2. REPORT OF INPLANT TRAINING
LARSEN AND TOUBRO PVT. LTD.
THE PROJECT MANAGER
LARSEN AND TOUBRO PVT.LTD
PDS HEMANTH KUMAR
VISVESVARAYA NATIONAL INSTITUTE OF
TECHNOLOGY - NAGPUR
1 The CHENNAI METRO
2 EHS Department
3 ROLE OF L&T
5 BATCHING PLANT
6 QUALITY CONTROL
7 CONSTRUCTION OF STATIONS
8 DIAPHRAGAM WALL
10 BROAD OUTLOOK OF STATION
11 MECHANICAL ELECTRICAL AND
12 CONSTRUCTION EQUIPMENT
AND VEHICLE USED
Chennai Metropolis has been growing rapidly and the traffic volumes on the roads have also
been increasing enormously. Hence the need for a new rail based rapid transport system has
been felt and towards this objective the Government of Tamil Nadu have decided to
implement the Chennai Metro Rail Project. This project aims at providing the people of
Chennai with a fast, reliable, convenient, efficient, modern and economical mode of public
transport, which is properly integrated with other forms of public and private transport
including buses, sub-urban trains and MRTS
A Detailed Project Report (DPR) relating to the Chennai Metro Rail Project was prepared and
submitted by the Delhi Metro Rail Corporation Limited (DMRC) who have successfully
designed and implemented the Delhi Metro Rail Project. The DPR envisages the creation of 2
initial corridors under the proposed phase-1 of the Chennai Metro Rail Project as shown
Washermenpet to Airport 23.1 kms
Chennai Central to St.Thomas Mount 22.0 kms
Total 45.1 kms.
The details of the two corridors are given below:
Washermenpet–Broadway (Prakasam Road)–Chennai Central Station–Rippon Building–
along Cooum River–Government Estate–Tarapore Towers–Spencers–Gemini–Anna Salai–
Chennai Central–along EVR Periyar Salai–Vepery–Kilpauk Medical College–Aminjikarai–
Shenoy Nagar–Annanagar East-Anna Nagar 2nd avenue–Tirumangalam–Koyambedu-
CMBT–along Inner Ring Road–Vadapalani–Ashok Nagar–SIDCO–Alandur–St. Thomas
The portions of Corridor-1 with a length of 14.3 kms. from Washermanpet to Saidapet, and
Corridor-2 with a length of 9.7 kms. from Chennai Central to Anna Nagar 2nd Avenue will
be underground and the remainder elevated. The alignment and stations given above are
tentative and subject to change during detailed design and execution.
5. ENVIORNMENT HEALTH SAFETY (EHS) DEPARTMENT
The EHS department of Larsen and Toubro is based on EHS Management System and
Procedures that follows the codes ISO14001 and OHSAS 18001.
OHSAS stands for Occupational Health Safety Assessment Series. Occupational safety
means the safety norms to be followed on a construction site or any other workplace for that
matter. The EHS Procedures can be divided into 3 parts:
1. System Procedures (S.P): It defines all the legislative requirements that are to be
followed on site and also defines the roles and responsibilities of the staff and workmen
working in the direction of safety.
2. Control Procedures (C.P): It defines all the measures required to control the no. of
accidents on site thus ensures a safer environment at the working site. It also defines the
use of PPE (Personal Protective Equipment) like Safety Helmet, Gloves, Safety Jacket,
Safety Shoes etc. while on site.
3. General Procedures (G.P): It defines all the methods of workmen welfare and safety
EHS department organises a training for the workmen so that each of them can safely work at
High visibility safety vests at first glance appear to be the same now as they have been for
many years. But there have been many improvements and variations made to make reflective
safety vests more effective and comfortable for workers. Depending on the estimated
potential hazards of your job, the type of vest you wear may or may not be American
National Standards Institute (ANSI) and Occupational Safety & Health Administration
Non-ANSI approved traffic safety vests are used in what is termed Class 1 environments,
which are low traffic areas, like those faced by parking lot attendants. The most often used
Orange safety vest
Yellow safety vest
Lime green safety vest
6. A sign board
indicating the use of PERSONAL PROTECTIV EQUIPMENTS at site for safety.
