formwork must be adequately strong and stiff to carry the loads produced

by the concrete, the workers placing and finishing the concrete, and any equipment or

materials supported by the forms. In the site the form work material used was plywood

material which has a good surface finish.

Plywood is used extensively for concrete forms and provides the following advantages:

It is economical in large panels.

It is available in various thicknesses.

It creates smooth, finished surfaces on concrete.

The general step used to construct a formwork in the site is:

Prepare the false works in the desired position and level.

Preparing the form work in a desired shape based on the drawing or the size of the

structure that is going to be cast.

Painting with a releasing agent if needed.

Nailing it with appropriate bracing element and false work.

One side of the wall formwork is first assembled ensuring that it is correctly aligned,

plumbed and strutted.

The steel reinforcement cage is then placed and positioned before the other side of the

formwork is erected and fixed.

Plywood sheet in combination with timber is the most common material used for wall

formwork.

To be rigid enough to confine plastic concrete at the lines grades and dimensions

indicated on the form plans without bulging or sagging under the load.

To be constructed as mortar tight as possible to prevent the loss of concrete

ingredients throughout the joints between the sections, and

To be easy to remove with minimal damage to the concrete surface.



Fig 3.2 (a) and (b) shows Form work carried out at the site.

(a) (b)

Fig 3.2 Form work carried out at the site

3.2.2 Reinforcement

Concrete is much weaker in tension than in compression. Its tensile strength is

approximately 10% of its compressive strength. Therefore, concrete is generally used in

conjunction with steel reinforcement, which provides the tensile strength in a concrete

member. The use of plain concrete without steel reinforcement is limited to pavements

and some slabs-on-ground. Steel is the ideal material to complement concrete because the

thermal expansion of both materials is the same. In other words, when heated or cooled,

both steel and concrete expand or contract equally and no stresses will be developed.

Fig 3.3 Reinforcement work for PCC



Steel also bonds well with concrete. In a composite material, the bond between two

materials is necessary for it to function as a single material. The bond between steel

and concrete is due to the chemistry of the two materials, which produces a chemical

bond between them. Additionally, as water from concrete evaporates, it shrinks and

grips the steel bars, making a mechanical bond. The mechanical bond is enhanced by

using reinforcing bars, or rebar, that have surface deformations. Because a mechanical

bond is a function of the area a contact between the two materials, surface

deformations increase that area, thereby increasing the bond. For the same reason,

rebar that have a light, firm layer of rut bonds better with concrete. Rust that is

produced by leaving rebar outdoors on a construction site for a few days or weeks is

not objectionable as long as the rust is not loose or flaky. Loose and flaky crust should

be scraped using burlap or a piece of cloth. Excessively rusted rebar should not be

used. Reinforcement grade of Fe 500 is extensively used in the project. Bars in the

range of 8mm to 32mm were used in the projects. Fig 3.3 and Fig 3.4 Reinforcement

work for PCC and Reinforcement work for the SVS shaft.

Fig 3.4 Reinforcement work for the SVS shaft

Before bulk purchase and transporting to the site they conduct tensile strength test from

the store, by taking sample from a place where they are intending to supply the material.

Such sampling will involve the consulting office and the result will be communicated.

When they receive approval, as it fulfils the expected minimum tensile strength, they

proceed to purchase the same. Place of deposit was made ready before its arrival on site



where it should be damped. A platform elevated from the top surface of the soil, that

would ensure the avoidance of minimum contact were prepared. Then placed there, and

was protected from any detrimental moisture, grease or oil or other substances that may

affect its quality. Shop drawing or bar schedule was produced by the Office Engineer, in

accordance to the structural design. This shop drawing or bar schedule was submitted to

the Resident Engineer and upon his approval mass production will be induced.

Bar bending workshop were situated in a place where it could be close to the site where

the bar is going to be placed in position. The bending of all types of reinforcement bars

was take place within the workshop. Except the column reinforcement bars all was tied

and placed in position exactly in a position where they are intended to be situated. Fig 3.5

(a) and (b) shows Storage of steel at the site

(a) (b)

Fig 3.5 Storage of steel at the site

On the sub-structure work hauling was performed by labour. But on the super structure it

is through the help of the mobile crane, that the required amount and type of

reinforcement bar will be conveyed. After placing in position of the reinforcement bar

and before the concrete pouring any dust particle was removed or cleaned. On horizontal

structures like the reinforced concrete in order to maintain the allowable concrete cover

depth or thickness concrete spacers was produced and cured and placed in position.



Fig 3.6 shows bar bending schedule for the SVS (Supply Ventilation Shaft)

Fig 3.6: Bar bending schedule for the SVS (Supply Ventilation Shaft)



Fig 3.7 shows the format of bar schedule working paper that was used at the site.

Fig 3.7: The format of bar schedule working paper that was used at the site.

