This document is a submission by Sourav Goswami describing his 7-day internship project focused on the construction of a metro rail bridge. The project was conducted under Rail Vikas Nigam Limited and Gammon India Limited. Sourav thanks the project guides and staff who provided guidance and knowledge about bridge construction activities including piling, pile caps, piers, bearings and segments.

1. SUBMITTED BY :- PROJECT GUIDE :-
SOURAV GOSWAMI Mr. S.C MITRA
MVJ COLLEGE OF ENGINEERING, BANGALORE MANAGER –(PROJECT)
(02.01.2016 to 09.01.2016) RVNL - KOLKATA

2. ACKNOWLEDGEMENT
I would like to express my special thanks of gratitude to
Mr. Amit Kumar Roy (CPM/LINE, RVNL Kolkata),
Mr. Avijit Roy (GM/P, RVNL KOLKATA),
Mr. S.C.Mitra (MANAGER, PROJECT, RVNL KOLKATA), Staffs and
Supervisors of RVNL and GAMMON INDIA LIMITED who gave me
the golden opportunity to do this wonderful project on the topic
CONSTRUCTION OF METRO RAIL BRIDGE, which also helped me in
doing a lot of Research and I came to know about so many new things. I
am really thankful to them.
Lastly, I would also like to thank my parents who helped me a lot in
finalizing this project within the limited time frame.
SOURAV GOSWAMI
(PROJECT INTERN)

3. SUMMARY
The following project focuses on the viaduct and its various parts, describing
their individual characteristics as well as the methods being used for its
construction. The project was done in a brief span of seven days. The topics
discussed here were the subjects of my inspection. The Project was done as
summer internship under Rail Vikas Nigam Limited (RVNL), in association
with Gammon India Limited.
This internship has helped me gather practical knowledge of the onsite
activities that takes place while constructing a viaduct/bridge.
SOURAV GOSWAMI
( PROJECT INTERN )

4. CONTENT
1. BRIDGE
2. PILE
3. PILING ACTIVITY
4. PILE CAP
5. PIER
6. PIER CAP
7. BEARING
8. SEGMENT
9. SEISMIC RESTRAINER
10. CASH BARRIER

5. BRIDGE
A bridge is a structure built to span physical obstacles without closing the way
underneath such as a body of water, valley, or road, for the purpose of providing
passage over the obstacle. There are many different designs that all serve unique
purposes and apply to different situations. Designs of bridges vary depending on the
function of the bridge, the nature of the terrain where the bridge is constructed and
anchored, the material used to make it, and the funds available to build it. During
the design process, every bridge can be divided broadly into three parts:
-Superstructure.
-Substructure.
-Foundation.
MAJOR PARTS OF A BRIDGE
The major parts of a bridge are as follows:
- Pile.
- Pile Cap.
- Pier.
- Pier Cap.
- Bearing.
- Segment.
- Seismic Restrainer.
- Crash Barrier.

6. PILE
 There are three types of pile foundations according to their construction methods:
1.Driven piles, 2.Cast-in-situ piles, and 3.Driven and cast-in-situ piles.
 Pile foundation selection depends on the soil data received from soil exploration
bore holes at different depths.
 Selection of pile foundation types and length depends on following conditions:
-Soil conditions
-Loads from structures
-Nature of loads
-Number of piles to be used
-Cost of construction
 There are three types of pile foundation based on load transfer mechanism:
-End bearing piles
-Friction bearing piles
-Combination of end bearing and friction bearing piles.
 The purpose of pile foundations is:
– To transmit the buildings loads to the foundations and the ground soil layers
whether these loads vertical or inclined
– To install loose cohesion less soil through displacement and vibration.
– To control the settlements; which can be accompanied by surface foundations.
– To increase the factor of safety for heavy loads buildings.

7. PILING ACTIVITY
 SITE CLEARING AND PLACING BARRICADING.
 SURVEYING WORK.
 CASING AND DRIVING.
 BORING.
 CHECKING FOR FOUNDING LEVEL.
 MAKING AND LOWERING OF REINFORCEMENT CAGE.
 LOWERING OF TREMMIE PIPE.
 FLUSHING.
 CONCRETING.

