Post on 14-Feb-2017
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2013
L&T construction project
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Report on:
CONSTRUCTION OF SEGMENTS
Submitted on: 25-06-2013
Submitted by:
MAHANKALI ROHITH
1011110133
SRM UNIVERSITY,
KATTANKULATHUR, TAMIL NADU.
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EXECUTIVE SUMMARY
On my assignment of the project in precast yard (chinthal). I am able to gain knowledge
about the construction procedure of the foundation in major constructions. This project is
being carried forward under the helpful belt of engineers and managers of the Larsen &
Toubro group. My internship covered a period of 15 days where I tried to gather practical
knowledge as much as possible. During my tenure segments work was going on, thus I got
opportunity to learn about segments. My report is based on the following sections:
A. Project Synopsis
B. Sequence of work
C. Quality Control and associated tests in Q.C. lab
D. Batching plant
E. Description of the site work
F. Planning
G. Safety Department
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A. PROJECT SYNOPSIS
The metro project is being carried out under the vigilance of the senior engineers and the
project manager who maintains the technical record of the on going project. The work goes
on 24 hours. The work in the site consists of 3 bays
Bay 1
Bay 2
Bay 3
The objective of this Construction Procedure is for efficient execution to cast segments at
casting yard and formulate as a summary of all quality related activities required to meet the
terms of the contract as per the approved drawings & relevant technical specifications.
B. SEQUENCE OF WORK
PIER HEAD SEGMENTS (end diaphragm):
Alignment of soffit and outer forms
Alignment of bulked head on both sides
Surveying on segments
Cutting ,bending and tying of reinforcement
Lifting and placing of rebar cage along with sheathing pipe
Alignment of HDPE sheathing pipe
Aligning and setting of internal shutter
Providing and fixing the inserts of lifting holes and drainage spouts
Final survey and rebar checking
Now laying and compacting is done
Then finishing of concreting is done
Curing process
Allow setting of concrete to gain 20 Mpa strength for removal of form work
De molding of external shutter and removal of internal shutter
Shifting of pier head segment from casting bed to stacking bed after gaining 25 Mpa
strength
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INTERMEDIATE SEGMENTS :
Alignment of soffit and Outer form
Alignment of bulkhead on one side
Shifting and alignment of match cast segment
Surveying is done
Application of formwork releasing agent/ deboning agent to shutter and match cast
face
Cutting, Bending & Tying of Reinforcement
Lifting and placing of rebar cage along with sheathing pipe.
Alignment of HDPE sheathing pipe.
Aligning & setting of internal shutter.
Providing and fixing inserts for drainage spouts, lifting holes, temporary pre-stressing
provisions, if required
Final survey and rebar checking
Laying, compacting & finishing of concrete
Curing
Allow setting of concrete to gain 20 MPa strength for removal of formwork
Loosening of external shutter and removal of internal shutter.
Lifting of match cast segment and shifting to stock yard after gaining 25MPa strength.
Alignment of temporary bulk head and the above said sequence shall continue till
completion of span
C. LABORATORY TESTS
C.1 TEST ON AGGREGATES:
Gradiation (Sieve) Analysis
Aggregate Impact value test
Flakiness index
Elongation index
Specific gravity
Water absorption
Moisture context
Bulk density
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C.2 TESTS OBSERVED ON SOIL:
Grain size (sieving) analysis
Liquid limit and plastic limit
Proctor density
Free shell index
C.B.R ( calfornia bearing ratio)
Chemical test on soil and water.
C.2.1 Cone Penetrometer:
Used to calculate Liquid Limit of the soil.
For non-plastic soil.
Deep penetration is made
No blows are provided.
Water content corresponds to 20 mm penetration.
C.3 TEST ON CONCRETE:
Slump Test
Slump test is done to determine the workability of concrete. This test is carried out
before doing concreting. Concrete is filled in the slump cone in 3 layers After
filling each layer it is compacted by a 16mm diameter tamping rod 25 times and
thus all 3 layers are filled up to the top of the cone. Then the cone is lifted up
gradually and the concrete is allowed to drop down. The slump is the drop in level
of concrete mass within the slump cone from top of the cone. For piling the slump
should be within the range of 150mm (minimum) to 200mm (maximum) as per
IS:456
Cube Test
Cube test is done for concrete to determine its compressive strength. The
concrete cube is made in a mould of 15 cm cube and tested in a machine called
compression testing machine Concrete cube is prepared and cured underwater
and tested after 28 days to determine final compressive strength.