The construction site is filled with many such sign boards indicating the safety measures that
are to be taken while working at the site.
EHS department also issues a safe to startcard on dialy basis after observing that safety
measures are taken at the site where work has to be done
7. As the site consists of various engineers, sub-contractors, electricians, supervisors and
workmen, L&T follows a unique system of colour coding that helps in identification of
people working on the site.
The colour codes is the colour of helmet wore by the person. The colour codes are as follows:
Green Helmet: For Safety Supervisor
Red Helmet: For Electrician
Purple Helmet: For Supervisors
White Helmet: For Engineers
Yellow Helmet: For Workmen
Also the EHS department maintains a log sheet which indicates the location, activity, s/c, and
no. of workmen working at that location. This helps to ensure that no workmen is anyway in
danger of any fatality or danger.
The “GOLDEN SAFETY RULE” says that for a work which is above the height of 1.8m
should be done with the help of a life line is the site do not comprise anchorage.
EHS department also ensures that the no. of Near Miss cases are maintained low as “A Near
Miss could be Next Accident”. And the lower the no. of near miss cases lower is the chance
of any fatality on site. It also organises a PDCA (Plan Do Check Act) cycle wherein the
officers go for a safety drive.
When any new employee or workmen or trainee join the site, he undergoes a “safety
induction process” in which he is taught the various safety measures to be maintained at the
site. The induction process of a trainee is done by the safety officer or safety in-charge of the
Before allowing a workmen to join the site he also undergoes a medical check-up and then a
screening test by the incharge of the department he is to work in. On passing the screening
test he undergoes the induction process and then he is ready to work
8. ROLE OF L&T IN CHENNAI METRO
Larsen & Toubro (L&T) and Afcons Infrastructure were the only two companies who bid for
completing the Government Estate to Saidapet section (contracts UAA-02 and UAA-03) of
the International Airport to Washermenpet metro line. This section was originally awarded to
Gammon & Mosmetrostroy, but they abruptly pulled out of the project earlier this year due to
rising costs and left behind material & equipment worth at least Rs 200 crore
After canceling Gammon & Mosmetrostroy’s contract and encashing their Rs 100 crore bank
guarantee , the CMRL invited bids for completing the 2 sections:
• BW-UG-02 (originally UAA-02) – Design and construction of balance works of
underground stations at Government Estate, LIC Building and Thousand Lights and
• BW-UG-03 (originally UAA-03) – Design and construction of balance works of
underground stations at AG-DMS, Teynampet, Nanadanam, Saidapet and Saidapet ramp
portion and associated tunnels
Here’s a map which shows these 2 sections which happen to be continuous
9. The project budget for BW UG 02 IS 473.6 Crores and the duration is 787 days
For the metro project the fund contribution is 21% by central government
20% by state government
Remaining 59% by JICA (JAPAN INTERNATIONAL COOPERATION AGENCY)
SURVEYS AND INVESTIGATIONS DONE BEFORECONSTRUCTION
Preliminary building survey
Building assessment plan
• Land surveying : To determine the boundaries and areas of parcels of land, also
known as property survey, boundary survey or cadastral survey.
• Topographic survey : To prepare a plan/ map of a region which includes natural
as well as and man-made features including elevation.
• Engineering survey : To collect requisite data for planning, design and execution
of engineering projects. Three broad steps are
1) Reconnaissance survey : To explore site conditions and availability of
2) Preliminary survey : To collect adequate data to prepare plan / map of area to
be used for planning and design.
10. 3) Location survey : To set out work on the ground for actual
construction / execution of the project.
The first stage of soil investigation for the metro work had begun in different places
near the Madras High Court for collecting soil data for construction of metro stations
and underground tracks. As part of the soil investigation work bore-holing was being
executed to collect soil data.
Each bore-holing needs two to three days and as a whole 30 to 45 days for getting
soil data for a particular stretch,. Once the collection of soil data is over the second
stage would be the shifting of underground utilities after which tender would be
awarded for track and station works.
Subsoil conditions are examined using test borings, provided by soil engineer
Number of borings and location of borings depends on building type and site
Typically for uniform soil conditions borings are spaced 100-150′ apart, for more
detailed work, where soil footings are closely spaced and soil conditions are not
even borings are spaced 50′ apart.