3.2.3 Concreting

Concrete is a composite consisting of the dispersed phase of aggregates (ranging from its

maximum size coarse aggregates down to the fine sand particles) embedded in the matrix

of cement paste. This is a Portland cement concrete with the four constituents of Portland

cement, water, coarse aggregate and fine aggregate. These basic components remain in

current concrete but other constituents are now often added to modify its fresh and

hardened properties. This has broadened the scope in the design and construction of

concrete structures. It has also introduced factors that designers should recognize in order

to realize the desired performance in terms of structural adequacy, constructability and

required service life. These are translated into strength, workability and durability in



relation to properties of concrete. In addition, there is the need to satisfy these provisions

at the most cost effective price in practice. Since our building is a reinforced concrete

structure the concrete work was commenced every day for constructing/development of

every part of the building. The mix design for particular proportion will be designed and

proposed by the structural consultants. All relevant documents and specifications will

be available and tested before conducting the concreting work in the site. After the

satisfaction of the supervisor the work will be executed. Admixtures are additives that are

introduced in a concrete mix to modify the properties of concrete in its fresh and

hardened states. The amount of the admixture to be added varies in accordance to the

manufacturer’s specification. The proposed amount of the admixture will be added to the

concrete mix as dictated by the respective supervisor or site engineer.

Constituents of concrete

Cement: The cement used should be 43/53 grade ordinary Portland cement conforming

to IS 8112-1989, IS 12269-1897.

Water: The water that we are using should be free from materials that are deleterious to

the concrete and steel and should confirm to the requirements of IS 456-2000.

Fine aggregates: The aggregates should be clean, hard, dense and non-porous and should

satisfy the requirements of IS 383-1970, when tested in accordance to IS 2386 part 1 to 8.

The grading shall confirm to IS 383-1970.

Coarse aggregates: The aggregates should be clean, hard, dense and non-porous and

should satisfy the requirements of IS 383-1970, when tested in accordance to IS 2386

part 1 to 8. The grading shall confirm to IS 383-1970.

Admixtures: All the admixtures should confirm to IS 456-2000. The manufacturer test

certificate shall be furnished.

Reinforcement: The grade steel used in reinforcement concrete Fe 415/500 confirming

to IS 1786-2008 for TMT bars. The steel supplied with test certificate should be laid in

accordance with approved drawings.



Reinforcement and concrete work for PCC

Fig 3.8 (a) and (b) shows Reinforcement and concrete work for PCC

Fig 3.8 (a) concrete work for PCC Fig 3.8 (b) Reinforcement

Methodology

1. First properly compact the earth in the plinth. While compacting, care has to be

taken that a proper slope as required for the floor is provided.

2. Over this compacted earth filling, laid clean course sand of minimum thickness

100mm an over the sand layer a base concrete of grade M10 (1:3:6) in required

slope and tampered properly.

3. The thickness of base concrete is generally 50 mm.

4. Level the top of the base concrete and left it to set and harden for 24 hours

5. Then provide reinforcement above the concrete layer and the diameter of the bar

used for reinforcement is 8mm and 10mm.

Main bar of 10mm and distribution bar of 8mm @150 c/c.

6. After completion of the reinforcement laid cement concrete of grade M15 (1

cement: 2 sand: 4 coarse aggregate) of required thickness (say 100 mm).

7. Tamp the top surface thoroughly to compact it and use wooden floats to obtain a

smooth surface. The surface so obtained is cured for about 10 days before putting

it to use.



Mix Design: The mix design followed at the site is as follows. Table 3.1 and 3.2 shows

Mix Design followed at the site for M-sand and Mix Design followed at the site for river

sand

Table 3.1: Mix Design followed at the site for M-sand

Table 3.2: Mix Design followed at the site for river sand



Ready Mix Concrete placement method is as follows. Fig 3.9 (a) and (b) shows Transit

Truck

When transit truck arrived to the site, the concrete transport certificate was

checked for desired properties of concrete and time duration of transport.

Concrete was delivered to the site and discharged from the truck completely in the

form ready for vibration within hours after batching.

(a) (b)

Figure 3.9: Transit Truck

Concrete was placed in maximum 15 minutes after its arrival to the site, and the

finishing of placement would takes place before the cement starts setting.

Concrete was stored/ deposited as near as possible to its final position using crane

hoisted buckets, concrete pumps, chutes etc.,

If the concrete, due to transport, was segregated. It would be mixed again and

clean platforms, without adding water; if not the batch would be refused.

Concrete shall be placed to prevent segregation. The free fall of concrete should

in no case exceed 1.5m.

The concrete should be spread and deposited in horizontal uniform thick layers.

Concrete was then compacted using needle vibrators.

Concreting was continuously done to avoid planes of weakness.



