ACKNOWLEDGEMENTSThe internship at LARSEN & TOUBRO at their prestigious DMRC CC-28 project, helped in my learning stage, towards the threshold of working in Industries. I have got an intense knowledge on the design, construction, consultancy and safety activities which are carrying out in the construction site.

First of all I would like to thank my mentor Mr. S.Sundar Rajan (Project Manager) whose keen interest, sheer motivation and proper guidance helped me in completing my internship.

I also thank the following people for showing keen interest towards completion of my internship Mr. Yasir Khan(planning), Mr.Viraj Gupta(Designing), Mr.Praveen Roy(Safety in charge), Mr. Sandeep De (Stretch ‘B’), Mr.R.K.Sharma (P.C. Yard) and Mr.Vikas (Erection)for guiding me throughout the internship.

TABLE OF CONTENTS1. Preface

2. Introduction

▪ L & T

▪ Project CC-28

◦ Brief Contract Details

◦ Network

◦ Need for a metro

3. Safety, Health and Environmental Plan (SHE)

4. Planning

▪ Daily Progress Report (DPR)

▪ Work program

▪ General Alignment Drawing (GAD)

▪ Project Quality Plan (PQP)

▪ Contract Agreement

5. Design

▪ Reference IS Codes

▪ Design Basis Report (DBR)

▪ Detailed Drawings

6. STRECH-‘B’

▪ Piling

▪ Pile Cap

▪ Pier

▪ Pier Cap

7. Casting Yard

▪ Casting Segment

▪ Tests on cement consistency

▪ Batching Plant

8. Erection

▪ Introduction

▪ Steps involved for erection

▪ Risk involved & Precautions

9. Conclusion

10. References

PREFACE

This report discusses various activities that were undertaken in various departments as a part of the training at Larsen & Toubro. The report has been presented in different parts as follows:

The first part of the report provides an insight into the Larsen & Toubro Limited giving us an introduction about the Project CC-28.

The second part of the report deals with the on-site activities, Project CC-28 to be precise. It is further split up into sub-sections which provide insight into the construction of piles, pile cap, piers, pier cap, casting of segment and erection. Also providing the necessary precaution and care to be taken.

INTRODUCTION

Larsen & Toubro Limited:

Larsen & Toubro Limited is the biggest legacy of two Danish Engineers, who built a world class organization that is professionally managed an d a leader in India’s engineering and construction industry. It was the business of cement that brought the young Henning Holck -Larsen and S.K. Toubro into India. They arrived on Indian shore as representatives of the Danish engineering firm F L Smidth & Co in connection with the merger of cement companies that later grouped into the Associated Cement Companies. Together, Holck-Larsen and Toubro, founded the partnership firm of L&T in 1938, which was converted into a limited company on February 7, 1946. Today, this has metamorphosed into one of India’s biggest success stories. The company has grown from humble origins to a large conglomerate spanning engineering and construction. Larsen & Toubro Construction is India’s largest construction organization. Many of the country’s prized landmarks - its exquisite buildings, tallest structures, largest industrial projects, longest flyover, and highest viaducts - have been built by it .Leading-edge capabilities cover every discipline of construction: civil, mechanical, electrical and instrumentation. L&T Construction has the resources to execute projects of large magnitude and technological complexity in any part of the world. The business of L&T Construction is organized in six business sectors which will primarily be responsible for Technology Development, Business Development, International Tendering and work as Investment Centers. Headquarters in Chennai, India. In India, 7 Regional Offices and over 250 project sites. In overseas it has offices in Gulf and other overseas locations. L&T Construction’s cutting edge capabilities cover every discipline of construction – civil, mechanical, and electrical and instrumentation engineering and services extend to large industrial and infrastructure projects from concept to commissioning. L&T Construction has played a prominent role in India’s industrial and infrastructure development by executing several projects across length and breadth of the country and abroad. For ease of operations and better project management, in-depth technology and business development as

well as to focus attention on domestic and international project execution, entire operation of L&T Construction is structured into four Independent Companies.

PROJECT CC-28SCOPE:

PROJECT TILLTE:

PART DESIGN AND CONSTRUCTION OF ELEVATED VIADUCT, ELEVATED RAMP AND 5 ELEVATED STATIONS VIZ SHAKURPUR, PUNJABI BAGH, E.S.I HOSPITAL, RAJOURI GARDEN AND MAYAPURI STATIONS INCLUDING ARCHITECTURAL FINISHING WORKS FROM (CHAINAGE 5675.94.00 M TO 13600.00 M) OF LINE 7 MUKUNDPUR-YAMUNA VIHAR CORRIDOR OF PHASE-III DELHIMRTS.

PROJECT SITE LOCATION:

CUSTOMER: Delhi Metro Rail Corporation Limited

CONTRACTER/ORGANISATION: Infrastructure Independent Company Larsen & Toubro Limited

CONTRACT AGREEMENT Number AND DATE: DMRC/20/lll-058/2012 & 30.8.2012

CONTRACT DURATION: 30 MONTHS

SAFETY, HEALTH AND ENVIRONMENTAL PLAN(SHE)

 RULES & REGULATIONS:    

● No workmen below 18 years and above 58 years of age shall be engaged for a job.  ● Visitors can enter the site after EHS Induction with the visitor pass. He should be provided Safety helmet & safety Shoes.

● Smoking is strictly prohibited at workplace.  

● Nobody is allowed to enter the site without wearing safety helmet. Chinstrap of safety helmet shall be always on.

● No one is allowed to enter into workplace and work at site without adequate foot protection (including female worker).

● Usage of eye protection equipment shall be ensured.

● Rigid barrication must be provided around the excavated pits, and barrication shall be maintained till the backfilling is done. Safe approach is to be ensured into every excavation.

● Adequate illumination at workplace shall be ensured before starting the job at night.  

● All the dangerous moving parts of the portable/fixed machinery being used shall be adequately guarded.    

● Erection zone and dismantling zone shall be barricaded and nobody will be allowed to stand under the suspended loads.    

● Material shall not be thrown from the height. Proper arrangement of Debris Chute can be installed.  

● All major, minor accidents near misses and unhygienic conditions must be reported.  

● Debris, scrap and other material to be cleared then and there from the work place and at the time of closing of work every day.

● No children shall be allowed to enter the workplace.

● Safety signs and notices must be displayed and followed.  

