基于正交试验—蒙特卡罗法的边坡破坏概率研究

Research on Failure Probability of Landslide Based on Orthogonal Test and Monte Carlo Method

研究边坡稳定性的影响因素对边坡治理具有重要意义,提出将正交试验法和蒙特卡罗法相结合,确定影响边坡稳定性的主要因素及其相应影响程度。首先采用正交试验法分析各相关因素对边坡稳定性影响的敏感性,给出影响因素的排序,以得出稳定性主导因素;然后考虑次要因素的随机性,运用蒙特卡罗法进一步研究边坡在主要因素作用下失稳破坏的概率,并揭示主要因素对边坡稳定性的影响规律。以某边坡为例,研究了地震、库水位、岩土体内摩擦角和粘聚力等4个因素对边坡动力稳定性的影响。结果表明,对该边坡稳定性的影响由大到小排序依次为地震、库水位、内摩擦角、粘聚力;边坡破坏概率随地震水平加速度系数或库水位的增加而逐渐增大,当地震、库水位叠加作用时,边坡极度危险。研究成果可为边坡支护方案选择提供依据。

The research of influencing factors of slope stability plays an important role in slope treatment.Combined the orthogonal test and Monte-Carlo method was proposed to determine the dominant factors and their corresponding incidence of the slope stability.Firstly,orthogonal test was adopted to analyze the sensitivity of the related factors on the slope stability and obtain the dominant factors of slope stability.Then in order to review the influence patterns of dominant factors on the slope stability,the Monte-Carlo method was used to study the slope failure probability considering the randomness of these factors.Taking the slope for an example,the influence of soil behavior parameters,earthquake and reservoir water on the dynamic stability of the slope was studied.The results show that the order of the factors affecting the slope stability is sorted as earthquake,reservoir water level,internal friction angle,cohesive force;the slope failure probability is gradually increasing with the increase of earthquake acceleration coefficient or the reservoir water level.In addition,the slope is extremely dangerous under the combined action of earthquake and reservoir water level.The research provides a theoretical basis for the selection of slope supporting scheme.