Fig 3.10: (a) and (b) shows Flooring work carried out at the site and Table 3.3 Rate

Analysis for flooring work

(a) (b

Fig 3.10: Flooring work carried out at the site.

Table 3.3 Rate Analysis for flooring work

Sl

No.

Description Quantity(Cum) Rate (Rs) Amount (Rs)

1 Walk way North &

South

125.40 135 16929

2 U19 NS Plenum 111.37 135 15034.95

3 Plenum NS level 76.849 135 10334.115

4 U35S Panel room NS

level

61.372 135 8285.22

5 ASS 65.00 135 8775

6 Sewage Electric Room 15.412 135 2080.62

7 Store Room 27.750 135 3746.25

8 DB Room 25.445 135 3435.07

9 Plenum Room 3.840 135 518.4

10 Lift Room 25.994 135 3509.19

11 Escalator 37.406 135 5049.81

12 Passage 34.20 135 4617

Total 610.528 82422.63



3.2.4 Curing

The hydration reaction begins as soon as water and cement come into contact, but the rate

at which this reaction proceeds is extremely slow. It takes up to 6 months or longer for

concrete to gain its full strength. However, approximately 80% of concrete strength

develops in 28 days. Approximately two thirds of the 28-day strength is obtained in the

first 7 days and approximately half in the first 3 days. This is true only if sufficient water

and favorable temperature are available for the hydration reaction to continue. Providing

moisture to concrete continuously for hydration is called curing of concrete. Fig 3.11

shows curing work at the site.

(a) (b)

Fig 3.11 Curing Work at the Site

A well-cured concrete is denser and hence stronger and more durable. On construction

sites, curing is begun as soon as the concrete has fully set, which is generally 12 to 24

hours after placing the concrete. Curing in the initial stages of hardening is extremely

important and should continue as long as possible, not less than 7 days. It is the process

of preventing the loss of moisture from the concrete while maintaining a satisfactory

temperature regime.

Curing is essential for producing good concrete that has the desired strength,

impermeability and durability and is of particular importance in situations where the

water-cement ratio is low, or the cement has a high rate of strength development. So,



curing must be conducted using potable water and covering of the structural element

using covering material for at least 7 successive days to retain the moisture lost. In our

site curing of concrete starts from the finishing of the pouring and ends in a 7 days.

Mostly they cure at morning and evening time.

3.2.5 Block Work

Construction of solid blocks bonded together with mortar is termed as block masonry.

The strength of the block-work primarily depends upon quality and strength of the

blocks, type of mortar and the method of bonding adopted in construction. Mortar not

only acts as a cementing material but also imparts strength to the work by holding the

individual blocks together to act as a homogeneous mass. Mortar is usually a mixture of

cement and sand or lime and sand, or a mixture of three. The strength of the masonry also

depends on the nature of workmanship and supervision. Bad workmanship assisted by

lack of supervision may lead to unsound construction in spite of the materials used being

of the best possible type. Fig 3.12 shows Block manufacturing and storing location at the

site.

Fig 3.12 (a) Block manufacturing Fig 3.12 (b) storing location at the site

The general principles which should be observed for a sound block masonry construction

are given below.

The blocks used in a good work should be sound, hard and well burnt with uniform size,

shape and color. They should have no cracks or flaws and a fractured surface should be

free from holes, grit or lumps of lime etc.



The floor shall be cleaned for any dirt or unwanted materials.

The marking of the block wall shall be made with the proper supervision of the

Engineer using the respective drawings and specifications.

Concrete bed layer shall be laid and above which the first layer of the block will

be placed with proper spacing of mortar. The blocks should be slightly pressed

into the bed mortar while laying so as to ensure proper adhesion.

All the courses should be laid truly horizontal and all the vertical joints should be

truly vertical.

All the joints should be properly flushed and filled with 1:4 mortar so that no

cavity is left in between.

For every 2.5m of block work should provide the mulian column and for every

3m height should provide lintel.

The Mulian column is constructed using main bar of 10mm dia. and vertical stirrups of

8mm dia. Fig 3.13 shows Blocks work at the site

(a) (b)

Fig 3.13: Blocks work at the site

Half block partition walls should be reinforced with suitable reinforcement placed

at every third or fourth course of the block work. The reinforcement may be in

form of mild steel bars, flat bars, expanded mesh etc.,



All the finished masonry work should be kept wet for at least 7 days.

Plastering should be done after about 28 days of completion of block masonry.

This permits adequate time for the shrinkage in masonry and concrete to take

place before plastering operation is carried out.

The marking and chipping of electrical and plumbing conduits will be done before

the plastering operation.

Different sizes of solid blocks available at site

400mm x 200mm x 150mm

400mm x 200mm x 100mm

Test for Solid blocks

Dimension test

Compression test

Absorption test

3.2.6 Plastering

This is a process of covering rough surfaces with a plastic material to obtain an even,

smooth, regular, clean and durable surface. Plastering conceals defective workmanship

and covers up unsound and cheap quality material. Plastering is required to provide a

satisfactory base for decorating the surface by white-washing, color washing, painting.