Larger open warehouse type spaces, where fewer columns are present (long span)
required less boring samples.
Borings must extend to firm Strata (go through unsuitable foundation soil) and then
extend at least 20 feet more into bearable soil.
Location of borings samples are indicated on engineer plan.
Borings are not taken directly under proposed columns.
Borings indicate: depth, soil classification (according to the unified soil system), and
moisture content and sometimes ground water level is shown as well. (Physical
properties: particle size, moisture content, density).
Soil report recommendation should be based on testing of materials obtained from
on site borings and to include:
Bearing capacity of soil.
Foundation design recommendations.
Paving design recommendations.
11. Compaction of soil.
Lateral strength (active, passive, and coefficient of friction).
High Water Table.
Presence of trouble soils: Peat, soft clay, loose silt, or fine water bearing sands.
Rock close to the surface (require blasting for excavations).
Dumps or Fills.
Evidence of slides or subsidence.
The soil of Chennai mostly consists of clay, sedimentary rocks and sandstone. Part
of city like T. Nagar, West Mambalam, Anna Nagar, Villivakkam, Perambur and
Virugambakkam have clay soil. The water level is now at an average of 4.70
metre,therefore there was a need of dewatering borewells while construction.
Building Assesment Plan:
General information was collected regarding the building itself, such as the age, construction
features, use, furnishings, renovations, local pollutant sources and general maintenance.
Environmental measurements including comfort parameters such as light, sound, temperature
and relative humidity as well as pollutant concentrations such as particulate matter, volatile
organic compounds (VOCs), biological contaminants and radon were collected at three or
more sites within the indoor study space and at one outdoor site for each building.
Based on observations of engineering; properties during geotechnical construction are an
integral part of the design of underground structures. This research presents instrumentation
as a tool to assist with these measurement observations, determine the need for modifications
to loading or support arrangement. Also apart from above construction control,
instrumentation is also indispensable for site investigation, design verification and safety of
the structure. Instrumentation used in the construction of tunnels and subways can be
implemented in three stagesbefore, during operation and during operation are examined.
Metro Railway Tunnels are constructed in populated area and have a more comprehensive
instrumentation and monitoring program that additionally includes monitoring of ground
conditions, underground water levels, tilt and settlement of nearby buildings or other
structures of interest in the vicinity of the tunnel alignment. Instrumentation monitoring for
metro railway tunnels includes monitoring of the structures under construction together with
the ground, buildings and other facilities within the predicted zone of influence. Furthermore,
instrumentation and subway tunnels in and around them increase accuracy of the different
12. layers of the earth and excavation of the surrounding structures and make safety and
accuracy. This paper presents the features of sophisticated instrumentation available today for
geotechnical monitoring. A wide range of sophistic have been described with their
applications ted electronic and mechanical instrumentation with different instrumentation
schemes used to meet the requirements of different types of structures.
The settlement marker is used to measure a localised settlement or heave of roads, slopes,
embankments, utility pipes and cables.
Building settlement markers:
Ground settlement markers
Pavement settlement markers
Vibration monitoring sensors
A concrete plant, also known as a batch plant or batching plant or a concrete batching plant,
is equipment that combines various ingredients to form concrete. Some of these inputs
include water, air, admixtures, sand, aggregate (rocks, gravel, etc.), fly ash, silica fume, slag,
Different grades of concrete used were prepared in batching plant as per
requirement such as M45 for piling and D-wall, M35 for slab and M20 for PCC.
Capacity of batching plant is 1 m3 per batch
Ingredients used were OPC 53 cement, fly ash, 20mm & 12mm coarse aggregate ,
reversed and manufactured sand ,water and admixtures.
Super plasticizer used was polycarboxylate ether ( Fosroc auromix 400) used for
increasing initial settling time (0.7% used)
20 % of flyash was used for concrete preparation.
A Batching Plant has following parts
HOPPER: It is the place where all the materials required for the mix design is
dumped and it contains a net of iron bars that filters the big pieces and stops them
from entering in the plant.