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C.4 TEST ON CEMENT:
Fineness test
Standard conistation
Initial setting time
Final setting time
Soundness test
Compressive strength of mortor
CONCRETE INGREDIENTS PER CUBIC METER:
Ingredients of concrete source of supply M 40
(pier)
M 45
(segments)
Mix code CTM 135
(SC)
CTM272829
(SC)
OPC 53 grade (kg) Ultra Tech OPC 53 grade,
Malkhed
330 435
Flyash (kg) NTPC -ramagundam 90 85
Total cementitious (kg) OPC + Flyash 420 520
Coarse Aggregate- Fraction 1 (kg)-
20 mm (dry)
L&T Crusher- Sulthanpur 584 575
Coarse Aggregate- Fraction 1 (kg)-
10 mm (dry)
L&T Crusher- Sulthanpur 480 472
Fine Aggregate- Crushed stone
sand (kg) (dry)
L&T Crusher- Sulthanpur 713 702
Total water (kg) Chilled manjera /
Borewell water
185.5 163.9
Free water- cementitous ratio - 0.41 0.29
Cemical admixture(kg), Maximum
allowable dosage
BASF`s Glenium B233 2.60 4.16
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D. BATCHING PLANT
Located behind the quality control laboratory, the batching plant is for concreting and
concrete is produced.
With the progress of on-going layout of the segments ,parapet walls the structural design is
tested here and respectively the prototype is carried along the main site.
Relevant information about Batching plant operation.
Machine used CP 30;Schwing Statter, 30 cm(hour capacity)
Production capacity per cycle 0.5 m3
Capacity of a RMC truck 6 m3
Sand used(zone 2) Passed through 4mm sieve (or) <= 5mm
Stone chips used 20mm & 10mm
Concrete temperature <320C
Admixture Sikament(naphthalene based)
The following types of concrete used:
PIER M40
PIER CAP M50
SEGMENT M45
STATION PIER M60
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E. DESCRIPTION OF SITE WORK:
The metro project is being carried out under the vigilance of the senior engineers and the
project manager who maintains the technical record of the on-going project. The segments
are divided into
S1 - 1.7 m (pier head segment)
S2 - 3m
S3 - 3m
S4A - 3m
S4 - 3m
Segment width is of 8.8m
In S1- segment (1.7m) – 1m is of solid part and 0.7 m freely left part.
S1 -01 and S2-02 are pier head segments
Remaining all are intermediate segments
For 31m span , arrangements of segments is as follows :
S1-01 S2-02 S3-03 S4-04 S4-05 S4-06 S4-07 S4-08 S3-09 S2-10 S1-11
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KEY PLAN:
For 31 m span:
S1
S2
S3
S4
S4
S4-
A
S4
S4
S3
S2
S1
For 28 m span:
S1
S2
S3
S4
S4
S4-
A
S4
S3
S2
S1
For 25 m span:
S1
S2
S3
S4
S4-
A
S4
S3
S2
S1
For 22 m span:
S1
S2
S3
S4
S4-
A
S3
S2
S1
For 19 m span:
S1
S2
S3
S4-
A
S3
S2
S1
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A. Sequence of Casting for Pier Head Segments - Segment S1-01 / S1-11
1. Leveling the form work free / fixed end and support for bearing outstand
2. Closing the external form work of pier segment
3. Application of mould releasing agent
4. Cutting, Bending & Tying of Reinforcement
5. Lifting and placing of reinforcement cage
6. Fixing of guide cones on bulkhead
7. Fixing of first bulkhead in the pier side
8. Fixing of second bulk head in the match cast side
9. Profiling the sheathing pipe as per the co ordinates
10. Aligning & setting of internal shitters in position
11. Jacking and fixing up of internal form work
12. Installations of all inserts and lifting, temporary stressing arrangements etc.
13. Laying, compacting & finishing of concrete for segment
14. Allow setting of concrete for removal of formwork. Curing to be done during setting.
15. De-shuttering of internal form and bulkhead.
16. Shifting of pier head segment from Pierhead casting bed to stacking bed after gaining
25MPa
strength
17. Curing of segment for 14 days.
B. Sequence of Casting for Intermediate Segment (Long Line) - Straight span:
The pier head segment shall be cast first on independent bed and same shall be brought to
long
line bed to form the match cast segment for casting the adjacent segment. The sequence of
casting for intermediate segments in long line method is as follows
For typ. Segment S2-02 / S2-10
1. Aligning the soffit formwork for straight span
2. Lifting and positioning of S1 (Free and fixed) segment to match cast location for S2-02
and
S2-10 segment
3. Application of de-bonding agent at the match cast side
4. Close the external form work
5. Cleaning of shutter and application of mould releasing agent
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6. Placing of rubber cone in the match cast segment sheathing pipe for sealing of joint at
matchcast face.
