BSCPL Infrastructure Pvt. Ltd is constructing a four-lane bridge over the Mahanadi River in Chhattisgarh, India as part of a contract to reconstruct 250 km of National Highway 53. The segmental bridge is being built using the lanuching girder method, where precast concrete segments are placed using a launching girder and temporary supports. Segments are dry fitted, glued with epoxy, post-tensioned with 7-ply cable strands using hydraulic jacks, then grouted to form each span. Precast segments are lifted into place by the launching girder's gantry and secured to sliding supports. The launching girder is then advanced to the next pier to begin constructing

1. BSCPL Infrastructure Pvt. Ltd
@ CONSTRUCTION OF BRIDGE IN NH-53,
In Arang to Saripali Road, (C.G.)
An In-plant Training Report
Submitted by
SUKHDEEP SINGH JAT
U12CE117
In partial fulfillment for the award of the degree of
BACHELOR OF TECHNOLOGY
IN
CIVIL ENGINEERING

2. BSCPL Infrastructure Ltd is an ISO 9001: 2000 accredited infrastructure
development company. Which pioneers in execution of Road Projects, Irrigation projects
and recently diversified in Real estate and Hydro Power plants. Started as B Seenaiah and
Co, a partnership firm in 1982. Later it converted into a Public Company in 1998 as B.
Seenaiah and Company (Projects) Ltd and it was again renamed as BSCPL Infrastructure
Ltd in 2008.
ABOUT THE COMPANY

3. ABOUT THE PROJECT
This superstructure falls in between the NH-53 connecting states of Gujarat,
Maharashtra, Chhattisgarh and Orissa. This Bridge is being built on the Mahanadi River near
Arang. The company holds the contract of developing and reconstruction of NH-53 of about 250
km in length starting from Arang to Saraipaali (Basna) near Orissa border. This highway is
undergoing numerous construction of bridges, flyovers, canals etc,.
This road laid on the bridge has to be of four lane road intensifying the traffic to its
maximum. This road connects the Rajim (District) to the developed cities leading to immense
means of transport. The major objectives of the project is :-
(i) to cover for the damaged bridge shortening the distance between to major cities
for Rajim.
(ii) to broaden the road for the transportation purpose.
(iii) to repair the damaged roads minimizing the road accidents.

4. Figure 1.1. Index Map Showing the Road (Arang to Sariapali)

5. DESCRIPTION ABOUT SUPERSTRUCTURE
The type of bridge that is being constructed over Mahanadi in Chhattisgarh is known as
Segmental Bridge. A Segmental Bridge is type of bridge built in short sections (called
segments).ie., one piece at a time. The bridge is made of concrete that is either cast-in-place
(constructed fully in its final location) or precast concrete structures ( built at another place and
then transported to their final location for placement in the superstructure).
Figure 2. A Picture Representing Ongoing Construction

6. DATA NEEDED FOR DESIGNING A BRIDGE
Geographical Details
• A plan of the site showing all the obstacles to be bridged such as
rivers, streets, roads or railroads, the contour lines of valleys etc.
• Required width of the bridge, width of the lanes, walkways, safety
rails, crash barriers etc.( this bridge is designed as four lane of the
national highway).
• Soil conditions for foundations, results of boring with a report on the
ground and the soil mechanics data.

7. Site Details
Here the site exploration is done by Boring. The site when explored provided the data
are as follows :-
(I) Depth, extent, and composition of critical soil strata,
(II) Ground water level and its fluctuation
(III) Depth of bed rock(when necessary),
(IV) Estimate of engineering properties of soil,
(V) Initial selection of foundation possibilities,
(VI) Subsurface property of the area,
(VII) Evaluation of settlement characteristics of various soil layers,
(VIII) Evaluation of bearing capacity of the soil.

8. Figure 3. Above Diagram representing results of Boring

9. MATERIALS USED IN STRESSING
1) Bearing Plate
All the cables passing
through the ducts are
held together in the plate
with holes. The cables are
stressed after clinging the
live wedge into the holes
of the plate so that the
cables holds up to the
stressing
Figure 4. Plate through which pipes are strands are coming
out

10. 2) Live Wedge
It’s a circular clamp
for hooking up the
cable strand to the
bearing plate. It holds
the most major part in
stressing. The live
wedge actually holds
to the another side
with the plate with the
cables in it while
stressing and clings to
the other side so that
the cables should
remain stressed.
Figure 5. Live Wedge