● Consumption of alcohol and drugs is prohibited.

● Must be aware about the locations of the first aid canter, fire extinguisher, emergency assembly point and emergency siren.  

▪ SAFETY APPLIANCES

The requirement of sufficient number of safety appliances are planned well in advance and made available at stores.  

▪HEAD PROTECTION

Every individual entering the site must wear safety helmet, confirming to IS: 2925-1984 with the chinstrap fixed to the chin.  

▪FOOT AND LEG PROTECTION  

Safety footwear with steel toe is essential on site to prevent crush injuries to our toes and injury due to striking against the object.

▪HEARING PROTECTION

Excessive noise causes damage to the inner ear and permanent loss of hearing. To protect ears use ear plugs/ear muff as suitable.

DAILY PROGRESS REPORT

PLANNINGPlanning is a fundamental and challenging activity in the management and execution of construction projects. It involves the choice of technology, the definition of work tasks, the estimation of the required resources and duration for individual tasks, and the identification of any interactions among the different work tasks. A good construction plan is the basis for developing the budget and the schedule for work. Mainly the Planning Department works under the following sub-heads:

▪ Cost Estimation

▪ Mobilization

▪ Contract Management

▪ Subcontractor Billing

▪ Client Billing

▪ Documentatio

Daily Progress Report The Daily Progress Report Dated: 22-12-2013 is shown in the image below.As it can be easily described from the image that DPR gives us the preliminary idea of the Weather of the day , Equipment deployed on the same day , Staff and Labor working on that day , Planned and achieved work up to that day and Hindrances occurred during the work that day. It also shows if that hindrance has been removed or sorted out or not.

WorkProgram Work program is a document of the progress of the project datewise. It is not prepared on the daily or weekly basis. It is prepared before the commencement of project. The Start date and the Finish date of every minor to major work of the project is mentioned in this. The work has to be carried out as per the dates so that it can be easily finished before the dead-line. The required number of days for a particular type of work for e.g. survey of the site, reconnisance etc. are mentioned In this.

General Alignment Drawing As it is clearly specified from the name itself, it is the alignment drawing of the project part wise. Actually it gives the idea about Vertical Alignment in elevation, Horizontal Alignment in elevation. The geometrical layout in plan of a particular part of the site which constitutes different pier numbers along with a specific mention of the left and right span of every pier is mentioned in alignment drawing. The image which is shown in general alignment drawing is the detailed GPS image of that part. Also known as Alignment Plan and Span Arrangement Drawing.

Some basic information about chainage which is given in GAD is as follows:

◦ Rail level

◦ Pier cap top level

◦ Lowest ground level in pile cap zone

◦ Pile cap top level

◦ Minimum pile length

◦ Pier type

◦ Reference drawing number

◦ Relevant bore hole

Project Quality Plan ◦Definition:

An apex level document at project site specifying which procedure and associated resources shall be applied by whom and when to a specific project, product, process or contract.

◦Purpose:

Management summary of quality related activities required to meet terms of contract.

It is mainly divided into following parts:

◦ General :- scope, purpose, terms and definitions.

◦ Quality Management System: - it includes general requirement and documentation requirement of contract.

◦ Management Responsibility: - It includes quality objective, quality policy, quality planning, responsibility, authority and communication.

◦ Resource Management

◦ Product Realization

◦ Measurement, Analysis and Improvement: - it includes customer satisfaction, internal audit, and measurement of processes, improvement, corrective and preventive measures.

CONTRACT AGREEMENTThe contract agreement is the agreement between the client and the contractor which has to be followed by the contractor during the working of the project. It includes various specifications, rules, references to the IS codes, and different agreement acceptance from the contractor,

Some of the sub-headings of contract agreement are as follows:

● Volume-1

▪ NIT (Notice Inviting Tenders)

▪ ITT (Instructions to tenders)

▪ FOT (Form of tender)

● Volume-2

▪ GCC (General Condition of contract)

▪ SCC (Special Condition of contract)

● Volume-3

Employer’s Requirements

● Volume-4

Design Basis Report

● Volume-5

Technical Specifications

DESIGN

REFERENCE IS CODESIS 456-2000

Plain and Reinforced Concrete - Code of Practice is an Indian Standard code of practice for general structural use of plain and reinforced concrete. The latest revision of this standard was done in year 2000, reaffirmed 2005. This code uses the limit state design approach. It is written for use in India. It gives extensive information on the various aspects of concrete. IS 456 is considered as the Bible for Civil Engineers in India.

It contains five sections and eight annexures:

● Section 1: General

● Section 2: Materials, Workmanship, Inspection and Testing

● Section 3: General Design Considerations

● Section 4: Special Design Requirements for Structural Members and Systems

● Section 5: Structural Design (Limit State Method)

IS-1893(Part 1):2002

CRITERIA FOR EARTHQUAKE RESISTANT DESIGN OF STRUCTURES

PART 1 General provisions and Buildings

This standard contains provisions that are general in nature and applicable to all structures. Also, it contains provisions that are specific to buildings only. It covers general principles and design criteria,

combinations, design spectrum, main attributes of buildings, dynamic analysis, apart from seismic zoning map and seismic coefficients of important towns, map showing epicenters, map showing tectonic features and lithological map of India.

SP-34

HANDBOOK ON CONCRETE REINFORCEMENT AND DETAILING

▪This Handbook provides information on properties of reinforcing steel and detailing requirements, including storage, fabrication, assembly, welding and placing of reinforcement in accordance with IS : 456-1978. As a result of the introduction of limit state method ‘of design for reinforced concrete structures and the concept of development length, detailing has become extremely important as many of the design requirements are to be’ met through detailing. This Handbook is expected to guide the designer in detailing which include correct positioning of bare for a particular type of structural element and preparation of bar bending schedule.

IS 13920:1993

INDIAN STANDARD

DUCTILE DETAILING OF REINFORCED CONCRETE STRUCTURES SUBJECTED TO SEISMIC FORCES — CODE OF PRACTICE

● This standard covers the requirements for designing and detailing of monolithic reinforced concrete buildings so as to give them adequate toughness and ductility to resist severe earthquake shocks without collapse.

● Provisions of this code shall be adopted in all reinforced concrete structures which are located in seismic zone III, IV or V.

