Seismic Vulnerability of Urban Bridges due to Liquefaction using Nonlinear Pushover Analysis and Assessing Parameters for Damage Detection

摘要

Pre-disaster planning strategies and strengthening to ensure certain degree of performance of deficient bridges can reduce the seismic risk to a great extent. Codes have been steadily moving towards performance based designs. This study aims at investigating the effect of liquefaction during earthquake on bridges founded in the soft alluvium. For this purpose, nonlinear static analysis has been used to derive fragility and vulnerability curves. A two span box girder bridge has been analysed. The bridge foundation soil strata have layers of fine sand to sandy silt deposits. The capacity and vulnerability of the bridge under normal soil and liquefied conditions have been studied. It has been observed that the time period and damping of the structure have increased. Fragility curves have been developed to assess the seismic performance of the bridge. This study will help to ensure the performance criteria/levels of the bridges and more informed pre-disaster planning strategies to avoid seismic risk and add to the existing knowledge of the concept of performance based design of RC bridges.