地震作用下桥台滑移计算方法及应用

Calculation Method and Application of Abutment Slipping Under Earthquake

针对汶川地震中大量桥台出现局部坍塌,产生永久滑移现象,提出了地震作用下桥台滑移计算方法。传统方法单一采用拟静力抗震稳定性安全系数,并不能准确评定桥台的动力稳定性,为此将桥台滑移地震动力响应分析与稳定系数分析方法相结合,通过采用毕肖普法计算桥台岸坡上潜在滑动面的稳定系数,对其中稳定系数小于1.25的瞬时超载滑移体,通过时间积分计算潜在滑动体的滑移量。最后结合算例,并通过计算探讨了滑移体各力学参数对桥台地震位移及地震性能的影响。

In view of this situation that a large number of partial collapse of the abutment have permanent slip phenomenon in Wenchuan Earthquake, the calculation method of abutment slipping under earthquake is put forward. Traditional methods adopt the safety factor of single quasi-static seismic stability, which can not assess the dynamic stability of abutment for the slipping accurately, then the analysis of abutment seismic dynamic response is combined with the analysis of stability coefficient, through the Bishop method to calculate the stability coefficient of potential slipping surface of slope, for the instantaneous overloading slipping body in which its stability coefficient is less than 1.25, the potential slip volume of slipping body is calculated by the time integral. Finally, the effects of mechanical parameters of the slipping body on the displacement and seismic performance of the abutment are discussed by taking an example and calculating.