BELT CONVEYOR: It carries the material required from the hopper to the
COMPARTMENT BIN:A compartment where all the material i.e. the coarse agg,,
fine agg. Are segregated and there are different compartments for each material so
that no mixing happens before the starting of plant.
13. MAIN STRUCTURE: It is the part where all the mixing happens. It comprises of
i) Aggregate gate: These are air pressure controlled gates that open at the time of
mixing and aggregate from bin is sent to the bucket for further process.
ii) Skip wire Bucket: This carries the aggregates from the gates to the pan mixer. It
rests on load cells that calculate the amount of aggregate in it and thus carries only
the required amount.
iii) Pan Mixer: It the part which does the mixing of the various components required
for the mix design. The aggregates from the gates are filled in the sip bucket and
are carried to this pan mixer. The cement, Fly Ash from the silos are sent to the
cement weigher and are sent to mixer. Similarly water from water weigher is sent
to the pan mixer. Here mixing is done for 30seconds and then the concrete of the
required mix design is ready.
iv) Control Unit: The whole process of mixing is controlled from a computer called
the control unit of the plant. The weight and mix design of the concrete is decided
and fed in a computer which runs the plant automatically to give us the required
2) SILOS: These are storage unit that stores cement and fly ash and supplies them to the
batching plant when required. The Silos at plant have a capacity of 100ton for cement
storage and 40 ton for flyash storage . They also consists of a SAFETY VALVE to stop
the silo from bursting while its filling and when it gets emptied.
3) CHILLING PLANT are used for concrete mixing and cooling applications with
4oC and 1oC chilled water temperatures, as per the process requirement to
obtain required temperature on site (28-320C).Capacity of tank is 50,000 L.
4) CONCRETE PUMP: A mechanical device which is used to pump concrete from one
place to another.These pumps can pump concrete to a height of 60m. It consist of 2
cylinders viz. Pumping and Differential Cylinders that acts alternately to pump concrete.
This department is responsible for ensuring the quality of work on site, also it conducts
various tests on material used for construction and ensures that no faulty material is being
This department is also called QA/QC (QUALITY ASSESSMENT/QUALITY
QC- is responsible for controlling the assured quality and is a site level work.
QA- is responsible for assurance of quality to client and is all done at the tender level.
The department follows ISO9001, 2005 for defining the quality of the material used in the
The PQP contains Quality Management System, Management Responsibility, Resource
Management, Product Realization and Measurement Analysis and Improvements
Tests on cement
14. NORMAL CONSISTENCY: The consistency is measured by the Vicat apparatus using a
10mm diameter plunger. Acceptable limit is 5-7 mmfrom bottom.
COMPRESSIVE SRENGTH : Cubes of 50 mm2 area are prepared and tested after 3,7 &
28 days after curing and they must satisfy limits as per IS standards.
INITAIL SETTING TIME AND FINAL SETTING TIME: Initial setting time should not
be less than 30 minutes for OPC and final setting time should be around 10 hours.
FINENESS TEST: The percentage of residue retained on 90 micron sieve should not
SOUNDNESS TEST: Soundness value of cement according to Le-Chatlier test should not
These are used for the following reasons:
1. Reduces the Heat of Hydration of cement.
2. Reduces the Shrinkage effect of cement.
3. Its economical.
These are of 2 types:
1. Fine aggregate(less than 4.75mm particle size)
2. Coarse aggregate(more than 4.75mm )
TESTS ON AGGREGATE
FLAKINESS AND ELONGATION INDEX
SPECIFIC GRAVITY TEST(PYCNOMETER)
BULKING OF SAND
TESTS FOR ADMIXTURES
To test the quality of admixture various test are carried out.
The following are the desired results of the tests on the aggregates:
1. Dry Material Content: +/- 3% of the value stated by the manufacture.
2. Relative density:+/- 0.2 of the value stated by the
3. pH: Should not be less than 6.
4. Ash content: +/- 1 of the value stated by the manufacturer.
15. TESTS ON CONCRETE
COMPRESSIVE SRENGTH : Cubes of 150x150 mm2 area are prepared and tested after
3,7 & 28 days after curing and they must satisfy limits as per IS standards.