● The provisions for reinforced concrete construction given herein apply specifically to monolithic reinforced concrete construction. Precast and/or prestressed concrete members may be used only if they can provide the same level of ductility as that of a monolithic reinforced concrete construction during or after an earthquake.

IS 2911-1984

INDIAN STANDARD CODE OF PRACTICE FOR DESIGN AND CONSTRUCTION PILE FOUNDATIONS PART I CONCRETE PILES

Section I Driven Cast in-Situ Concrete Piles

● This standard covers the design and construction of reinforced concrete driven cast in-situ load-bearing piles which transmit the load of a structure to the soil by resistance developed at the toe of the piles by end bearing or by friction along their surface or by both.

● This standard does not cover the use of driven cast in-situ piles for any other purpose, for example, temporary or permanent retaining structure, etc.

DESIGN BASIS REPORTThe Design Basis Report of a particular part of construction, for example, elevated station defines the structure design assumption of elevated station from foundation to top.

It mainly deals with the structural issues viz design of substructure , design of super structure, various types of loading applicable on them , load combination etc. In it, the various values of various parameters are fixed so as the design will be the best for serviceability and strength criteria.

● STRUCTURAL ISSUES

▪ CONCRETE

◦ Young’s modulus is given by the formula Ec =5000(fck).5

◦ Modular ratio is to be taken as 10.

◦ The density is to be taken as 25 KN per m3 for reinforced concrete

And 24 KN per m3 for plain concrete.

◦ Poisson’s ratio is to be taken as 0.15.

◦ The coefficient of thermal expansion is to be 1.17 X 10-5 per ◦C.

▪ STRUCTURAL STEEL

◦ It is used for roof portals, steel staircase, foot bridges, purlins, railing, supporting utilities, coverings etc.

◦ Two types of steel are used

- Hollow steel which can be either rectangular or circular- Steel for concrete structure purpose

◦ The Young’s modulus for structural steel is equal to 2 X 105 MPa

◦ The density is equal to 78.5 KN per m3 .

◦ Poisson ratio for structural steel is 0.3

◦ The coefficient of thermal expansion is to be 1.2 X 10-3 per ◦C.

◦ For Hollow steel

- Tensile strength = 450 MPa- Yield strength = 310 MPa

◦ For Structural Steel

- Tensile strength = 410 MPa- Yield strength = 250 MPa t<20

240 MPa 20<t<40

230 MPa t>40

▪ REINFORCED BARS

◦ Grade of the steel is Fe500 D.

◦ Young’s modulus for reinforced bars is equal to 2 X 105 MPa.

◦ The density is equal to 78.5 KN per m3 .

◦ The characteristic strength is 500 MPa.

◦ The standard diameter of bars varies from 8 to 36mm.

● HORIZONTAL CLEARANCE

◦ The distance between center of the track and platform is 1670mm.

◦ Center to center distance between two tracks is 4100mm.

● VERTICAL CLEARANCE

◦ Minimum plinth thickness is 195mm.

◦ Top of rail to top of platform is 1.09m.

◦ Top of rail to top of plinth is 2.19m.

● CLEARANCE FOR PASSENGERS

◦ 3.30m of clear height is to be provided on concourse level.

● DESIGN LOADS

The design horizontal seismic coefficient Ah for a structure shall be determined by the following expression:

Ah = ZISa/2Rg

Provided that for any structure with T <0.1 s, the value of A will not be taken less than Z/2 whatever be the value of I/R

Where

Z = Zone factor, is for the Maximum Considered Earthquake (MCE) and service life of structure in a zone. The factor 2 in the denominator of Z is used so as to reduce the Maximum Considered Earthquake (MCE) zone factor to the factor for Design Basis Earthquake (DBE).

I = Importance factor, depending upon the functional use of the structures, characterized by Hazardous consequences of its failure, post-earthquake functional needs, historical value, or economic importance.

R = Response reduction factor, depending on the perceived seismic damage performance of the structure, characterized by ductile or brittle deformations. However, the ratio (I/R) shall not be greater than 1.0.

Sa/g = Average response acceleration coefficient, is based on appropriate natural periods and damping of the structure. These curves represent free field ground motion.

● BASIC LOAD COMBINATION

Load factors for plastic design of steel structures

In the plastic design of steel structures, the following load combinations shall be accounted for:

1) 1.7(DL+ IL)

2) 1.7(DL± EL)

3) 1.3(DL+ IL ± EL)

DETAILED DRAWINGThe designing section also works on detailed drawing of pile foundation, pile cap, pier. These detailed drawing helps in easy, systemic, and fast progress of the project. These drawing also includes notes which gives us the idea about the authenticity of the drawing as these notes are directly linked to the IS codes which are the sole authentic documents for any design of structures. These drawing are drawn using the software like AUTOCAD. Some of the examples of drawing are as under:-

● REINFORCEMENT DETAILS OF PIER P94 TO P95

● REINFORCEMENT DETAILS OF PILE CAP FOR PIER P27

●

DETAILS OF PILE FOUNDATION FOR PIER

● CROSS SECTION OF STANDARD PIER

STRETCH ‘B’ One Elevated Ramp and Three Elevated stations namely Mayapuri, Rajouri Garden and E.S.I Hospital in the Mukundpur-Yamuna Vihar Corridor

PILING

A pile is relatively small diameter shaft, which is driven or installed into ground by suitable means. The piles are usually driven in groups to provide foundation for structure. The pile groups may be subjected to vertical loads, horizontal loads or a combination of vertical and horizontal loads. Piles are useful in transferring load through poor soil or water to a suitable bearing stratum. Piles are also used to resist horizontal loads as in the case of foundations for retaining walls, bridges, abutments and wharves. In case of large lateral loads piles are also driven at angles. Piles are sometimes used to resist uplift loads and thus are in tension. Piles can also be used to provide anchorage against horizontal pull. Piles may be required to increase the stability of tall structures, where the foundations are subjected to large eccentric loads, inclined loads and moments. They arealso used to avoid damage due to the possible scouring of the soil immediately below the foundation.

TYPES OF PILESPiles are classified using different criteria:▪ Material of construction: timber, steel, concrete composite piles.

▪ Cross-section: circular, square, hexagonal, H-section, I-section etc.

▪ Shape: cylindrical, tapered, under reamed etc.

▪ Mode of load transfer: bearing, friction, tension etc.

▪ Method of forming: precast, pre-stressed, cast in situ etc.

