Chenab Bridge: Connecting the Arch Up in the Clouds

Facts

• The Chenab Bridge is the highest steel arch bridge for railway traffic in the world, 359 metres above the river bed; the length of the arch is 467 metres; the total length of the bridge is 1,315 metres
• Designed for heavy wind loads and earthquake zone V as per the relevant IS Codes 
• All steel structures are modelled by 3D TEKLA software, which ensures compatibility of members during erection; the total amount of steel is 27,000 tons
• Erection of the arch was done by suspension cable crane
• The bridge has been designed for blast load
• Critical members are designed for adequate redundancy and operation at the lower level of efficiency

Client: Konkan Railway Corporation Limited (KRCL) on behalf of Northern Railway

Parties involved: Contractor— Afcons Infrastructure Ltd, India; Designer—WSP Finland Ltd with subconsultant Leonhardt & Andrä und Partner, Germany 

Timeframe: Started in 2005;  the arch was connected in March 2021; estimated completion–in 2022

Bridge Challenges

Connecting the arch 

Pekka Pulkkinen, Design Director, WSP in Finland

The Chenab Bridge is a major achievement—for all the bridge designers and builders involved in the project. The erection of the arch, a truly memorable moment, represents a great execution of engineering expertise. Cooperation between the design team and contractor has been essential for the project’s advancement. The challenges in the project have been handled together, thereby facilitating the successful solutions. 

The steel arch halves were connected in late March 2021, marking years of commitment, as many of the designers have been working on the project from the beginning, year 2005. The bridge has numerous design challenges, such as the erection of the steel arch by cable crane, the bridge’s huge dimensions, and the special design requirements—redundancy of the arch, the earthquake load and blast load effect. 

The erection of the steel arch segments was done with a suspension cable crane, which can lift one 35-ton steel block at a time. The arch was erected by cantilever method. Halves were hung on both sides with steel cables that were attached to the built foundations. All the steel blocks are bolted together. Steel truss pillars will be installed next on top of the connected arch. The steel superstructure of the bridge will be launched over the steel truss piers from both directions, and the joining will take place in the middle of the arch. Finally, rails will be installed on the deck for train traffic. The approach portion of the bridge has already been completed.