SLUMP TEST: Slump of workable concrete should be around 80-120 mm , pumpable
concrete 150 mm and 170±25 mm for concrete used for D-wall and piles.
TEMPERATURE should be around 28 to 320C on site.
CONSTRUCTION OF THE STATIONS & TUNNELS
CUT AND COVER METHOD
Bottom up method: Buildings with underground basements are built by bottom-up
method where sub-structure and super-structure floors are constructed sequentially
from the bottom of the sub-structure or lowest level of basement to the top of the
super-structure and is called as bottom-up method which is simple in both design and
Top down method:Top-down construction method as the name implies, is a
construction method, which builds the permanent structure members of the basement
along with the excavation from the top to the bottom. Top-down method is mainly
used for two types of urban structures, tall buildings with deep basements and
underground structures such as car parks, underpasses and subway stations
Out of 3 stations, LIC and Thousand Lights stations are constructed by top down
method and government estate station is constructed by bottom up method
The typical construction procedure of top down construction is as follows
Construct the retaining wall.
Construct piles. Place the steel columns or stanchions where the piles are
Proceed to the first stage of excavation.
Cast the floor slab of first basement level
16. Begin to construct the superstructure
Proceed to the second stage of excavation; cast the floor slab of the second
Repeat the same procedure till the desired depth is reached
Construct the foundation slab and ground beams, etc. Complete the basement
Keep constructing the superstructure till it gets finished.
INSTALLATION OF RETAINING WALL
The underground retaining wall which is usually a diaphragm wall, is installed before
EXCAVATION AND INSTALLATION OF STEEL STRUT
17. The soil is excavated just below roof slab level of the underground structure. Struts are
installed to support the retaining walls, which in turn support the soil at the sides
Construction of underground structure
The roof slab is constructed, with access openings provided on the slab for works to proceed
downwards. The roof slabs not only provides a massive support across the .
Construction of underground structure
The next level of slab is constructed, and this process progresses downwards till the base
slab is completed
Construction of underground structure
18. The side walls are constructed upwards, followed by removal of the intermediate struts. The
access openings on the roof slab are then sealed.
Backfilling and reinstatement
After the underground structure is completed, the soil is backfilled to the top strut level
before the strut is removed. This is followed by completely backfilling the top of the
underground structure and finally reinstating the surface areas.
19. DIAPHRAGAM WALL
A diaphragm wall is a structural concrete wall constructed in a deep trench
excavation, either cast in situ or using precast concrete components.
Diaphragms walls are often used on congested sites, close to existing structures,
where there is restricted headroom, or where the excavation is of a depth that
would otherwise require the removal of much greater volumes of soil to provide
stable battered slopes.
The walls generally range in thickness from 500-1,500 mm and can be excavated
to depths of over 50 m. Excavation is typically carried out using rope-suspended
mechanical or hydraulically-operated grabs. Specific ground conditions or greater
depths may require the use of hydromills – hydraulically-operated reverse
circulation trench cutters – to penetrate into hard rock by ‘cutting’ rather than
‘digging’. Hydromills can achieve depths of up to 80 m.
The excavation stability is maintained by the use of a drilling fluid, usually a
bentonite slurry. This is a controlled mixture that has thixotropic properties,
meaning that it exerts a pressure in excess of the earth and hydrostatic pressures
on the sides of the excavation. The walls are constructed, using reinforced or
unreinforced concrete, in discrete panel lengths generally ranging between 2.5-7
m. Purpose-made stop ends can be used to form the joints between adjacent
panels, with a water bar incorporated across the joints. More complicated
arrangements such as ‘L’ or ‘T’-shaped panels can be constructed where
additional bending moment capacity or wall stiffness is required.
The units are installed in a trench filled with a special mixture of bentonite and
cement with a retarder added to control the setting time. Ground anchors are used
to tie the panels or posts to the retained earth to provide stability.
