Impact of span variations on PSC I-girder bridge sub-structures as per IRC standards

The design and analysis of bridge sub-structures play a critical role in ensuring the safety, functionality and durability of bridge super-structure. In this study, the sub-structure of Pre-stressed Concrete (PSC) I girder bridges is analysed, focusing on varying span lengths, c/c distance of girders and pier heights. The study is conducted following guidelines set out in IRC-114 and IRC 78:2020 which provide updated specifications for the design of road bridges. These guidelines reflect advancements in materials, load consideration and structural behaviours, ensuring modern standards for performance and durability of bridges. The research aims to understand how changes in span length, pier heights affect the overall stability, load distribution of PSC-I girder bridges. The sub-structure, which includes piers and foundations, must withstand vertical and horizontal loads while maintaining balance between superstructure and sub-structure forces. The critical interaction between span length (25m and 30m), pier diameter, pier height is examined bending moments under the live load, seismic load, and dead loads. In this paper, the analysis is done using STAAD-PRO software.