地震作用下顺层岩质边坡动力可靠度

Dynamic Reliability Analysis on Rock Slopes Under Earthquake

针对地震的动力特性以及岩体强度参数的随机性,提出计算地震作用下顺层岩质边坡动力可靠度时程的方法,并提出以最小平均安全系数和平均大失效概率作为联合评价指标来评价顺层边坡的整体稳定性。首先,建立了顺层岩质边坡地震响应的分析模型,根据得到的岩体应力地震响应求出了顺层岩质边坡的动力安全系数时程曲线;建立了顺层岩质边坡极限状态方程,并运用JC法求出了边坡的失效概率时程曲线。最后,求出了顺层岩质边坡的最小平均安全系数和平均大失效概率。算例分析表明,与传统方法相比,采用最小平均安全系数和平均大失效概率来作为评价顺层岩质边坡稳定性的综合指标,能更安全地评价边坡的稳定性。

For the dynamic characteristics of the earthquake and the randomness of rock＇s strength parameters,a new method is put forward to calculate the time-history of dynamic reliability of bedrock slope under earthquake. The minimum average safety factor and the average big failure probability are considered as the combined evaluation index to evaluate the overall stability of bedrock slope. First,analytical model is established to analyse the seismic response of bedrock slope and the time-history curve of dynamic safety is solved according to the earthquake response of the rock slope,the limit state functions of bedrock slope is established and the time-history curve of the failure probability is solved with JC method. Finally,the minimum average safety factor and the average big failure probability is solved. The numerical example shows that,compared with traditional methods,we can evaluate the overall stability of bedrock slope more safely when the minimum average safety factor and the average big failure probability are considered as the combined evaluation index to evaluate the overall stability of bedrock slope.