M45 grade of concrete is used with Fe 500 steel reinforcement
Thickness of d wall is 800mm at entrances and 1 metre thick at station
Depth of D wall varies from 22 to 26 m accordind to the hard strata depth
Polymer used for stability of soil is bentonite
couplers placed in the reinforcement panel to connect the steel bars of slab with D
Minimum width of panel of steel cage is 2.5
Guide wall is constructed before excavation for Dwall for soil stability. It is
constructed using M20 grade of concrete and it is about 1.5 m deep and 1.2 m thick
Grouting is done to stop seepage due to defects in the wall
Cuffer wall is constructed parallel to Dwall which is used for finishing and additional
protection against seepage
KODEN test is done to check verticality of d walls.
20. Sequence of constructionof D wall:
Guide wall construction
Trenching upto feet level of required depth
Pouring bentonite mixto provide stability
Cage lowering and placing the couplers properly
Concreting the d wall
Grouting of d wall
Plunge columns:A plunge column is a structural steel or concrete section embedded in a
freshly poured concrete pile, eliminating the need for baseplates and holding-down bolts.
Construction procedure is same as that of D-wall
Plunge column rests on pile of 1.2 meter diameter
I steel section reinforcement in used while construction which is then filled with
M45 grade concrete is used
Plunge column acts as a support to horizontal slab of long span resting on D wall.
STUB COLUMN: These are additional column provided temporarily to support auxillary
loading and support during construction.
SLAB : It is a horizontal structure used to transfer vertical loading to coloumn
RCC Slabs Construction at three different levels i.e. at roof level, concourse level and base
level present at different depth and serving different purpses.
M35 Grade of concrete and HYSD Fe500 is used for construction
Slab is two way reinforced by steel rods which are attached to d wall by couplers and
Pullout test is performed initially to ensure fixidity of bars
Thickness of slab is around 800 mm with minimum cover of twice the maximum size
of coarse aggregate used.
Additional lateral reinforcement is provided to avoid shear failure.
Additional water proofing sheet are laid while concreting to avoid seepage
Temporary PCC layer of M20 Concrete was laid below steel reinforcement before
Concrete was properly compacted using needle vibrator and maximum height upto
which pouring pipe can be raised is 1.5 meter to avoid segregation.
Total length of metro in phase 1 is 46 km out of which 23 km is underground
Internal diameter of tunnel is 5.8 meter
Tunnel is made of many rings of width 1.4 meter.
Each ring consist of six segments 275 mm thick made of M50 grade concrete.
One ring consist of 5 majour segments and a key that is used for locking.
Tunnel of initial diameter 6.6 meter is dug by TBM machine
Grouting of 120 mm is done by cement concrete and sodium silicate to
accelerate the hardening process to avoid seepage.
TBM applies a force of 25,000 to 40,000 knm
Soil excavated is carried using belt conveyer or trolleys.
Average speed of excavation is 5 cm per minute.
Temporary tracks and ventilation pipes are provided .
Distance between two tunnels is 7.7 m.
There will be cross passages after every 250 m in case of any emergency.
BROAD OUTLOOK OF METRO STATION
Metro station has four entrances and exits.
Station has three levels- 1)Roof level 2)Concourse level 3)Platform
Roof level is 3 to 4 meters below ground level.
Concourse level is 6 meters below roof level
Level difference between concourse and platform level is 8 m.
Platform is at height of 2 m from base level
Concourse level consist of ticket vending machines ,retail shops
,signal equipments and control room ,communication equipments
,anciliary substation room ,AC and ventilation monitoring room
,cleaner room ,refuse and toilets ,first aid room.
Platform level consist of rail track , signalling equipments ,power
Vent Shafts are provided at the ends of station to maintain pressure
Station length is 220 to 250 m and width is about 22 m.
The station box is dog bone structure
It is the heart of metro station which provides power ,water and
cool air to station.
It consist of DG compound, transformer room, chiller plant
,storage tank .
22. Before constructing the anciliary building shoring of the
periphery of the site is done to avoid the failure of surroundind
Soft pile of 300 mm dia are constructed at the periphery of the
Soldiers piles are provided as additional support to soft piles
Struts are fixed to provide lateral support
After the entire process of excavation and construction soldier
piles can be removed if possible for future use
Anciliary building is G+2 structure
Mechanical electrical and plumbing (MEP)
These departments govern the following operations:
Air ventilation at stations
Car alarm system
Signalling and telecommunication system
Lift and escalators
Construction equipments and vehicles used