Seismic Behavior of Bridge Piers Considering Fluid-Structure-Soil Interaction

摘要

Seismic response of the bridge piers to horizontal ground motion is investigated for various cases: rigid and flexible foundation, without and with water. The purpose of this study is to evaluate the fluid-structure interaction and soil-structure interaction effects on the seismic response of the circular cylinders. The fluid-structure interaction is simulated by added mass approach and the soil supporting the massless foundation modeled as spring-damper elements is used to simulate soil-structure interaction. The focus is placed on gauging the significance of physical parameters that affects the seismic response of the piers. An equivalent SDOF system that the pier is simplified as a single lumped-mass model is utilized to investigate the effects fluid-structure-soil interaction on dynamic properties of the piers. The results indicate that the effects of fluid-structure interaction are more significant for slender piers and cause an increase in deflections, shears and periods, and the effects of soil-structure interaction are more significant for squat piers and cause a decrease in deflections, shears and an increase in periods. The study shows that the fluid-structure interaction is more important for hard soil while the soil-structure interaction is more important for soft soil in fluid-pier-soil system.