针对黄土-红层接触面滑坡存在的变异性、随机性、不确定性,为了充分考虑其影响因素,利用Monte-Carlo法的基本原理,结合传递系数法建立滑坡稳定性可靠性分析的状态功能函数,从而得到以失稳概率P_f和可靠性β为指标的滑坡稳定性可靠性分析结果。以天水-陇西滑坡密集带中典型的黄土-红层接触面滑坡为例,通过现场勘察、室内实验、理论分析等,分析了滑坡基本特征、岩土体性质以及影响因素。在分析滑坡形成机制的基础上,统计分析滑带土黏聚力c、内摩擦角φ得到其均值、标准差、变异系数、分布规律等,借助VC++程序设计,从而计算得到该滑坡失稳概率和稳定性可靠性。由分析结果可知,该方法得到的滑坡稳定性与传统稳定性分析方法基本一致;该方法从多角度、多指标综合分析了滑坡稳定状态,提高了滑坡稳定性评价精度。
The stability of the loess-red mudstone interface landslide which has variability, randomness and uncertainty is affected by multiple factors. In order to thoroughly analyse the factors, the Monte-Carlo method was combined with the state function of reliability analysis on landslide stabilization established by transmitting coefficient method and was introduced to obtain the reliability analysis results indexed by in- stability probability P1 and reliability β. In this study, loess-red mudstone interface landslide in Tianshui- Longxi landslide belts was taken as example, and both site investigation and laboratory experiment were applied to investigate the basic characteristics of the landslide, the properties of rock and soil and influen- cing factors. Based on the analysis of landslide formation mechanism, statistical analysis and theory analy- sis on sliding soil cohesion(c), internal friction angle(p) was conducted to get their mean values, standard deviations, variation coefficients and distribution rules with the aid of the VC++ design program, so as to calculate the instability probability P1 and reliability β. The analysis result shows that the stability of the landslide obtained bythis method is consistent with the stability analyzed by traditional analysis methods, but this method improved the accuracy of landslide stability evaluation through multi-perspective and multi-index analysis of landslide stability. Key words: loess-red mudstone interface landslide; stability; Monte-Carlo simulating method; reliability a- nalysis