11. 3) Collar Plate
It’s a cap to the
bearing plate. After
the stressing is done
the strand is left up to
an extent and then the
bearing plate is
covered with the
collar plate fitting it
with the screw.
Figure 6. Cap of the Bearing Plates

12. 4) 7 ply pipe strand
This cable is referred
as the 7 ply pipe
strand its because of
the seven cables of
diameter 2mm are
strangled in one in a
helical manner and
the whole diameter of
the cable strand is
7mm. Each strand
passing through the
ducts holds the
capacity of holding
80 tons of load
Figure 7. Cable strand

13. 4) Resin and Hardener
This chemicals are
mixed in the ration of
1:2 (Resin:Hardener )
and applied at the
front and back surface
of the segment after
dry matching.
Figure 8. Chemical used for Gluing
Resin Hardener

14. MACHINES USED IN CONSTRUCTION
Figure 9. Launching Girder
Work :- The picture showing
above is of Launching Girder
which is used for the segment
feeding and laying out the span
in a Segmental Bridge
construction. The top portion of
the Launching Girder is known
as gantry which is used to lift the
supports and drag to the point
where it has to be fixed next. The segments were supposed to be hold up by the clamp attached
with the sliders and were moved towards the direction of the next span being build and aligned.
1. LAUNCHING GIRDER

15. Figure 10. Multi Strand Hydraulic Stressing Jack
These hydraulic jacks are used to stress the cable strands passed through the ducts to make
the whole span into one. The strands were clamped with the live wedges on one side and
were stressed using the stressing jacks leaving the 5% of slip in length from the rear
portion considering the strands have been stressed properly.
2. Hydraulic Stressing Jack

16. A BRIEF EXPLANATION OF LAYING OUT ONE SPAN
1. The machine shown in the above provided picture is known as Launching Girder.
2. It stands on the pier of the bridge with the supports placed at the piers .i.e., front, middle and
rear support.
3. Front support is provided at edge of the span from where the next span has to be started and
the second support is provided at the second last pier from the where the next span to be made
while the rear support is provided for stabilizing the girder
4. The entire weight of the launching girder is hold on the hydraulic jack.
Figure 11. Construction Of Bridge on Mahanadi River

17. Figure 12. Hydraulic Jack
5. This hydraulic jack has the capacity of holding up to 500 ton of the load by itself.
6. Then the next step comes .i.e., Auto launching. It refers to the moving of the entire
launching girder to the next pier. The middle support was held by the gantry and it's
sliding through the structure moving for the next support.

18. Here are some of the photos showing the auto launching process:-
Figure 13 (a) Figure 13 (b)
Figure 13 (c)

19. 7. Level checking and support fixing:- While the erecting of the segment middle support and
front support should be at the same level. Middle support on temporary tower. The levelling
for the middle and front support is done using Dumpy Level.
Figure 14. Pre-Casted Structure
8. When the auto launching is
done and support for the
girder is settled than the
segment feeding is done
,.i.e., the segment is lifted
by the gantry and then it is
transferred to the slider
which holds up the pre-cast
concrete structures as a
temporary.

20. 9. Dry matching:- It is the alignment of the segment in their places.
10. Gluing:- pasting of two segments with the calculated load with the mixture of hardener
and the resin with the ration of 1:2.
11. When the structures are held by the sliders and the segments are joined then the strands
of 7 ply pipe( used in this bridge as prescribed in the drawings) is inserted through the
ducts joining all the segments.(one strand can approx. carry the load of 20 ton). This
process is known as "Threading".

21. This is how it looks after threading all the clamps holding the segments are held by the
sliders and the structure is balanced and the total load is transferred to the jacks.
12. Stressing is done once the span is been held temporary making the span still after the
removal of clamps holding the bridge.
13. When once the stressing is done then we move on to the "Grouting", which means applying
the cement and cebexes mixture with water with the applied air pressure into the ducts.
Figure 15 Clamps holding the segment

22. 14. Grouting is done to prevent the corrosion that may occur in the stressing pipe and maintains
its property for a long period.
15. But before grouting it has to be made sure if the ducts have any leakage holes or not because
if there will be a leakage then the mixture applied throughout the duct may not be settled
properly. Thus, it is checked by applying the limewater though the duct within a applied
water pressure.
16. After grouting the two span is joint with the expansion joint and after putting the expansion
joint cast-in-situ is done.

23. REFERENCES
1. Soil Mechanics and Foundation by Dr. B.C. Punmia.
2. Structural Analysis by S.S. Bhavikatti.
3. Jr. Engineer Sourabh Sinha at BSCPL Infrastructure Pvt. Ltd.
4. Wikipedia