▪ Method of installation: driven, bored, vibrated, jetted etc.

REQUIREMENTS AS PER CONTRACT CC- 28

TOLERANCE

▪For the pile, Displacement from center should not exceed 10mm or one tenth the diameter of the pile whichever is lesser▪Maximum allowable misplacement is 15mm ▪Surface irregularity should be less than 5mm ▪Variation of top point should be less than 25mm

CONCRETE PILES

The piles should be cast as per IS2911 provisions with minimum reinforcement as per code unless specified.

REINFORCEMENT

▪ should be pre-assembled and wired into position by using bending wire. ▪Clear cover to outermost reinforcement should be 75mm.▪Minimum Lap Length Shall be 47.5 times the dia. of smaller bar.▪Lap shall be suitably staggered and minimum c/c distance between adjacent laps shall be 1.3 times lap length.▪There are two types of concrete piles:◦ Precast Piles◦ Cast-in Situ Piles: Only cast-in piles were provided at the site. The contract specifications for this have been discussed as follows.

CAST IN SITU PILES

▪ During the boring, samples should be taken and sent to the lab for testing or in-situ tests should be carried out▪ Dimension of the pile should not be less than that specified. When an enlarged base is provided, it should be concentric.▪ Adequate temporary casing can be provided for ensuring stability near the ground. It should be backfilled if rapid loss of drilling fluid occurs. The temporary casing should be free from projections and distortion during concreting.▪ After concreting of the pile, the empty bore hole should be backfilled.

CONCRETING

▪The workability of the concrete should be such that a continuous monolith shaft of full cross-sections formed. No contamination of concrete is allowed▪It should be ensured that mix and placing of concrete does not result in arching▪Concrete under water or drilling fluid should be poured through tremmie as per IS 2911.Hopper and pile of the tremmie should be clean and watertight.▪At all times, tremmie should penetrate the previously prepared concrete so as to prevent contact with the drilling fluid. Sufficient quantity of concrete should be maintained in the pipe so that pressure exceeds that of the fluid.▪Internal diameter of the pipe should not be less than 200mm for concrete with max. Size of aggregate 20mm.

DRILLING FLUID

On the site, Polymer is used as opposed to bentonite slurry as specified in the contract document. Some of the benefits of this polymer is:i. Eco-Friendlyii. Results in a neat and clean concrete surfaceiii. The calcium present in concrete kills the Polymud this reducing the contamination of the concrete. With Polymud only top 20cm of concrete is wasted as opposed to 1m concrete wasted if bentonite slurry is used.

PILE TESTING

Pile should be tested as per IS: 2911-Part IV. Following tests are carried out at the site:● Pile Integrity Tests● Cross Hole Test

STEPS:

Bored cast in situ piles are constructed in the following sequence:

1. Survey: The surveyor set out the center of the bored pile location using total station.2. Utility diversion: A circular pit of diameter 1700mm and depth 1500 mm shall be manually excavated at the location to ensure that the utilities are present.

3. Checks for Pile vertically and position: During the process of boring following checks should be made: i. Check the verticality of the casing during installation by plumbing from two perpendicular directions.ii. Check of the eccentricity of the borehole after installation of casing. If the eccentricity is more than 50mm then reinstallation is done.iii. The verticality of the casing is checked continuously until the toe is reached and is kept within a tolerance of 50mm.

4. Boring of soil is carried by using hydraulic boring machine.

5. Installation of temporary casing to stabilize the upper bore, a temporary steel casing of length 2.5- 3m is installed:i. A 1000mm diameter hole is drilled using hydraulic boring machine up to a depth of 3-4m.ii. The casing should then be lowered in the hole with the help of a crane.iii. The casing is then driven in to the ground with the help of a rotatory machine until about 300mm is left above the ground. The rig is then used to progress the excavation to the bottom of the casing pipe and then suitable polymer system is added before further excavation.iv. Polymer system should be added continuously during excavation.

6. Cleaning of base:i. Boring is stopped when the toe of the pile level is reached. The borehole is cleaned carefully and the soil is removed.ii. The depth is checked before the lowering of the cage.

7. Fabrication and installation of reinforcement cage: Cutting and bending of bars shall be carried out with approved schedule in fabrication yard or on the site.Tie wires shall be used for binding the bars. Circular concrete spacers shall be provided of the same grade of the pile. Vertical distance between each layer of spacers shall be 4m.

CONCRETING (STEPS):●Grade M35 concrete shall be supplied from batching plant. All concrete delivered shall be visually inspected and checked against delivery note before being tested and used. ●Concrete shall be placed using pipes. The pipes (200/ 250mm dia. pipes) are threaded 100mm deep both at the lower end (threading inside) and the upper end (threaded outside).●Pipes are joined towards into the hole. The end of the pipe should not be more than 300 m above the bottom of the pile to ensure that free fall of concrete shall not be more than 1.5m.●The concrete shall be discharged from the delivery truck to a hopper connected to the pipes. As the level of the concrete in the borehole rises, these shall be withdrawn accordingly to aid the flow of concrete.

PILE CAP

PILE CAP

METHODOLOGY

Excavation of Pile Cap Area:-

Excavation of Pile Cap will be done as per the size of pile cap (including working space1m approx.) on all sides up to the depth of pile cap. The excavation will be done by the JCB. The sides of pit will be made sloped or stepped to avoid sliding.

Reinforcement:

BBS shall be prepared as per approved drawings and jointly checked. The reinforcement bars cut and bent to the required length and shape shall be manufactured either on site or pre-arranged at steel yard, placed and tied in position as per the applicable specifications. The reinforcement of Pier also shall be fixed in position. Reinforcement cage to overall dimensions will be fixed exactly true to the plumb line and specified plan geometry.

Fixing of side form work:

The shutters are applied with shuttering oil. The shutters shall be aligned (Both Horizontally and vertically within the specified limits) and fixed in position with the help of Tie-rods. The joints between the shutters shall be closed by suitable putty or by use of sponge. Proper staging etc. shall be erected for fixing and keeping in position reinforcement bars in position.

