双向地震荷载下崩塌堆积体盲数稳定可靠性分析

Reliability analysis of collapse accumulation body stability under bi-directional earthquake excitation

为了能考虑地震双向性和岩土体参数多种不确定性,提出了地震荷载下崩塌堆积体稳定可靠性分析方法,进一步研究水平和竖向地震荷载对崩塌堆积体的可靠性影响。运用极限平衡法和拟静力法分析了双向地震下崩塌堆积体的安全稳定性,采用响应面法和JC法建立崩塌堆积体的地震极限状态方程,然后,运用盲数理论对岩土体参数进行盲数化处理,进一步推导出崩塌堆积体地震安全系数的盲数模型,最后,通过MATLAB编写相应的程序实现计算和分析结果的快速输出。分析表明:该方法计算结果更低,更偏于工程安全可靠;与水平地震荷载相比,竖向地震荷载对崩塌堆积体的稳定可靠性影响很小,仅使得安全系数和可靠度分别降低1.78%和2.78%,因此,在此种工况下,采用拟静力法进行抗震分析时可仅考虑水平地震荷载的影响。

A reliability analysis method for the seismic stability of collapse accumulation body,which both considers the bi-directional earthquake excitation and the uncertainty of rock and soil parameters,was proposed in this paper.The influence of horizontal and vertical seismic loads on the stability and reliability of collapse accumulation body was further analyzed.First,the safety and stability state of the collapse accumulation body under bidirectional earthquake was analyzed by using the pseudo static method and the limit equilibrium method,and the seismic limit state equation of collapse accumulation body was established based on the response surface method and the JC method.Then,the parameters of rock and soil were processed using the blind number theory,and the blind number model for the seismic safety factor of collapse accumulation body was further established.Finally,the corresponding program was compiled by MATLAB to realize the fast output of calculation and analysis results.The calculated results showed that:the calculation value of the proposed method is low,so it is more safe and reliable for projects.Compared with the horizontal seismic load,the vertical seismic load has little impact on the stability and reliability of collapse accumulation body,which only reduces the safety factor and reliability by 1.78%and 2.78%,respectively.Therefore,in this case,only the influence of horizontal seismic load needs to be considered when the quasi-static method is used for seismic analysis.