The plaster is made by working together a mixture of building materials which may be

cement, lime or clay, fine aggregates and water. Fine sand is often recommended for

plastering and it should be so graded that it does not pass by more than 5% through a

sieve. Sand used should be clean, sharp and free from deleterious matter.

Preparation of the surface for plastering

The durability of the plaster depends to a great extent upon its adhesion with the

block masonry. The preparation of surface for plastering is therefore of prime

importance.



All the projections which extend by more than 30mm from the general surface of

the masonry wall face are knocked off to obtain surface and this also helps to

reduce consumption of plaster.

In order to obtain a good key for the plaster with the wall surface, all the joints in

the masonry are raked out for depth of at least 13mm.

Dust or loose mortar is brushed out of the raked joints. The surface is rendered

free from oily/greasy spots.

The surface is thoroughly washed with water and kept wet before paltering is

commenced. Fig 3.14 shows Interior and exterior plastering work.

Fig 3.14 (a): Interior and exterior plastering work.

Fig 3.14 (b): Interior and exterior plastering work.



To ensure required thickness and a true surface, bull mark of plaster are first of all

applied horizontally and vertically at about 1.8m apart over the entire surface.

This surface patches of plaster serves as gauges for maintain even thickness of the

plaster being applied.

Mortar is then applied on the wall between the screed and trowel.

Table 3.4: Details of plastering.

3.2.7 Painting

Plastering wall should be free from dust and it should be in dry condition

To apply two coat wall putty, after 6 to 8 hours lightly scrub the wall and apply

primer.

Mixing proportion of primer :for 1 liter primer add 40% of water

After applying of primer to start the painting works with tools of rollers or

brusher.

Painting mixing proportion is maintained at the site is 1 liter paint adding 40% of

water.

Texture paint

Apply direct to plaster wall only skilled labour are required.

Then apply weather coat paint (primer not required)

3.2.8 Granite work

It is recommended that the slabs going to be laid are free and clear of all dust and debris.

It is vital to enable a good bond to take place between mortar and the concrete/ adhesive

base.

Plastering Ratio Thickness

Internal Plastering 1:4 12mm

External Plastering 1:4 18mm



Mortar compound- Recommended mix is 1:4 cement mortar mix.

Water to be added for the desired consistency.

Granite size and thickness will be varied. Normally 900mm x 1200mm and thickness of

12mm to 20mm is used. Fig 3.15 shows Granite work in the platform level

Fig 3.15 Granite work in the platform level

Laying method

Clean and dampen the concrete on which the stones are to be laid.

Apply the mortar coat in an even mix of 40 – 50mm thick.

Place the granite into position by gently tapping down with a rubber mallet. It is

important to ensure that there are no air voids under the product as this may cause

the adhesion of granite to fail.

Tap the granite stone down to the desired level.

Remove all excess material from the surface of the granite stone using a clean

sponge with clean water. This is very much essential to protect the stone surface

from getting scratched.

Also do not spread excess mortar as it may begin to dry before you have laid the

stone.

3.2.9 Labour details

Depending up on the quantity of work done and the availability of labour for different

works number of labours required will be different and labour payment is also done as

per the quantity and quality of particular work.



Table 3.5 and 3.6 shows Majestic man power requirement and Labour rates respectively.

Table 3.5: Majestic man power requirement

Month

Bar benders/

Helpers

(No’s)

Carpenter/

Helpers

(No’s)

Masons/

Helpers

(No’s)

Unskilled

(No’s)

TOTAL

(No’s)

Aug-14 120 175 125 110 530

Sep-14 128 189 145 120 582

Oct-14 147 266 178 125 716

Nov-14 168 345 215 100 828

Dec-14 188 403 288 100 978

Jan-15 178 398 250 100 926

Feb-15 190 389 236 110 925

Mar-15 185 375 253 110 923

Apr-15 175 372 245 110 902

May-15 178 365 239 110 892

Jun-15 174 373 248 100 895

Jul-15 168 361 258 100 886

Aug-15 113 243 173 100 630

Sep-15 110 198 112 100 520

Oct-15 97 208 148 100 553

Nov-15 59 127 91 100 378

Dec-15 29 208 44 112 393

Jan-16 21 155 90 108 374

Feb-16 25 145 87 110 367

Mar-16 24 140 92 107 363

Apr-16 25 142 95 102 364

May-16 24 138 93 105 360

Jun-16 22 135 78 110 345

Jul-16 21 132 73 108 334

Aug-16 22 135 72 105 334

Sep-16 22 133 71 109 335

Oct-16 20 128 68 122 338



Labour Rates

Table 3.6: Labour rates

Labour Unit Rate

General supervisor 1No Rs. 600

General mason 1No Rs. 600

General male helper 1No Rs. 400

Carpenter 1No Rs. 600

Carpentry helper 1No Rs. 400

Bar bender 1No Rs. 600

Bar bender helper 1No Rs. 400

3.3 TUNNELLING

3.3.1 GENERAL

A tunnel is an underground or underwater passageway, dig through the surrounding

soil/earth/rock and enclosed except for entrance and exit, commonly at each end. A

pipeline is not a tunnel, though some recent tunnels have used immersed tube

construction techniques rather than traditional tunnel boring methods.