Setting out:

After completion of pile cap form work, top of foundation level shall be marked and jointly checked with DMRC for approval. The layout of pier as per “Approved Drawings” shall be marked on the top of the cap for the inspection of DMRC

Concrete Placing:

M35 Grade of concrete is used for Pile cap Concreting shall be carried out as a single pour in layers of 300mm thickness. The batching plant which is already established at site (30cum/ hr. and 60cum/hr. capacity) and calibrated shall be used for production of concrete. All necessary formats/ reports as per approved QA/QP shall be fulfilled. The Concrete shallbe transported by transit mixers. Concrete shall be placed in layers of 300mm thick as per any other approved method.Concrete shall be well compacted using vibrators. The top surface of concrete shall be properly finished with the side slopes as specified in the drawings.

Precautions while concreting:

Height of fall shall be restricted to less than 1.5m.For the purpose of inserting concrete hose in to the reinforcement cage.Vibrators shall be used sufficiently to produce dense concrete. To avoid segregation, excessuse of vibration shall be restricted.

De-shuttering:

De-shuttering shall start only after 24hours of completion of concreting which depends on the condition of the concrete setting. Care shall be taken to avoid damages to edges of concrete. Any major damage of concrete shall be repaired after proper notification to DMRC.

PIER

METHODOLOGY

PURPOSE:

This method statement deals with the construction processes of Piers, which directly affect the quality and planning. This Method statement deals

with the materials to be used, and the necessary equipment to be deployed in the construction of pier

DESIGN AND DRAWINGS:

The Pier shall be constructed as per the dimensions and locations indicated in the Approved drawings& based on that the separate bar bending Schedule (BBS) for each different height’s Pier shall be prepared. Latest revision of GFC drawing shall be followed.

MATERIALS:

All materials have been used shall comply all quality assurance and quality manual specification and technical specification of tender document. Suitable Mix Design as per Grade of concrete shall be got approved by DMRC in advance before concreting operation.

Cement:

The cement used as per grade of concrete shall be offollowing type: 53 grade Ordinary Portland cement conforming to IS 12269.

Aggregates:

Aggregates fro, natural source shall in accordance with IS 383. Aggregates shall be stored on paved area in batching plant according to nominal size.

Water:

Water shall be used for concreting as well for curing shall be portable and free from deleterious materials. Water used for mixing and curing concrete shall not be acidic in nature and free from chemicals and organic impurities.

Admixture:

Polypropylene Fiber and Glenium Ace 30T are used as a add mixture

FIXING OF DRAINAGE SPOUT:

Drainage shall be provided as per issued GFC drawing. HDPE Pipe of 200 dia. Drainage pipe will be fixed manually at pier center as per drawing. The pipe shall be secured at location by using rebar of 16mm diameter as holders.

FIXING OF PIER SIDE FORMWORKS:

Pier reinforcement shall be tied up the full height. The arrangement of shuttering shall be followed as per design arrangement as shown in enclosed drawing on page. Each side shutter shall be first assembled on ground for the full height of the pier. Shutter shall be entire cleaned and shutter oil should be applied with the help of brush. Joints of formwork shall be slurry tight. The center line of the pier shall be checked with the help of total station. Verticality of shutter shall be maintained throughout the pier concreting operation which shall be supervised by using hanging plum-bob on three sides of shutter.

PIER’S CONCRETING OPERATIONS:

●Concreting & Survey of Pier Starter:-

After casting of pile cap the four reference point will be taken around pier cage. The area of concrete under the pier shall be cleaned for all laitance / loose concrete. The pier shape shall be marked and a starter of 0.6 m height approx. shall be cast with a steel formwork exactly the same as the pier shutter. It helps to maintain the trueness of pier location at position with controllable base. Level of starter shall be checked for its correctness before pouring. Base of shutter shall be fully slurry tight to avoid any slurry leakage during concreting operation.

●Concrete of Pier Shaft: - Grade of concrete-M50. A hose pipe/ stationary pump pipe of 200mm diameter shall be installed up to a depth of 250-300 mm above the starter top. Proper vibrations shall be done with the help of vibrator. The concrete shall be placed with the help of either stationery concrete pump or boom placer. Before starting of concreting all checklists shall get signed jointly with DMRC Representative and sufficient standby arrangement for pouring of concrete shall be made available before start of concrete for incase

failure of concreting pump during operation. Pier Concreting shall be carried out as a single pour in suitable intervals. Pouring shall be slow as desired to maintain stability of formwork due to jerk. i.e 80-120mm.

●Precautions while concreting:

▪Height of free fall shall be restricted to less than1.5m. ▪Vibrators shall be used sufficiently to produce dense concrete to avoid segregation, excess use of vibration.

DE-SHUTTERING OF FORMWORK:

De-shuttering shall start only after 24hours of completion of concreting which depends on the condition of the concrete setting. Care shall be taken to avoid damages to edges of concrete. Any major damage of concrete

shall be repaired after proper notification to DMRC.

PIER CAP

METHODOLOGY

Survey:

After casting of pier, the center line shall be marked over the top surface of pier to fix the formwork and reinforcement. Pier Cap co-ordinates will be jointly checked prior to casting.

Reinforcements:

BBS shall be prepared as per approved drawings and jointly checked. The reinforcement bars cut and bent to the required length and shape shall be manufactured either on site or pre-arranged at steel yard, placed andtied in position as per the applicable specification. Reinforcement cage to overall dimensions will be fixed exactly to the GFC drawing.

Concreting:

The concrete of M50 grade shall be prepared in the centralized batching plant as per approved mix design. The concrete shall be transported in transit mixers to the pouring location. The concreting shall be done using Concrete Boom Placer with flexible hose. The compaction of concrete shall be done using vibrator. To check the quality of concrete, cubes shall be taken for testing compressive strength as per IS: 456-2000 at pouring locations.

De-shuttering:

After 24 hour of concreting side shutter shall be de-shuttered. De-shuttering will be done using crane and taking all the safety measures.

Curing:

After removal of side formwork the surface of entire pier cap shall be wrapped with Hessian cloth, which shall be kept moist by sprinkling the water at regular interval and care shall be taken that hessian cloth never gets dried.

CASTING YARD

The casting yard brings factory- controlled production techniques, efficiency, quality control, and time savings to bridge construction. Due to the required number of segment, a casting yard to this Project has been able to be installed not far from erection site, Near Ashok Park Metro Station, Zakhira.

