Bearings for a Skew Bridge: Lessons Learnt—A Case Study

Bearings are a critical element of a bridge. Although they represent only a small part of the overall structures and the cost too is miniscule, they can potentially cause significant problems if they do not function properly. The arrangement of the bearings too plays a significant role in the proper functioning of the bridge. The present work is pertaining to a repair and rehabilitation of a damaged set of bearings on NH of a ROB in the state of Rajasthan. The bridge is over an active railway line with a span of over 41 m and skew of 56°. The analytical work carried out to identify the root cause of the damage resulted in surprising findings. It was realised that the skew angle plays a very dominating effect on the bearing forces. The arrangement too needed revision. The work under reference is presented in three parts viz., identifying damage, analysing the same and the remedial measure to cure the distress. The purpose of this paper is to understand the behaviour of large skew vis-à-vis the bearings and to propose reliable arrangement of the same to improve load transmission. MIDAS is used as a tool for simulation.