7. Cutting Bending & Tying of Reinforcement
8. Lifting and placing of reinforcement cage
9. Placing and fixing of bulk head
10. Installation and profiling of sheathing pipe as per the co-ordinates.
11. Placing of internal form work.
12. Installation of all inserts for lifting, temporary stressing arrangements.
13. Final survey.
14. Casting of segments (S2-02).
15. Allow setting of concrete. Curing to be done during setting.
16. De-shuttering after the requisite strength, external and internal form work with bulkhead.
17. Curing of segment for 14 days.
18. Internal shutter move from S2-02 to S2-10 and with above sequence casting of S2-10 to
be
carried out.
For typ. segment S3-03 /S3-09
1. Shifting of internal shutters on S3-03 and cast against S2-02 and end stopper.
2. Placing of bulkhead and alignment.
3. Placing of rubber cone in the match cast segment sheathing pipe for sealing of joint at
matchcast face.
4. Cutting Bending & Tying of Reinforcement
5. Lifting & placing of rebar cage.
6. Installation and profiling of sheathing pipe as per the co-ordinates.
7. Placing of internal form work.
8. Installation of all inserts for lifting, temporary stressing arrangements.
9. Final survey.
10. Casting of segments (S3-03)
11. Allow setting time of concrete. Curing to be done during setting.
12. De-shuttering after the requisite strength (external and internal formwork with bulkhead).
13. Curing of segment for 14 days.
14. Same sequence follows as parallel activity forecasting for casting S3-09 also.
For typ. Segment S4-04 / S4-08, S4-05/S4-07
Casting of above said segments shall be followed as sequence mentioned for segments S3/S9
For typ. segment S4-06
After completing S4-07 internal shutters shall move from S4-07 to S4-06 and concreting of
S4-06
shall be carried out with above sequence
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C. Sequence of Casting for Intermediate Segment (Long Line) - Curved span:
For curved span also pier head segment casted on Pierhead Mould and same shall be brought
to
long line mould to form the match cast segment for casting the adjacent segment, the
sequence of
casting for intermediate segments in long line bed as follows:
For typ. Segment S2-02 / S2-10
1. Aligning of soffit formwork for curve span of required radius of curvature.
2. Shifting of S1-01 /S1-11 segments to match cast location for casting S2-02/S2-10.
3. Aligning of temporary bulk head.
4. Applying of de-bonding agent over match cast segment.
5. Cutting, Bending & Tying of Reinforcement
6. Closing of external form work.
7. Placing of rubber cone in the match cast segment sheathing pipe for sealing of joint at
matchcast face.
8. Lowering of rebar cage.
9. Installation of sheathing pipe.
10. Profiling of sheathing pipe as per co–ordinates.
11. Moving of internal form work.
12. Jacking of internal form work.
13. Installation of all inserts for lifting/temporary stressing arrangements.
14. Final survey.
15. Casting of segment (S2-02).
16. Allow setting of the concrete. Curing to be done during setting.
17. De-shuttering of internal form work after requisite strength.
18. Curing of segment for 14 days.
19. Internal form work shall move from S2-02 to S2-10 and casting of S2-10 shall be carried
out
with respect to above sequence.
For typ. segments S3-03 / S3-09
1. Shifting of internal shutter on S3-03 and cast against S2-02 and end stopper.
2. Placing of bulk head and alignment.
3. Placing of rubber cone in the match cast segment sheathing pipe for sealing of joint at
matchcast face.