Two methods of segment casting are available. These are:-

1. Long Line Casting2. Short-Line Casting

Long Line Casting: Casting segments on a casting bed of sufficient length to permit the cumulative casting of segments for the entire length of a span or cantilever between field closure pours without repositioning the segments on the casting bed. With this method, the first segment is cast between bulkheads and successive segments are cast between amovable bulkhead on one end and the previously cast segment on the other.

Short Line Casting: Casting segments one at a time in a casting cell between a bulkhead at one end and a previously cast segment at the other.

The first segment is cast between the bulkhead and another, temporary bulkhead.

CASTING OF SEGMENT First, segment reinforcement is assembled on casting bed. After a first control, shuttering of reinforcement cage is installed in the casting form by means of tower crane. After shuttering, concrete is placed into the mould by bloom placer and mould is allowed for setting up according to its geometry, after initial setting of concrete in mould the formwork is removed by means of tower crane and segment is allowed for curing. After curing, casted segment is shifted nearby the form in order match the next segment to be concreted. Here below Picture presents the typical casting sequence for segment prefabrication using match casting

Match Cast: A precast concrete fabrication process whereby aSegment is cast against the preceding segment producing a matching interface which permits the re-establishment of the cast geometry at erection time. Match casting is accomplished by either the short line or long line casting method

QUALITY ASSURANCE& QUALITY CONTROL DEPARTMET

Quality is the key component which propels performance and defines leadership traits. At L&T Construction, Quality Standards have been internalized and documented in Quality Assurance manuals. L&T Construction recognizes the crucial significance of the human element in ensuring quality. Structured training programmes ensure that every L&T employee is conscious of his/her role and responsibility in extending L&T Construction’s tradition of leadership through quality.

TESTS ON CEMENT CONSISTENCY:

AIM: To determine the quantity of water required to produce a cement paste of standard consistency as per IS: 4031 (Part 4) - 1988.

PRINCIPLE: 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 7mm from the bottom of the Vicat mould.

APPARATUS: VICAT APPARATUS, Vicat apparatus conforming to IS: 5513 - 1976 Balance,

PROCEDURE:

▪ Weigh approximately 400g of cement and mix it with a weighed quantity of water. The time of gauging should be between 3 to 5 minutes

▪ Fill the Vicat mould with paste and level it with a trowel.

▪ Lower the plunger gently till it touches the cement surface.

▪ Release the plunger allowing it to sink into the paste.

▪ Note the reading on the gauge.

▪ Repeat the above procedure taking fresh samples of cement and different quantities of water until the reading on the gauge is 5 to 7mm.

REPORTING OF RESULTS:

Express the amount of water as a percentage of the weight of dry cement to the first place of decimal.

INITIAL AND FINAL SETTING TIME

AIM: To determine the initial and the final setting time of cement as per IS: 4031 (Part 5) -1988.

APPARATUS: Vicat apparatus conforming to IS: 5513 - 1976

PROCEDURE:

▪ Prepare a cement paste by gauging the cement with 0.85 times the water required to give a paste of standard consistency  

▪ Start a stop-watch, the moment water is added to the cement.

▪ Fill the Vicat mould completely with the cement paste gauged as above, the mould resting on a non-porous plate and smooth off the surface of the paste making it level with the top of the mould. The cement block thus prepared in the mould is the test block.

▪ INITIAL SETTING TIME-Place the test block under the rod bearing the needle. Lower the needle gently in order to make contact with the surface of the cement paste and release quickly, allowing it to penetrate the test block. Repeat the procedure till the needle fails to pierce the test block to a point 5.0 ± 0.5mm measured from the bottom of the mould. The time period elapsing between the time, water is added to the cement and the time, the needle fails to pierce the test block by 5.0 ± 0.5mm measured from the bottom of the mould, is the initial setting time.

▪ FINAL SETTING TIME-Replace the above needle by the one with an annular attachment. The cement should be considered as finally set when, upon applying the needle gently to the surface of the test block, the needle makes an impression therein, while the attachment fails to do so. The period elapsing between the time, water is added to the cement and the time, the needle makes an impression on the surface of the test block, while the attachment fails to do so, is the final setting time.

The results of the initial and the final setting time should be reported to the nearest five minutes.   

TESTS ON AGGREGATES SIEVE ANALYSIS

AIM: To determine the particle size distribution of fine and coarse aggregates by sieving as per IS: 2386 (Part I) - 1963.

PRINCIPLE:

By passing the sample downward through a series of standard sieves, each of decreasing size openings, the aggregates are separated into several groups, each of which contains aggregates in a particular size range.

APPARATUS:

A SET OF IS SIEVES

i) A set of IS Sieves of sizes - 80mm, 63mm, 50mm, 40mm, 31.5mm, 25mm, 20mm,16mm, 12.5mm, 10mm, 6.3mm, 4.75mm, 3.35mm, 2.36mm, 1.18mm, 600µm,300µm, 150µm and 75µm

ii) Balance or scale with an accuracy to measure 0.1 percent of the weight of the tests ample

PROCEDURE:i) The test sample is dried to a constant weight at a temperature of 110

+ 5oC and weighedii) The sample is sieved by using a set of IS Sieves. On completion of sieving, the material on each sieve is weighed.iii) Cumulative weight passing through each sieve is calculated as a

percentage of the total sample weightiv) Fineness modulus is obtained by adding cumulative percentage of

aggregate s\retained on each sieve and dividing the sum by 100.   

REPORTING OF RESULTS: The results should be calculated and reported as

i) the cumulative percentage by weight of the total sampleii) the percentage by weight of the total sample passing through one

sieve and retained on the next smaller sieve, to the nearest 0.1 percent.

TESTS ON FRESH CONCRETE SLUMP

AIM: To determine the workability of fresh concrete by slump test as per IS: 1199 - 1959.

APPARATUS: i) Slump cone ii) Tamping rod

PROCEDURE:

i) The internal surface of the mould is thoroughly cleaned and applied with a light coat of oil.

ii) The mould is placed on a smooth, horizontal, rigid and non- absorbent surface.

iii) The mould is then filled in four layers with freshly mixed concrete, each approximately to one-fourth of the height of the mould.    

iv) Each layer is tamped 25 times by the rounded end of the tamping rod (strokes are distributed evenly over the cross- section)

v) After the top layer is rodded, the concrete is struck off the level with a trowel.

vi) The mould is removed from the concrete immediately by raising it slowly in the vertical direction.

vii) The difference in level between the height of the mould and that of the highest point of the subsided concrete is measured.

viii) This difference in height in mm is the slump of the concrete.

