The new Shimla Bypass cable-stayed bridge forms part of the 27 km four-lane development of the proposed Shoghi – Shimla - Dhalli bypass of National Highway 22 in the northern state of Himachal Pradesh, India.
At the onset of the project, Systra-IBT was engaged by Chetak Enterprises to undertake concept development, detailed design and construction engineering of the cable-stayed spans. The development of the concept was undertaken using a detailed Tekla model incorporating the drone survey results of the valley, which was an essential tool used to identify the optimal pier locations given the complex valley geometry. The use of Tekla is now being extended into the final and construction phases of the project.
The final arrangement of the bridge consists of an asymmetrical 3-span cable-stayed bridge supporting a 26.9m wide dual carriageway, with spans of 100m - 318m - 168m. The bridge will be built in a balanced cantilever, in which prefabricated segments are progressively erected using a lifting frame on the deck. The final deck level is over 200m above the valley below. Each carriageway is supported by a plane of stay cables and consists of a composite structure of steel edge girders and floor beams with precast concrete deck panels.
The single mast concrete pylons house anchorages for the two planes of cables. The pylons reach a height of about 215m above the valley, with the upper 40m reserved for the composite steel-concrete stay anchorage housings.
The project is ongoing, however the communication through Trimble connect between teams was essential for solving issues. Systra-IBT was engaged by Chetak Enterprises to undertake concept development, detailed design and construction engineering of the cable-stayed spans.
Tekla Structures and Trimble Connect were used to develop the complex 3D geometric model and the coordinated Tekla drawings for all the structural elements.