The Bridge on the River Chenab

Trimble’s latest project Chenab Bridge is one of the tallest and longest-spanning railway bridges of its kind in the world and it part of the new Baramulla—Srinagar—Udhampur railway in Northern India.

Trimble has provided its solutions to many complex and landmark structures around the world, including India. Among the various ongoing projects, the construction of Chenab Bridge in Jammu and Kashmir is one of the most pioneering projects employing Trimble’s technology. Chenab Bridge is part of the new Baramulla—Srinagar—Udhampur railway in Northern India, crossing the river Chenab in Kashmir valley. It is one of the tallest and longest-spanning railway bridges of its kind in the world.

Chenab Bridge – Rising from the bedrock of the Himalayas
The bridge is constructed 320 meters above the surface of river Chenab, and it stretches to a total length of 1,315 meters. The main arch of the Chenab Bridge spans across a spectacular 467 meters, making it one of the longest arch railway bridges in the world, and the deck, designed for two rail tracks, is 13.5 meters wide. Erected on Himalayan bedrock with foundations approximately 40 meters high and 50 meters wide, the arch and piers of the bridge are masses of steel trusses, while the foundations and the approach vi aduct piers are made of concrete. The arch is erected with a cableway crane, after which the deck is then launched into placed and joints assembled with a total of 600,000 bolts.

The Kashmir valley is one of the most isolated regions in India, and the mountainous and rough Himalayan terrain lacks a proper road network. The railway, and Chenab Bridge as part of it, is expected to remarkably affect the development of the region, improving accessibility and transportation for the local population. As one of the highest and largest railway bridges in the world, the bridge is also expected to become a popular tourist attraction, with footpaths and cycle trails to be built alongside it.

The Tekla intervention
Trimble’s flagship product Tekla Structures was effectively put to use from the beginning of this project. Given the tremendous scale and complexity involved in the construction, all structures, temporary cables, and related anchoring towers have been designed using Constructible Building Information Modeling (BIM). Data available in the constructible process extended the value of BIM beyond visualisation and into production which immensely benefited the onsite construction team.

Constructible BIM was also used for erection sequence planning, geometry and quality control on site. The workshop drawings and CNC data were sourced directly from the BIM model. The contractor for the project used the BIM models in close co-operation with the designer, while the third-party inspector made use of these models in the reviewing process. Use of constructible BIM also facilitated the organization of the plate material for better logistics in the difficult terrain. Further, the 3D visual models created in Tekla Structures facilitated quick and timely approvals. The project efficiency also increased, as the 3D models generated handy reports for material quantity take-off, assembly dimensions and ‘center of gravity’ for lifting and transportation. The high level of development (LOD) and accuracy of the model allowed it to be used for fabrication in the temporary workshops erected onsite.

The Chenab Bridge is set to be completed by December 2021 and we are glad that through this project we have clearly demonstrated that Constructible BIM can make even a highly intricate project less complex to design, plan and construct.

Challenges and Solutions
As the world’s leading technology solutions provider, we have developed a unique lifecycle approach to ensure our customers are able to realise the benefits of Constructible BIM and automate construction effectively and entirely. And we successfully applied this approach to Chenab Bridge project too. In consideration of the harsh and mountainous terrain and severe climate in the region, the construction team had to remain single-mindedly committed to schedule compliance, technical excellence and logistical management. Beyond the obvious geographical challenges, the project contained approximately 25,000 tons of steel detailing; the management of which was a hugely demanding task.

When we deal with such complex and large-scale projects, collaboration amongst different stakeholders is often a challenge. With Tekla software, we enabled efficient collaboration between all parties, as well as allowed the steel structures to be modelled accurately and drawings to be easily printed directly from the model for the fabrication team.

The teams involved produced tens of thousands of drawings, with members of the various parties using it daily to run files for production, management and flame cutting. The contractor on the project, Chenab Bridge Project Undertaking (CBPU), had many BIM users working on the project, and the site management used Tekla BIMsight, a professional tool for collaboration, for reviewing the model on site.

Because of this, our software was able to streamline the processes, as the entire construction workflow could combine models, check for conflicts and share information using the same easy to use BIM environment. Project participants were able to identify and solve issues already in the design phase before construction. A lot of time usually spent on identifying and rectifying the issues on site was saved due to this.

Using Tekla Structures for the Chenab Railway Bridge construction eventually made assessing information at every stage of the design project possible, while improving efficiency and productivity, and minimising the need for rework. Throughout the bridge construction process, constructible BIM proved its capabilities in various ways.

For more details, contact:
Harsh Pareek,Regional Sales Director,India and SAARC,Trimble Solutions