REPORTING OF RESULTS:

The slump measured should be recorded in mm of subsidence of the specimen during the test. Any slump specimen, which collapses or shears off laterally gives in correct result and if this occurs, the test should be repeated with another sample. If, in the repeat test also, the specimen shears, the slump should be measured and the fact that the specimen sheared, should be recorded.

BATCHING PLANT

When bagged cement is used, the field mix proportions are usually given in terms of designated amounts of fine and coarse aggregate per bag of cement. The amount of material that is mixed at a time is called a batch. The process of weighing out or measuring out the ingredients for a batch of concrete is called batching. When mixing is to be done by hand, the size of the batch depends upon the number of persons available to turn with hand tools. When mixing is to be done by machine,the size of batch depends upon rated capacity of the mixer. On large jobs, the aggregate is weighed out in an aggregate batching plant or batch plant. Whenever possible a batch plant is located near to and used in conjunction with a crushing and screening plant. The batch plant may include separate hoppers for several sizes of fine and coarse aggregates, or only one hopperfor fine aggregate and another for coarse aggregate. It may have one or more divided hoppers, each containing two or more separate compartments for different sizes of aggregates. Each storage hopper or storage hopper compartment can be discharged into a weigh box, which can, in turn be discharged into a mixer or a batch truck. When specific weight of aggregate is called for, the operator sets the weight on beam scale.

IMPORTANCE OF A CONCRETE BATCHING PLANT

A concrete batching plant is a facility where the ingredients of concrete are mixed and blended skill fully. Once the quality concrete is prepared it is transported to the site on A truck with a revolving drum which is known as transit mixer. The concrete produced out of the concrete batching plant is used in the foundations of building construction, paving materials for roads, plumbing and piping in construction projects etc. So, from this we can make out that how important is the use of concrete in construction equipment. Concrete batching plant is used to mix and blend cement, water, sand and aggregates to form quality concrete without which building any construction project is not possible. It becomes necessary that the concrete batching

plant is efficient and speedy in order to complete a construction project as soon as possible. The durability of a construction project highly depends on the quality of the concrete used in that construction project. So, if werequire a concrete batching plant for our construction project, then we need to select with lot of precision as the success and failure of our construction project depends on the concrete used which is produced by a concrete batching plant.

TRANSIT MIXERS:The capacity of transit miller used is 6 cubic met. A Transit Mixers a truck or trailer with a rotating drum which mixes and blends the concrete while on transit. The transit mixer is very much beneficial for the construction sites which require prompt delivery of freshly mixed concrete. Basically, there are two types of transit mixers, truck mounted transit mixers and trailer mounted transit mixers. When the drum in the transit mixer rotates clockwise, the concrete is being prepared and when it rotates anti clock-wise, it pours the concrete out of the drum

Erection

The superstructure is be erected entirely from below using an over slung Erection tackle. In Project CC-28 we are using over slung launching girder (LG).

Launching girder can be used for both balanced cantilever as well as for span-by-span erection. Depending on the project dry joint or wet joint erection is required. On the basis of working launching girder. It is classified into different part as follow.

Auto-Launching ● Segment Assembly ● gluing & stressing

VARIOUS TERMS USED IN ERECTION –

MACALLOY BAR-

Macalloy bar systems are ideal for economic application of post- tensioning forces on relatively short tendons. Through the use of threaded connections and anchorages they are simple to use and tend themselves to many applications.

CRAB -

The Crab carries the hoist across the bay along the double girder bridge, traversing the span.One or more hoist can be used on one or more Crabs.

Hoist-

The Hoist is mounted to the carriage or crab, and platforms the actual lifting function via a hook or lifting attachment. There are two basic types of hoist. The first is the Wire Rope Hoist which is generally for Higher Capacities and faster lifting speeds. The second is Chain hoist which are less expensive and used for lower capacities.

UNDER SLUNG-

The crane Bridge travels on the bottom flange of the gantry beams which are usually supported by the roof structures or a Goal-post structure.

OVER SLUNG-

The crane bridge travels on top of rails mounted on gantry beam supported by either the building columns or support columns specifically engineered for the crane.

HSFG BOLTS-

Also called as High Strength Friction Grip bolts. Due to high tensile strength these are commonly used in connections which require the taking up of high flexure and the tensile stress generated could be readily resisted by its high tensile strength. These are used where any tight slip movement would render the integrity of the whole structures break down.

SPLICE PLATE-

A Splice Plate is a thick metal sheet used to reinforce the connection between structural steel beams. The joint between two pieces of steel is known as a Splice, and each splice must be carefully reinforced to ensure a secure bond. Adding a splice plate minimizes the risk of failure and helps improve safety for building occupants.

LAUNCHING

STEP – 1

▪ Erect the HD tower and temporary tower as shown in fig.

▪ Erect the middle support over the temporary tower.

▪ Erect the front support over the pier and engage anchor bolts as shown.

▪ Place S1 box of LG on front support and HD tower at its exact location.

▪ Place S2 & S3 box in sequence and connect the box.

▪ S1 to s4 to each other by HSFG bolts and splice plates.

▪ Place box S4A and connect the box s4A to box s4 by HSFG bolts and splice plates.

STEP-2

▪ Erect the crab hoist, bracket for monojack, sliding beam and 47tonn counter wt. over LG.

▪Remove all the HD tower between the front and middle support.

STEP-3

Erect the span P69-70

STEP-4

▪Remove the counter weight.

▪Erect the rear support over segment S3 of newly erected span.

▪Transfer the load to rear support so that middle support is free.

▪Anchor rear support on top of segment S3 with vertical stress bars and jack it to transfer min load of 10T.

STEP-5

▪Remove the middle support from temporary tower.

▪Erect the middle support over segment S1 of newly erected span near

front support

▪Transfer the load to middle sup so that front support is free.

▪Anchor middle support on top of segment S1 with vertical stress bars and jack it to transfer min load of 10T.

▪Move the slider beam over rear support as shown

▪Remove the temporary tower.

STEP-6

▪Close the telescopic leg of front support with the help of chain pulley blocks.

STEP- 7

▪Start the auto-launching.

▪Auto launch the girder by 9250mm.

STEP-8

▪Move the slider beam towards rear side by 12500 as shown so that it comes over S4A box.

