Influence of Actual Site Soil Layers on Pounding of a High-Pier Bridge Occurred between Deck and Abutment

Abstract

This study aims to determine the pounding probability of a continuous rigid bridge with high piers and long span at the actual site soil under the action of an earthquake. Finite element models of the bridge are built to analyze separation length. The effect of the actual site soil on seismic wave propagation from the bedrock to the pier and the abutment foundation is considered using DEEPSOIL software. A pounding probability analysis method under multi-support seismic excitations with bedrock peak acceleration as the strength index is proposed. The pounding probability of the continuous rigid bridge with high piers and long span under multi-support seismic excitations is analyzed using the proposed method. Meanwhile, a comparison analysis of the pounding probability results under uniform excitations without considering the influence of the actual site soil is performed. The study indicates that the required width of the expansion joint under uniform excitation is larger than the multi-support excitation with the increase in bedrock peak acceleration. With the increase in the width of expansion joint and the acceleration peak, the probability of pounding at a single abutment and at two abutments under multi-support excitation is gradually less than uniform excitation. Therefore, the actual site soil must be considered when determining the width of the expansion joint of a continuous rigid bridge with high piers and long span.