4. Cutting, Bending & Tying of Reinforcement
5. Lowering of rebar cage.
6. Installation and profiling of sheathing pipe as per co-ordinates
7. Placing of internal form work& alignment
8. Installation of all inserts for lifting, temporary stressing arrangements.
9. Final survey.
10. Casting of segments (S3-03).
11. Allow setting time of concrete. Curing to be done during setting.
12. De-shuttering after requisite strength (internal form& bulk head).
13. Curing of segment for 14 days.
14. Same sequence follows as parallel activity for casting S3-09 also.
For typ. segments S4-04 / S4-08, S4-05/S4-07
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Casting of above said segments shall be followed as sequence mentioned for segments S3/S9
For typ. segments S4-06
After completing S4-07 internal shutters shall move from S4-07 to S4-06 and concreting of
S4-06
shall be carried out with above sequence
F. PLANNING
Planning department is the nucleus of the project work. The planning department works
mainly in two phases:
PROJECT MANAGEMENT
CONTROL SYSTEM
PROJECT MANAGEMENT:
This system is mainly governed by the contract system. It also consists of two parts:
1. Financial part: - this wing mainly focuses on the optimum utilization of the budget
limit provided in the tender.
2. Technical part: - this wing looks after the procedure and progress of the project and
the quantity and quality of the materials required keeping in mind the financial
restriction.
The GCC (general condition of contract) is included here.
This management also looks after the schedule of the project i.e. how the project will work
keeping in mind the time factor. In every project operated by L&T there are 10 schedules
mostly (S0-S10) and some of the schedule are as follows:
Invoicing schedule
Plant and machinery schedule
Staff schedule
Materials schedule
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CONTROL SYSTEM:
The main principle governing the control system is the reconciliation i.e. suppose a particular
work moves out of the prescribed schedule then how it can be adjusted with the remaining
schedule so that the project totally completes in the prescribed tenure.
Now in order to reconcile or to have a close watch on the work monitoring system is
followed and it is of 4 types:
Daily progress report(DPR)
Weekly progress report(WPR)
Monthly progress report(MPR)
Final completion report
TERMINOLOGIES:
1. ROTE(return on talent employed): reports the utilization of optimum limit of the
skilled man force on the project site along with the rate of work progress. It also
checks the efficiency of the workers in different field and schedule them accordingly
to the project progress.
2. ROCE(return on capital employed): reports the efficient utilization of the capital
according to the pre-planned schedule of the project progress and reports for plus or
minus of the force limit as per progress.
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G. SAFETY AT CONSTRUCTION SITE
All Safety measures are taken to ensure basic discipline in a construction site as a compulsory
act. A number of safety measures for on-site construction workers were laid in site safety
plan.
With workers at site of this project, Safety Management was in place. They care for an
individual life. To ensure this safety a board of safety council have been vocationally trained
and alerted on site. They have several sections.
These include:
Incorporation of a Safety Policy as a commitment by the top management.
Formulation and documentation of various procedures for safety.
Development of a detailed Health, Safety and Environment (HSE) manual to be
followed at all construction sites, including mishap reporting and investigation.
Sharing of best practices with external agencies such as British Council, Loss
Prevention Association of India, National Safety Council, consultants and other
government agencies.
In-house training and education at construction sites and at head office.
Safety organisation with qualified Safety Professionals who help various Business
Units in improving safety conditions at construction sites.
At L&T, safety is integrated into all work practices. Based on their extensive experience, they
have also developed safety manuals, training and education programmes that form a
comprehensive Environmental and Safety management system, applicable to all their
projects. Every L&T subcontractors and business partners are asked to adopt their Safety
Policy.
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EPILOGUE
With effective observation we come to the conclusion of an overall knowledge gain about the
metro rail segments.
Although complete structural details could not be gained due to short span of time but an
overview of the foundation construction was all we could gather.
RECOMMENDATIONS/REFLECTIONS:
- The management of the works that are being carried out is appreciable.
- Bare electric cables are there on the site which might be really dangerous and cause
accidents
The report would not be completed without adequate provision of data by the following
persons:
- Soman (ass. Project manager)
- Sachin (sr.eng)
- Krishnam raju (sr.eng)
- Santhosh (eng)
- Santhosh .v
- Laxman rao
- Gopal Krishna
- Vamshi
I thoroughly enjoyed the company of the seniors and also all the staff members. All the staffs
are helpful and their eagerness proves the healthy environment among the company staffs.
Overall i enjoyed a comfortable stay, healthy company, and quality knowledge and enjoyable
experience here.
Sincere thanks to Larsen and Toubro.