▪Erect LG box S5 over the HD tower and connect the box S5 with box S4A by tightening the HSFG bolts with splice plates.

STEP-9

▪Start the auto launching and auto launch the girder by 6750 as shown.

▪Pull back the slider after every stroke.

STEP-10

▪Start the auto-launching and auto launch by the girder 2500.

STEP-11

▪Place the LG box S6 over the HD tower and connect the box S6 with box S5 by tightening the HSFG bolts with splice plates.

▪ Move the slider beam towards rear side by 7500.

STEP- 12

▪Further auto launch and launching girder by 4500.

STEP 13

▪Erect the 65tonn counter weight on LG box S6.

STEP-14

▪Further auto-launch and launching girder by 4750.

STEP-15

Place LG box S7 over the HD tower and connect the box S7 with box S6 by HSFG bolts with splice plates.

STEP-16

▪Start the auto-launching and auto-launch the girder until front support reaches its final position.

STEP -17

▪Open the front support leg and anchor the front support on pier cap.

▪ Erect the final counter weight over S7 box.

▪Erect the span.

STEP-18

▪Remove monorail from S7 box and cut 3500mm from S6 box also from rear end.

▪Erect the rail over span erected span near rear trolley.

▪Erect the rear trolley over segment S1, S2 and anchor it with superstructure.

STEP-19

▪Lower the jack of rear support so that load come over the rear trolley.

▪Anchor the rear trolley with superstructure.

▪Move the rear support from segment S3 (rear side) and move it to the segment S3 near middle support and activate it.

▪Deactivate the middle support.

STEP-20

▪Move the middle support from segment S1 (rear side) and shift it to segment S3 (near front support) and activate it.

▪Move the rear support from segment S3 (rear side) and shift it to the old position of middle support and activate it.

STEP- 21

▪Move the middle support from segment S3 (rear side) and shift it to the segment S1 near front support and activate it.

▪Close the telescopic leg of front support with the help of chain pulley block.

STEP- 22

▪Remove the HD tower.

▪Start the auto-launching and launch the girder by 6900.

▪Fix the rear trolley with LG to its final position.

SEGMENT ASSEMBLY & STRESSING

STEP-1

▪Move 11 sliding beam towards front support as shown.

▪ Move 2 sliding beam towards the counter weight as shown.

STEP – 2

▪ Lift the pier segment S1 with the help of lifting device.

STEP- 3

▪ Hang the segment SE1 by vertical suspension over sliding beam.

▪ Remove the lifting device with lifting beam from segment SE1.

▪Move segment over pier by sliding beam and position it on.

STEP-4

▪Stop the trailer below the span and fix lifting beam & temporary prestressing beam on segment SE2J.

▪Lift the segment SE2J with the help of lifting device.

STEP-5

▪Hang the segment SE2J by vertical suspender over sliding beam.

▪Remove the lifting device with lifting beam from segment SE2J.

▪Move the segment SE2J by sliding beam near segment SE1.

▪Follow same procedure for segment SE3I, SE4H, SE5G, SE5F.

STEP- 6

▪ Hang the segment SE1A by vertical suspender over sliding beam.

▪ Remove the lifting device with lifting beam from segment SE1A.

▪Move the segment SE1A over pier by sliding beam and position it near front support as shown.

▪ Lift the segment SE2B, SE3C, SE4D, SE5E same as above.

▪ Lift the segment SE3C by suspender bar so that the segment is parked over segment SE2B as shown.

STEP-7

.▪Shift the segment SE2J to SE4D towards front support so thst minimum 300mm gap to be created between segment SE1 and SE2J.

▪ Create 300mm gap between SE1 & SE2J for applying epoxy glue between segment.

STEP-8

▪Do temporary prestressing of the segment SE1 And SE2J by stress bars.

▪ Repeat the same steps for remaining segment upto SE4D.

▪ Parking segment SE3C will come down.

▪ Do temporary prestressing of the segment SE4D and SE3C.

STEP-9

▪Insert prestressing tendons and install the anchors.

▪Do prestressing of cables.

▪Activate temporary bearing (hydraulic jack with lock nut and tilting saddles)

RISK INVOLVED:

a. Traffic plying on road at all points of conflict with.

b. Working at Height.

c. Trespassing of other workers in the working zone.

d. Working with heavy Equipment.

SAFETY PRECAUTIONS:

a) Proper barricading should be done with suitable traffic signs (warning signs diversion signs) to avoid any vehicles on the road encroaching in to the working area.

b) The Equipments will be operated by competent persons & within the safe working radius/limits and all the equipments will be properly

maintained and checked. No personnel will be allowed in the area of working/swing radius of the crane and other equipment.

c) All slings, deshackles, rope, master ring shall be checked and verified.

d) Work permit shall be issued by competent person.

e) Cranes will be setup on firm ground with wooden log and thick metal plate underneath of outriggers.

f) Trial tandem lift at required boom length and radius needs will be carried out before performing lift operation.

g) Both cranes will have cut off device / sensor to prevent overloading during lifting operation.

h) All workers would be made aware regarding the methods of work and safety awareness through toolbox talks.

i) Employing safe working practices by the concerned Engineers, foreman & supervisory staff.

j) Unauthorized / outside persons will not be allowed to enter inside/near during the erection of girders and at the time of test.

k) All the workers will be provided with necessary PPE‟s & other safety equipment.

l) Availability of site First Aid facilities.

m) Proper Lighting arrangement during the night.

n) Experienced Safety officer and team will be deployed to ensure that erection shall be carried in safe condition.

o) Safe access will be provided in the form of Stair case which is erected for the safe access during the launching operations.

p) Formal Risk assessment will be conducted and the suitable control measures will be identified and adopted.

CONCLUSION

It was a wonderful learning experience at L&T Construction site of Project CC-28 for one month in New Delhi. I gained a lot of insight regarding almost every aspect of site. I was given exposure in almost all the departments at the site. The friendly welcome from all the employees is appreciating, sharing their experience and giving their peace of wisdom which they have gained in long journey of work. I hope this experience will surely help me in my future and also in shaping my career.

REFERENCES

● http://en.wikipedia.org/ (for Batching Plant and introduction)● All the relevant IS Codes as specified in the Design Report● Contract Agreement CC-28● All the relevant Method Statements as specified● Various Internet sources for introduction about piling and launching Segments.