The underground tunnel boring method using conventional means (known as NATM

method or New Austrian Tunnelling Method) is the second (in terms of preference)

construction method applied internationally for the construction of tunnels using the

underground boring method. The Tunnel Boring Machine (ΤΒΜ) is the method, which is

preferably used for the construction of tunnels. In urban areas where Metropolitan

Railways (Metro) are constructed, it is important not to disturb the functions of the city

even if this implies increase in the financial cost of the projects.



Fig 3.16 shows Cross-section of Bangalore Metro Underground Tunnel

Fig 3.16 Cross-section of Bangalore Metro Underground Tunnel

Before the Tunnel Construction

Survey of the area

Piling

Excavation

Installation of the tunneling machine.

3.3.2 TUNNEL SPECIFICATIONS

Depth below ground level : 15 to 18m

Type of tunnels : twin tunnels, one for each track

Distance Centre to Centre

Of tunnels : 15.04m

Diameter (clear inside) : 5.60m

Bore diameter : 6.44m

Concrete lining thickness : 280mm

Tunnel construction by : 1.Slurry TBM

2. Earth Pressure Balanced Machine (EPBM)



Table 3.7 shows Tunnel rings requirement for the different stations

Table 3.7 Tunnel rings requirement for the different stations

Location Total Length (m) No. of rings

South Bound

North Ramp to Majestic North Shaft 953 635

Majestic South Shaft to Chickpet Station 745 497

Chickpet Station to City Market Station 432 288

City Market Station to South Ramp 391 261

North Bound

North Ramp to Majestic North Shaft 973 649

Majestic South Shaft to Chickpet Station 745 497

Chickpet Station to City Market Station 432 288

City Market Station to South Ramp 391 261

Total 5062 3374

The ring consists of 5 segments and a key to complete a ring.

Tunnel contains series of the rings bound together to form a frame of the

tunnel.

The key position is decided by the TBM to make it easy to take it out.

Primary grouting is done by the automated TBM grout to arrest the water

table.

If still the water seepage is observed the secondary and third level of grouting

can be done.

With a capacity of 11m per day, Helen and Margarita are the two drilling

machines (Tunnel Boring Machines, TBM) used for tunneling this section.

The earth pressure balanced TBM method has been employed for tunneling

using slurry TBM, while the cut and cover method facilitated the station



3.3.3 Ring Specification

Width of ring is 1.5m

Key segment is comparatively smaller portion compared to others.

Key is inserted at the last.

The Bolt and Nut connections are provided to hold segments together.

Joint between two segment is known as LIP

Joint between two ring is known as STEP

Weight of each ring is 19.1 ton.

3.3.4 Materials used for Segment construction

Steel reinforcement: HYSD Reinforcement bars of grade Fe 500 will conform to

IS1786: 1985.

Concrete: Concrete of M50 grade as per detailed design drawing and approved. Mix.

Design conforming to IS 456:2000 will be used

.Water: Clean water will be used in preparing concrete which is free from solid

suspended matter and organic particles and will meet the requirements of IS 456 -2000.

Each ring is formed by assembling 6 different types of segments namely

Table 3.7 shows Different types of segments to form tunnel ring. Fig 3.17 shows Method

of Stacking for segments at the site

Table 3.7: Different types of segments to form tunnel ring.

A1 B1 C1 D1 E1 K1

A2 B2 C2 D2 E2 K2

- - - - - -

A8 B8 C8 D3 E8 K8



Method of Stacking for segments.

Fig 3.17 Method of Stacking for segments at the site

3.3.5 TUNNEL BORING MACHINE

Excavation of tunnels housing various projects is taken up using Tunnel boring

machines (TBM). Unlike the previous method of excavating tunnels using drilling

and blasting (D and B) method, TBM method is said to have been more scientific

and advanced. It works with the electrical supply of 11kv produced.

Tunnel boring machine is 90 m in length more or less depended on the process of

muck out.

TBMs can bore through hard rock, sand and almost any variety of soil and rock

structure beneath the earth’s crust. The diameters of tunnels excavated through

TBMs range from a mere One meter to 16 meters.

