3. INTRODUCTION
• Indian railway has undertaken the mega-project of construction of new railway line in the
state of Jammu and Kashmir, from Udhampur to Baramula .
• The project has been declared as a national project.
• The alignment crosses a deep gorge of the Chenab River.
• In the design work the National codes of India, Indian Railway Standards (IRS), Indian road
congress (IRC) recommendations and Indian standards (IS) have been supplemented with
international standards like British standards (BS), standards of the International union of
railways (UIC) and some national codes.
• Location of the Chenab bridge in Reasi district of Jammu and Kashmir in India, about 600 km
north of New Delhi, (Google map- 2012 )
4. CHENAB BRIDGE PROJECT PARTIES
Clint : Konkan Railways Corporation
Main contractor : Chenab Bridge Project Undertaking
Principal designer : WSP Finland
Structural designer : WSP Finland & Leonhardt, Andra und
Partner
Third-party inspector :Flint & Neil
5. • The indian railways purposed a railway line between katra ( district of Kashmir) and Qazigund
(district of jammu). Which crosses the river Chenab. Therefore, it was proposed to build a bridge
on this route, Known as the Chenab bridge. This railway link will connect Kashmir and jammu
within a travel time of 6 hours and 30 minutes.
6. Features of Chenab Bridge
Chenab bridge will be the highest Railway Bridge in the world being 359 m above the river bed level. The Chenab Bridge
will be 35 meters higher than the iconic Eiffel Tower in Paris ( France).
More than 1300 workers and 300 engineers have been working round the clock to complete the bridge.
The construction of the bridge involved the fabrication of 28,660 MT steel,10 Lakh cum Earthwork,66,000 cum concrete
and 26 km Motorable roads.
The arch of the bridge consists of steel boxes. The overall weight of the arch is 10,619 MT.
The Chenab bridge is designed to withstand high wind speed up to 266 km/hour.
The Chenab Bridge will remain operational at a restricted speed of 30 Km/hour.
As per the Centre , the Chenab bridge is being built ₹ 1,486 Crore.
The Design life of the bridge is at least 120 years.
Approximately 584 Km of welding was done to join the different parts of the structure, Which is to the tune of the
distance between Jammu Tawi to New Delhi.
7. Most sophisticated “ Tekla” (3D BIM software for modeling building structures.) Software used for structural
detailing of the arch.
Structural steel suitable for -10°C to 40 °C temperature
Design speed : 100 kmph
Blast resistant design in consultation with DRDO (Defence Research & Development Organisation).
Designed to bear earthquake force of high intensity Zone-V
Phased array ultrasonic testing machine used for testing of welding.
8. Components of Chenab bridge
• The Chenab bridge consists of a single arch of 467 m over the Chenab river and will have
two railway lines. Its deck will be continuous over the supports with expansion joints at
S10,S70 and S180 supports.
• The proposed railway bridge consists of 18 piers resting on the ground. Out of which 4
piers are resting on the left abutment and the remining 14 piers on the right abtment.
• The width of the river at the bed level (RL 492 m) is about 150 m.
• The rail track on the bridge will be at RL 854.517 m.
10. Geology Of Site
The Himalayas are full of geological surprise with faults, folds, shear zones etc. present due to ongoing tectonic
activities in the region. The geology at the site of Chenab Bridge are:
The site comprises of shiwaliks and pre tertiary rocks.
The main sub-type of rocks comprises of dolomite and limestone.
Some of the pier locations comprise quartzite and shale rocks.
There are no significant shear zones or cavities in both the abutments.
Top layes of the rocks at abutments are highly fractured and represent a block mass. However, the bottom layers of
rocks are stable and strong enough for a good foundation.
Both abutments have foliation joints with two sets of sub-vertical joints.
The joints are irregular and very rough, with no or little infilling
The spacing between the foliation joints is extremely less.
The rock mass is dry and highly interloked.
11. Rock Mass and Rock Joints Properties
Perliminary analysis of rock mass can be carried out by finding various rock mass indexes.Such indexes
characterize the rock mass into four categories, i.e: Good, Fair, Poor and very poor rock. The characterization of
the site rock mass by various indexes is listed :
1. Rock quality designation (RQD) : 49 (Fair- Poor)
2. Rock mass rating (RMR) : 48 (Fair)
3. Q-Index : 6.13(Fair)
4. Geological strength index (GSI) : 43 (Fair)
Several in-situ and laboratory tests were carried out for establishing the rock mass strength and deformation
properties. The geotechnical properties of the left and right bank abutments of the Chenab Bridge are :
Density 2.762 gm/cc
Specific Gravity 2.81
Porosity 1.30 %
Unconfined compressive strength
(UCS-dry)
160.50 MPa
12. Point load index 14.12 MPa
Sonic wave velocity 4.60 km/sec
Modulus of velocity 4.41x104 MPa
Poisson’s ratio 0.22
Cohesion 22.50 MPa
Friction angle 58°
Rock-mass properties Rock-joints properties
Cohesion (C) 1.40 MPa Cohesion (C) 0.80 Mpa
Friction angle 44.42° Friction angle 38°
Bulk modulus 5x1010 Pa Normal stiffness 4x1011 Pa/m
Shear Modulus 3.8x1010 Pa Shear stiffness 3x109 Pa/m
13. Foundation and Slope Design
• The groundwater table is located far away from the base of the foundation. However, Short-term rainwater might
develop some hydrostatic pressure. Therefore, the impact of hydrostatic pressure was considered in the
foundation analysis.
