DYNAMIC RESPONSE ANALYSIS OF CABLE-STAYED AND GIRDER BRIDGES SUBJECTED TO VEHICULAR LOADS AS PER IRC STANDARDS

Abstract

The dynamic response analysis of bridges is a crucial aspect of structural engineering, particularly for cable-stayed and girder bridges that are frequently subjected to moving vehicular loads. As traffic intensity and vehicle loads increase, accurate assessment of structural performance under dynamic conditions becomes essential to ensure safety, serviceability, and durability. This study focuses on the comparative evaluation of cable-stayed and girder bridges when subjected to vehicular loading as per the provisions of the Indian Roads Congress (IRC:6-2017). Finite Element Analysis (FEA)-based numerical modeling is adopted to simulate the real-time behavior of bridges under moving loads such as the IRC Class 70R vehicle. The study investigates parameters including natural frequencies, mode shapes, displacement, bending moments, shear forces, cable forces, and vibration characteristics. The interaction between vehicle loads and bridge dynamics is analyzed to identify critical responses, resonance effects, and performance differences between the two bridge types. The results provide insights into structural stability, load distribution efficiency, and overall dynamic performance, contributing to improved design guidelines and enhanced structural safety of highway bridges in India.