深水桥梁在地震作用下同时会受到波浪作用,研究地震和波浪联合作用对深水桥梁动力响应的影响具仃重要意义。该文利用辐射波浪理论求解桥墩地震动水压力,并采用绕射波浪理论考虑波浪作用,建立地震和波浪联合作用下的深水桥梁动力响应分析方法;首先对深水桥梁分别进行地震和波浪作用下的动力响应分析,最后进行地震和波浪联合作用下的桥梁动力响应分析。分析得到,地震动水压力作用增大了桥梁结构的动力响应;波浪沿桥梁不同方向入射时波浪力对桥梁结构的动力响应影响有所不同,相对地震作用而言波浪影响较小;波浪和地震联合作用时桥梁结构的动力响应并不是两者单独作用下动力响应幅值的简单累加。由此得出结论:深水桥梁动力响应分析应合理考虑地震和波浪作用。
Earthquake and wave may be simultaneously applied to bridges in deep water, it is important 1o analyze the dynamic responses of bridges under combined earthquake and wave actions. A hydrodynamic pressure formula for bridge piers is established using radiation wave theory, and the wave action is considered by difiraction wave theory. Method of dynamic response analysis for bridges in deep water under combined actions of earthquake and wave is established. Dynamic response analyses of a bridge are conducted under separate earthquake action and wave action, respectively. Considering combined actions of earthquake and wave, the dynamic responses of the bridge in deep water is then analyzed. The results indicate that the dynamic responses of the bridge in deep water are augmented because of earthquake induced hydrodynamic pressure. The effect of wave action on the bridge changes with different wave incident directions, but the wave action influence on the bridge is smaller than the earthquake action influence. Dynamic responses of bridge in deep water under separate earthquake and wave actions are nonlinear and cannot be combined by superposition.