Coupling calculation of seismic displacement of bridge abutment based on failure mechanism of slope

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.