TBMs are widely used in high density urban areas. One machine can drill an

average 20m a day on normal soil and 12m on rocky soil.

The excavation in the UG North-South corridor of Bangalore metro must be realized with

a TBM capable of applying a counter-pressure at the face. Two types of systems are

currently available.



Fig 3.18 shows Tunnel boring machine

Fig 3.18 Tunnel boring machine

1. Earth Pressure Balance (EPS) system

2. Slurry Shield (SS) system.

A wide explanation about these two types of machines is reported as Mechanized

tunnelling in urban areas' edited by Taylor & Francis. In brief for the UG - North-South

corridor, the following considerations shall be done from a technical point of view:

1. The grain size distribution of the soils in Bangalore is more fitting with the natural

curve of application of a SS but with adequate ground treatment an EPB shall

have the same results as a SS;

2. Considering that a relevant part of the line will, be excavated in the weathered

granite where it is possible to find boulders floating in the residual soils. A SS

shall install a stone crusher capable of destroying the boulders before their

removal. In an EPB, instead, the boulders shall stuck the screw conveyor obeying

divers to enter the excavation chambers in pressure and manually break the

boulders.

3. Keeping the pressure at the face is mandatory when using a SS. In any case. Also

in EPB all the excavation has to be executed in -closed-mode' i.e. by continuously

applying the pressure at the face. This guarantees of having lower settlement in

the surface.

4. In general EPB system is easier than SS. No specific separation plants are

required, no super-experienced personnel (for managing slurry density etc...) is



required and in fact. Today, in the world. EPB is largely the more applied

mechanized tunneling machine (the ratio shall be approx. 85% EPB and 15% SS

or even more).

5. A higher number of machines mean a high possibility to find on the market

second hand TBMs that shall be suitable for the application in this case; also

considering the short length of excavation of each stretch. This means cost

savings for the Project.

6. In urban areas, the installation of the slurry treatment plant shall be quite difficult

for the land occupancy.

7. In a SS monitoring the excavation parameters is more difficult. In fact, while with

an EPB the check of the weight of the extracted material for each stroke is easily

feasible and also easy to be comprehended: the monitoring of the quantity of

extracted material in a SS is performed by checking the slurry density with

complex formulations in a more complex way. So in case an extra-excavation is

not recognized immediately during construction_ the consequences shall be

catastrophic.

Fig 3.19 shows Cutter head in the TBM machine.

Fig 3.19: Cutter head in the TBM machine



The earth pressure boring machine has sensors in its cutter head it senses the pressure and

sends to the control room and the machine maintains the same pressure and works in it.

Minimum pressure maintained is 1.2 bars.

The cutter head consists of 45 cutters including gauge and twin cutters. The cutter cuts

the rock strata and removes the muck through the screw conveyor to the conveyor belt,

and then muck is collected in a muck bin of the locomotive which dumps out at the

surface. 16 jack cylinders with robotic erector guide the placing of the ring automatically.

The navigation surveyor direction keeps the TBM in the right motion.

3.3.6 WORKING OPERATION OF TBM

The muck which is removed from the cutter head by screw conveyer is transferred into

the muckbin. The muckbin has a capacity of 18 cum. The muckbin is carried out by a

locomotive which travels at a speed of around 2 KMPH. Stopping rods are provided at

the start of the TBM and the tunnel end so that when breaks fail they don’t hit the

machine directly. The muck bin is emptied by a gantry crane which takes around 15 min

to empty. The LOCO also carries segments. Sometimes Ice is also used in the tunnel

when the cutter head gets heated up to 50 °C. Fig 3.20 shows Working operation of TBM

(a) (b)



(c) (d)

(e) (f)

Fig 3.20: Working operation of TBM

Table 3.8 shows Feeder components supplied to the TBM (Grout mix).

Table 3.8: Feeder components supplied to the TBM (Grout mix)

Material Quantity for 1 cum

Liquid A

Cement OPC 53 320 kg

Bentonite 35 kg

Stabilizer 2 liters

Water 700 liters

Liquid B

Sodium silicate 80 liter (103 kg)



Fig 3.21 shows secondary grouting carried out inside the tunnel

Fig 3.21: Secondary Grouting Carried Out Inside the Tunnel

3.4 PRECAUTIONS FOR THE TUNNELLING WORK

In order to avoid hazards, it is necessary to lay down the safety precautions for the use of

machinery, electrical installations and labour in tunnels, during the construction period,

and arrange for their compliance.

The tunnels will be in the saprolite and fissured zone of the earth besides hard rock layer

at certain places. Fissured zone has the highest permeability, and blockage of this zone

(due to tunnelling) may result in substantial reduction in the effective transmission of

water. The BMRCL survey proposes that the tunnel will be drilled through the saprolite

and fissured zone of the earth. But experts opine that the blockage of fissured zone which

has highest permeability would affect transmission of water at later stages. Boring tunnel

using TBM would bring down the level of possible disturbance to the surrounding ground

and ensures the smooth tunnel wall. As a result, TBMs are widely used in high density

urban areas.

