Seismic Performance of Tall Pier Bridges Considering Soil-Structure-Interactions

Abstract:

This paper investigated the effects of soil layers on the ground motions and seismic performance of tall pier bridges， using finite element models incorporating nonlinear p-y springs. The results show that when proper motions are selected as inputs， the seismic shear force and bending moment of tall piers could be evaluated by linear-elastic six-spring models with acceptable accuracy under earthquake records with a comparatively low intensity. However， when large input intensities are considered， this type of models will overestimate the shear force demands. Furthermore， the displacement demands of pile cap， which serves as an indicator of concrete piles， are always significantly underestimated by the six-spring models， leading to unconservative design for pile foundations.