8. PILE CAP
 A pile cap is a thick concrete mat that rests on concrete or timber piles that have
been driven into soft or unstable ground to provide a suitable stable foundation. It
usually forms part of the foundation of a building, typically a multi-story building,
structure or support base for heavy equipment. The cast concrete pile cap
distributes the load of the building into the piles. A similar structure to a pile cap is
a "raft", which is a concrete foundation floor resting directly onto soft soil which
may be liable to subsidence.
 The mat is made of concrete which is an aggregate of small rocks and cement. This
mixture has to be supported by a framework to avoid sagging and fracture whilst
setting. This process is known as shuttering and reinforcing. The materials used are
long twisted steel bars between the piles held in shape by thinner tie wires. Once
this steel mat is laid, timber is attached around the perimeter to contain the wet
concrete mixture. Once poured, (usually as a series of small loads), the concrete is
stirred to remove any air pockets that might weaken the structure when set. The
concrete undergoes a chemical change as it hardens and this produces a lot of heat.
Sometimes, if the mass of concrete is very large, pipes
carrying refrigerant coolant are used in the mass to assist the setting process to
prevent the concrete from cracking.

9. PIER
 A pier is a raised structure typically supported by well-
spaced piles or pillars. Bridges, buildings, and walkways may all be
supported by piers. Their open structure allows tides and currents to
flow relatively unhindered, whereas the more solid foundations of
a quay or the closely spaced piles of a wharf can act as a breakwater,
and are consequently more liable to silting. Piers can range in size and
complexity from a simple lightweight wooden structure to major
structures extended over 1600 meters.

10. PIER CAP
The upper or bearing part of a bridge pier, usually
made of concrete or hard stone.
It is designed to distribute concentrated loads evenly
over the area of the pier.

11. BEARING
 A bridge bearing is a component of a bridge which typically provides a resting
surface between bridge piers and the bridge deck. The purpose of a bearing is
to allow controlled movement and thereby reduce the stresses involved.
Movement could be thermal expansion or contraction, or movement from
other sources such as seismic activity. There are several different types of bridge
bearings which are used depending on a number of different factors including
the bridge span. The oldest form of bridge bearing is simply two plates resting
on top of each other. A common form of modern bridge bearing is
the elastomeric bridge bearing. Another type of bridge bearing is the
mechanical bridge bearing. There are several types of mechanical bridge
bearing, such as the pinned bearing, which in turn includes specific types such
as the rocker bearing, and the roller bearing. Another type of mechanical
bearing is the fixed bearing, which allows rotation, but not other forms of
movement.
 The purpose of a bridge bearing is to support the superstructure at a constant
elevation, to carry all forces from the superstructure into the substructure and
to allow necessary superstructure motions to take place. Forces to be applied to
bridge bearings can come from any of the loads associated with the bridges.

12. SEGMENT
 A segment is a bridge built in short sections (called segments), i.e., one piece at a
time, as opposed to traditional methods that build a bridge in very large sections.
The bridge is made of concrete that is either cast-in-place (constructed fully in its
final location) or precast concrete (built at another location and then transported to
their final location for placement in the full structure).
 These bridges are very economical for a span of 28m or so.
 For example, the span of 28m is divided into segments (FS1, FS2, FS3, FS4, FS5,
RS1,RS2,RS3,RS4,RS5) where the first and last segments are of 2m and the rest are of
3m.
 In cast-in-place bridges, the falsework is connected to the previously installed
concrete and allowed to cantilever freely. Next, the permanent reinforcing steel and
supports are installed. Finally, the concrete is placed and cured, freeing the
falsework to be moved.
 In pre-cast bridges, the concrete segment is constructed on the ground, and then
transported and hoisted into place. As the new segment is suspended in place by
the crane, workers install steel reinforcing that attaches the new segment to
preceding segments. Each segment of the bridge designed to accept connections
from both preceding and succeeding segments.

13. SEISMIC RESTRAINER
 Most bridges have movement joints to accommodate thermal
expansion an contraction without inducing large forces in the bridge.
During an earthquake, the joints pose a hazard. If the relative
displacement of adjacent frames or girders exceeds the available seat
width, the span will collapse.
 The seismic restrainer is provided at the bridge construction to prevent
or minimize the relative displacement caused due to the seismic waves
induced by earthquake or tsunami.

14. CRASH BARRIER
 A wall is cast around the pier around the road level, which
is known as Crash Barrier.
 The gap of 25mm is maintained between pier and crash
barrier.
 Crash Barriers are generally provided to protect the pier
from damages by the road accidents caused by the vehicles
when it gets crashed with the pier.

15. THANK
YOU