Conceptual Design Of Chenab Bridge- Indian Railways
The Chenab Bridge is a steel railway arch bridge with a total length of 1315 metres. It is formed by an approach bridge, which is 530 metres long, and an arch bridge, which is 785 metres long. A 467-metre-long steel arch (one of the longest in the world) supports the steel deck. The deck, which is 13,5 meters wide and has two tracks running on it, is located about 320 metres above the surface of the river flowing in the valley. WSP Finland has the main responsibility for the planning of the bridge. The design of the steel arch is done by subconsultant Leonhardt, Andrä und Partner of Germany.
Design basis notes for the Chenab Bridge
Fig. 3. View of the Chenab Bridge design model.
The bridge Owner set strict rules and standards that had to be obeyed in the design. Indian Railway
Standards (IRS Standards) had to be used wherever applicable. British Standards, UIC Standards and other
international standards including Eurocodes could be used as a supplement.
The design speed of the railway was set to be 100 km/h and the design life had to be 120 years. Fatigue
assessment shall be done as per BS: 5400 Part –10.
Wind loads will be derived using physical topographic models of the site and tests in a wind tunnel
laboratory. Even full-scale models are required. The test results of the bridge are used to extract equivalent
static wind loads, which are used in the final structural analysis. These equivalent static wind loads take into
account wind-induced dynamic actions of the bridge, as well as size reduction effects related to the patchy
distribution of wind pressure peaks. The service wind load corresponds to a maximum wind pressure of 1500
Pa. The wind load is governing the arch design.
In addition to all conventional railway bridge loads, this bridge has to sustain special blast loads specified by
the Client, and to provide sufficient redundancy in case of local failure. The most important design criteria in
the steel deck is fatigue.
