中文摘要：

采用集中质量模型模拟桩-土相互作用，通过Morison方程和辐射波浪理论分别考虑桩基和桥墩动水压力效应，并通过桥墩构件损伤模型定义桥梁结构整体损伤准则，建立了多介质体作用下桥梁结构的地震损伤分析方法。首先对近海连续刚构桥分别进行不同水深和不同土层剪切波速条件下桥梁地震损伤分析，然后进行多介质体作用下桥梁结构的地震损伤分析。结果表明：地震作用下水-结构相互作用增大了桥梁的损伤指数，考虑桩-土相互作用减小了桥梁的损伤指数；多介质体作用下土层剪切波速较小时，水深对桥梁损伤影响相对不明显；桥梁地震损伤程度主要与地表地震动频谱特性相关；桥梁结构以横桥向损伤破坏为主。

英文摘要：

By simulating the pile-soil interaction by the lumped mass model, considering piles and piers by Morison equation and radiation wave theory, the damage criterion for bridge hydrodynamic pressure of structures is defined based on the damage model for reinforced concrete members and seismic damage analysis method for bridges under multiple mediums action is established. The seismic damage analysis of bridges is conducted by considering separate waterstructure interaction, pile-soil interaction and multiple mediums action. The results indicate that the damage index of bridge is augmented by the water-structure interaction and reduced by the pile-soil interaction. The hydrodynamic pressure hardly affects the bridge damage when the shear wave velocity of soil is small under multiple mediums action. In addition, the seismic damage extent is mainly affected by the surface seismic spectrum characteristics and transverse failure is dominating in the damage modes of bridges.