The front end of TBM consists of a rotating cutting wheel. Behind the cutting wheel is a

chamber where the excavated soil is either mixed with slurry or discharged as it is.

Tunnelling in Bangalore or in any other urban areas comes with a special challenge of

ensuring the minimal disturbance of ground surface. However, techniques like Earth



pressure balance and Bentonite slurry are preferred to the conventional open face method

due to the superior ground control. Experts opine that the tunnel boring machine would

do multiple tasks like drilling the tunnel, thrusting out the muck and sealing the inner

walls of the tunnel with pre-cast concrete elements. The mud will be slightly slushy since

the tunnel boring machine uses water while drilling. Adequate care has been taken while

BMRCL dug the tunnels. Sensors were placed to check the vulnerability and to check the

quantum of vibrations.

3.5 CHICKPET METRO STATION

Bangalore Chickpet metro station is located in Sevashrama sub-locality, Bangalore

locality, Bengaluru Urban District, Karnataka.

Table 3.9: Chickpet tunnel ring progress report

Month Rings/Month Cum.rings Balance

DEC -15 03 03 494

JAN-16 50 53 444

FEB-16 129 183 315

MAR-16 96 279 219

APR-16 58 337 161

MAY-16 45 382 116

JUN-16 23 405 93

JUL-16 35 439 58

AUG-16 21 460 37

SEP-16 37 497 0

Boring/mining work through Bangalore terrain from Chickpet station to Majestic station,

a distance of 747m. Took 10 months to tunnel 747m from Chickpet to Majestic. Tunnel

boring machine (TBM) Krishna set the stage for the much awaited phase of Namma

Metro as it made a dramatic breakthrough near Majestic on September 23rd

Friday. After

burrowing through hard rock and loose soil beneath the most densely populated areas of

Bengaluru, Krishna emerged on Friday at the Majestic south shaft in Chikkalalbagh area



near Kempegowda metro station. Fig 3.22 shows Krishna TBM breakthrough at Majestic

station and Table 3.9 shows Chickpet tunnel ring progress report.

Total length for from Chickpet to Majestic station =747m

Total no. of rings required=497 rings

Fig 3.22 Krishna TBM breakthrough at Majestic station



CHAPTER 4

PERSONAL EXPERIENCE

4.1 CHALLENGES FACED AT THE SITE

Construction projects are complex and time consuming undertakings that require the

interaction and cooperation of many different persons to accomplish. The construction

industry is typically divided into specialty areas, with each area requiring different skills,

resources and knowledge to participate effectively in it. In order to integrate and work

closely in each section it is a challenging task to one person especially when he/she is

fresh or beginner. In general, the following are the problems or challenges that will be

faced at the site.

Communication problem with workers at the site.

Shortage of working drawings like structural, architectural, sanitary, electrical and

some other details.

Weather condition of the site.

Shortage of knowledge in some portion of the work at the site.

Underestimation by workers such as engineers, foreman.

Unsatisfactory answers for questions from engineers.

Safety facility.

4.1.1 Weather Condition at the Site

Weather condition is one of the main problems that will be faced especially during the rainy

season. One should gain knowledge at site to adapt to such weather conditions and schedule

work accordingly such that the progress of the work will not be delayed. Shortage of

knowledge in some portion of works like quantity, bill of quantity, bar schedule and report

writing are also some of the challenges that will be faced. To solve these problems one

should ask his superior engineer at the site and read related literature to know more about this

works. The main challenges also include the sun light and dustiness of the site due to



construction equipment. Also since in rainy season, lot of challenges will be faced during

concreting work.

4.2 OVERALL BENEFITS OF THE INTERNSHIP

Internship is a class healed at the site to provide an enhanced understanding of the outside

working environment before the student graduate. The main aim of this internship is that to

teach students communication with different workers or employees, to improve practical skill

what they learned at class, up grading the theoretical knowledge in addition to the class,

improve their leadership skill, team playing skill etc.,

4.2.1 Improving Practical Skill

The aim of the internship is to address more practical knowledge for student. So, it is

necessary to obtain practical knowledge at the site as much possible within the four month.

The knowledge that will be earned in the class is helpful to get those practical works in the

site and totally different from the actual knowledge gained from the class. Thus it is

necessary to find some knowledge in the site which helps to work with the site environment

or site peoples.

Some of the practical knowledge that will be gained from the internship is as follows.

Construction of formwork and false work for some reinforced concrete structure. In any

construction work the first stage before casting of concrete is designing and constructing

of formwork. As it is explained in the work procedure the formwork and false work must

be stiff and must resist the fresh concrete till the concrete gain its strength. Thus the

construction stage of form work will be new for a fresher, it is necessary to gain practical

knowledge about how it is worked and erected.