• Other than the usual load combination, a higher load factor was considered for seismic forces in the foundation
analysis because of the presence of the bridge in the seismic zone-V
• For foundation stability, 2-3 m deep trial pits were excavated for all the foundations from S-10 to S-70for
geological logging and conducting plate load tests.
• Also, for more stability of foundation at S-40 and S-5, drifts were excavated about 8-10 m below the foundation
level as foundation S-40 and S-50 location are the most critical arch foundations. All the weight of the arc will be
supported by the foundation located at these locations.
14. • Isolated footing and concrete pedestal were constructed for each support on both sides of the abutments. Steel
piers were bolted using a base plate above the concrete pedestal of each foundation.
• Structural steel piers were used for the foundation construction of the 18 piers.
• A wedge failure analysis was carried out at both left and right abutments. For this purpose, DIPS and SWEDGE
software were used.
• A preliminary analysis indicated the wedge failure at the downstream side of both left and right abutments. Thus,
the risk of wedge failure was avoided by flattening the slopes from 70° horizontal to 63°.
15.
16. Slope Stabilization Measures
All the 18 piers were constructed on the slop. Piers provide
the base for deck construction, and all the piers of Chenab
bridge are located on the slope. Therefor, to improve the
overall stability of the slope, the following measures were
taken for slope stabilization
After excavating the slops, a 100mm thick steel fiber-
reinforced shotcrete was applied in two layers 50mm
each to provide instant stability.
Further, a minimum of three to five rows of passive bolts
of 32mm size and 11m length were setup in 100mm size
boreholes perpendicular to the slope. Rock bolts were
provided at 2.5m spacing.
Also, pre-stressed bar anchors of 625 KN capability and
33m length were installed in 5 rows at S-60 pier location.
Pre-stressed cable anchors of 980 KN capacity and 40m
length were installed in 5 rows at S-50 pier location.
17. For ensuring long life of the rock bolts and
rock anchors up to 120 years, the following
measures were undertaken:
A corrosion inhibitor solution was applied
to the rock bolts.
Further, a minimum grout cover of 25 mm
was provided between the rock and the
bolts.
The stratum surrounding the pre-stressed
rock anchors was grouted to reduce water
ingress through the surrounding material.
Then the pre-stressed rock anchors were
provided with double corrosion protection
sheets.
18. Construction methodology and
sequence
No electricity available near the site, and the water available in
near by channels was not suitable for concrete production.
Therefore, electricity was produced at the site, and provisions were
made for supplying river water from far away mountains.
Firstly, the foundation and slope stabilization works were started. A
total of 18 pier were constructed.
A cable crane will be used in the main span for the bridge erection.
After construction, the cable crane will be kept at the site to be
used for repair and maintenance works in the future.
The bridge consists of 25.000 tons of steel structures. Steel columns
of 100 m length will be constructed with the help of a cable crane with
a capacity to handle a maximum weight of 34 tons.
19. Construction Sequence of Arch The erection process of the deck and arch will be proceeding
simultaneously. Both the arch and the deck will be maintained up
to a maximum cantilever length of 48 m.
When the next arch pier support would be reached, temporary
cables will be set up to support the constructed arch. After that,
the new arch pier will be constructed using the cable cranes on
the free end.
The process will be continued until the last pier of the arch is
constructed.
The final segment of the arch will be constructed using a cable
crane. Two halves of the arch will be adjusted using hydraulic
jacks before the final connection.
Finally, the temporary cables will be removed, and the final
connections will be made.
The erection of the arch will be
done using derrick crane and
cable crane.
The process has begun will the
erection of the main piers by
cable crane. After that, the deck
is lunched up the axes of
support S-40and S-50
The derrick crane will be placed
on top deck. The maximum
lifting capacity of the derrick
crane is 100 tons.
20. A derrick crane is a lifting device usually composed
of mast (frame or tower) and lifting arm.
There are three or four lines connecting the mast
to the lifting arm, which controls it goes up and
down.
Crane cables is a term used to cover a range of
specialist cables powering and controlling
cranes. Used across heavy industry including
mining and marine
22. The highest railway bridge
in the world:
Upon completion, the Chenab
bridge will be the highest
railway bridge in the world.
Currently, Najiehe railway
bridge located in china is the
highest railway bridge in the
world with a height of 310 m.
23. Project Status:
Aug 2019: 80% of construction work has been
completed on the bridge, and is expected to be
opened in mid 2020
Nov 2019: 83% work has been completed on the
bridge, and is now expected to be opened in
march 2021.
Jan 2020: it is now expected to be opened in
December 2021.
Apr 2021: work on both the ends of the bridge’s
arch is finally completed. It is now expected to be
opened in 2022.
Jun 2022: about 90 % of construction work has
been completed, and is now confirmed to make
the bridge operational by December 2022.
24. • Aug 2022: The bridge’s remaining work on
the final joint was completed, and was
inaugurated on 13 August 2022.
• Feb 2023: Track laying on the bridge starts.
• Mar 2023: The track laying is completed
and a trial run has been conducted on it.
The bridge, along with the entire route from
Jammu to Baramulla, is expected to
become operational by December 2023 or
by January/February 2024.
