【摘要】 地震作用下桥台永久变形大小是评价桥梁基础地震稳定性的一个重要指标。首先分析地震下桥台破坏特点,提出简化桥台滑坡破坏模式,在此基础上考虑土体强度衰减效应对桥台稳定性的影响,将桥台-土体地震动力响应分析与Newmark有限滑移计算方法相耦合,提出桥台滑移计算公式。然后将计算结果与R-E方法进行对比,结果表明:提出的计算模型能较好地反映桥台-土体的破坏特点,较充分地考虑地基土软化对桥台的稳定作用,以及在一定程度上考虑桥台-土体的地震动力响应特性;土体强度衰减对桥台-滑坡体的稳定性影响很大,在计算中不可忽视。更多还原

【Abstract】 The earthquake-induced permanent displacement is an important index to evaluate the stability of bridge abutments.Firstly,the failure mechanism of abutment-soil during the quake was analyzed and its failure modes were presented.Considering the effects of soil’s strength degradation on the stability of bridge abutments based on the failure modes proposed,a coupling analytical method was presented to calculate the seismic displacement combined seismic response analytical method of abutment-soil and Newmark’s finite displacement theory.Then,comparisons were made between R-E method and that proposed in this paper.The results show that the calculation model proposed seems reasonable to reflect failure mechanisms of the abutment-soil system.It is capable of considering the significant effects of foundation softening on the stability of bridge abutments and of considering the dynamic response characteristics for abutment-soil system.The effects of soil’s strength degradation on the stability of abutment-slope are so significant that they can’t be negligible.更多还原