Seismic Vulnerability Assessment of Multi-arch Gallery Masonry Bridges Adopting Different Seismic Analysis Procedures

Abstract

India has one of the longest rail networks all over the world. The Indian railway network consist of many heritage bridges which are still in service over span of 100 years. Some of these heritage bridges are located in the very high seismic zone which is threat to their structural integrity. Therefore, it is necessary to assess the performance of these bridges for the earthquake loading. For this purpose, this paper attempts to predict the seismic vulnerability of the two multi arch gallery bridges of UNESCO recognised Kalka Shimla Mountain Railway. In this paper, three dimensional numerical models of the bridges were developed in ABAQUS finite element environment. The macro-modelling strategy was followed along with the concrete damage plasticity model as constitutive model for stone masonry. Further, the seismic performance of the bridges was estimated by nonlinear static analysis and incremental dynamic analysis procedures. The nonlinear static analysis was performed adopting two lateral loading patterns and incremental dynamic analysis was performed using 30 accelerograms. The 30 accelerograms were matched with the site-specific spectra and then scaled to different level of peak ground acceleration. The results from the nonlinear static analysis and incremental dynamic analysis were presented in terms of control node displacement and location of tensile damages. Lastly, the comparison between nonlinear static analysis results and incremental dynamic analysis results were showed that confirms, incremental dynamic analysis results are more significant at very high computational time consumption.