Volume 2 - Issue 3, May - June 2026

Underpass bridges are essential transportation structures designed to facilitate uninterrupted traffic movement in urban and highway networks. These structures are continuously subjected to vehicular loads and are also vulnerable to seismic effects, particularly in earthquake-prone regions. The present study investigates the structural performance of reinforced concrete (RCC) boxtype underpass bridges subjected to static vehicular loading and seismic loading conditions. Three-dimensional numerical models with span lengths of 5 m, 10 m, and 15 m were developed and analyzed using appropriate structural analysis software in accordance with IRC and IS 1893:2016 provisions. Parameters such as displacement, base shear, natural time period, frequency, acceleration response, and stress distribution were evaluated. Comparative analysis between pier bridge and box bridge configurations was also carried out under seismic loading conditions. The results indicate that the box bridge configuration provides superior seismic resistance with approximately 9.44% lower displacement compared to the pier bridge. The 10 m span bridge demonstrated the most balanced structural performance with minimum displacement, moderate base shear, and stable dynamic characteristics. The study concludes that moderate-span RCC box-type underpass bridges are structurally efficient and suitable for seismic-prone regions.

Mr.Om J. Gabhane, Dr.B.H.Shinde,"Comparative Study on Structural Performance of Underpass Bridge With Seismic Loads" International Journal of Advanced Multidisciplinary Research and Educational Development, V2(3): Page(247-253) May-June 2026. ISSN: 3107-6513. www.ijamred.com. Published by Scientific and Academic Research Publishing.