基于Bishop条分法的多点多向地震动作用下边坡稳定性分析

以人工合成的多点、多向地震加速度时程作为地震动输入,基于Bishop条分法推导了地震边坡稳定安全系数的表达公式。在此基础上,针对某一具体算例,分析了不同地震峰值加速度下的不同坡高边坡稳定安全系数的变化规律,并与单点、单向地震动输入的结果进行了对比。结果表明,对于本文给出的算例,在坡高与地震峰值加速度都相同的条件下,多点、多向地震作用下的边坡安全系数要大于单点、单向作用下的安全系数;当坡高小于30 m、地震峰值加速度小于0.1 g时,多点、多向地震动作用下的边坡安全系数与单点、单向相差不大;当坡高大于30 m、地震峰值加速度大于0.1 g时,多点、多向地震动作用下的边坡安全系数相对单点、单向要小36%以上,此时边坡稳定性评价必须考虑地震动的多点、多向特性。

Stability of Slope under Multi-point and Multi-direction Seismic Motion Based on Bishop Method

With the input of the artificial multi-point and multi-direction seismic motion,the formula on safety factor of slope under earthquake is deduced based on the Bishop method.For a specific example,the safety factor is analyzed in condition of different slope height and seismic acceleration amplitude,which is compared with the case with the uniform input.It is shown that the safety factor under the multi-point and multi-direction seismic motion is larger than the one under the single-point and single-direction seismic motion.It is revealed that when slope height is lower than 30m and seismic acceleration amplitude is less than 0.1g,the results of the safety factors of different seismic motion inputs are similar,but when slope height is higher than 30m and seismic acceleration amplitude is more than 0.1g,the maximal change rate is beyond 36%,when the input of multi-point and multi-direction seismic motion should be considered for slope stability evaluation.