Bar bending, positioning, splicing and tying, according the specified drawing. After the

formwork and false work is ready the bar bending, positioning and tying work goes next.

This work is done based on the working drawing provided in the working drawings

(structural drawing) by the design team of that specified structure. In most case it will be

new for a fresher to see such work since it is a practical work only performed at the site.



Casting and pouring of reinforced concrete structure and equipment used for casting.

Concrete is a vital material in any construction of reinforced concrete and is the main

constituent or ingredient of any reinforced concrete structure. Thus it is mandatory to

know this material in practice including how it is treated, placed (poured), mixed and the

equipment used for those work. One should get the practical knowledge in terms of those

listed aspects of concrete.

Different construction equipment’s are used in the construction site. Many of great

structures before are a product of numerous human power and countless days inspired by

great powers. Machines are capable of handling tough work which may be beyond the

scope of human labour to be performed. They can be expected to work with fair degree of

effectiveness even under adverse weather, climate or topographical conditions. One

should generally know how equipment’s are used in the site including their specific

purpose. The operation of equipment’s varies from one another. Thus it is necessary to

generally know how equipment’s are used in the site.

4.2.2 Upgrading the Theoretical Knowledge

The internship class is not only depending on the practical aspect but it also help students

to upgrade or increase knowledge on already that they have. It is necessary to integrate

the practical knowledge with that of the theory learnt in the class in different places in

order to get more knowledge. The internship class will be very interesting in terms of

upgrading theoretical knowledge and one should learn from the site some theories that

haven’t learned in the class room by searching different related literature. Some of these

are as follows.

Quantity surveying

Structural design of shear wall and its advantage

Construction equipment

One should learn those things in exclusive causes it is hard to read and understand

everything from books and asking some peoples at site to those things will be difficult.



Generally he/she will change them self a little bit after the internship period compared to

knowledge before it.

4.2.3 Upgrading Interpersonal Communication Skill

Communication is sharing or exchanging information or ideas with others in order to get

some messages and knowledge. The communication systems within the building design

and construction enterprise has taken on a large role in the achievement of profitability

and efficiency. Construction is one of the places that ask a good communication skill

either managing every trade of work or asking what is growing over there. So,

communication is an important way of learning, which can be defined formally as the act,

process or experience of gaining knowledge or skills and sharing what we know. But one

should improve and know how to communicate with different classes of workers in the

site.

4.2.4 Improving Team Playing Skill

Team playing skill for construction work team works, especially for engineers, involve in

every piece of task and achieving good team playing skill is essential for effective

completion of tasks and increasing productivity. In the construction site the work is

already a team work and it needs more closeness of workers to solve problems arise in

different aspects, misunderstanding in the drawing or working methodology and consult

every work. More or less one should improve his team work status by working together

with different professionals, student and workers as a whole in the civil engineering

works and consulting.

4.2.5 Improving Leadership Skill

Leadership is the process of influencing individuals or groups to accomplish an

organization goal or mission. One should see how each worker is controlled and

organized to perform its day to day activities. Among all other management seen human

resource management is the most important one. One should actually observe the method

of controlling the working time and amount of work done by each worker so that the

work proceeds according to the work plan (schedule). For effective leadership one should



understand that personal values like confidence, effective communication and devotion

are very important.

In order to be good Leadership the following criteria should be fulfilled.

Be technically proficient

Seek responsibility and take responsibility for your actions.

Make sound and timely decisions.

Know your people and look out for their well-being.

Keep your workers informed.

Develop a sense of responsibility in your workers.

Ensure that tasks are understood, supervised and accomplished.

Able to communicate clearly and efficient.



REFERENCES

[1] M S Shetty, 2012, “Construction Technology Theory and Practice”, 6th

edition,

published by S Chand and Company Ltd.

[2] IS: 456, Plain and reinforced concrete-code of practice, Bureau of Indian Standards,

New Delhi, 2000.

[3] IS: 383, Indian standards specification for coarse and fine aggregates from natural

sources for concrete, Bureau of Indian Standards, New Delhi, 1970.

[4] IS: 10262, recommended guidelines for concrete mix design, Bureau of Indian

Standards, New Delhi, 1999.

[5] Raghavendra V, Stanley Jose, G.H Arjun Shounak, Dr. T.G Sitharam “Finite

Element Analysis Of Underground Metro Tunnels” International Journal of Civil

Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 –

6316(Online), Volume 6, Issue 2, February (2015), pp. 06-15.

[6] www.coastalprojects.co

http://www.coastalprojects.co/

4 Month Internship Report on Tunnel construction at Chickpet Metro Station

Engineering

Transcript of 4 Month Internship Report on Tunnel construction at Chickpet Metro Station