随机场模型下相关距离及参数变异系数对边坡稳定可靠度的影响

由于土体的不均匀性和不确定性,土性参数在空间上表现为各向异性。为了研究土性参数各向异性对边坡可靠度的影响,采用C++语言通过局部平均法对二维随机场进行离散,得到协方差矩阵;输入参数的均值与标准差,建立了边坡随机场计算模型。结合有限差分强度折减法和响应面法与Monte-Carlo法,对比分析了模型相关距离以及土体黏聚力变异系数对边坡可靠度的影响规律。结果表明:根据随机场计算模型,在相同土体黏聚力变异系数下,随模型相关距离增大,边坡失效概率变化随之增大;在随机场计算模型相关距离相同时,边坡失效概率随着土体黏聚力变异系数的增大而呈现出上升趋势;相较与水平方向,随机场计算模型中垂直方向的相关距离变化对可靠度的影响程度更为明显。

Influence of Correlation Distance and Parameter Variation Coefficient on Stability Reliability of Slope under Random Field Model

Because of the heterogeneity and uncertainty of soils， soil parameters are anisotropic in space. In order to study the influence of soil parameter anisotropy on slope reliability， the two-dimension random field is discretized by the local average method with C + + language to obtain the covariance matrix. With the mean value of the parameters and the standard deviation input， the calculation model of slope random field was established. With combination of the finite difference strength reduction， the response surface method and the Monte-Carlo method， the influencing rule of the correlation distance in the model and the soil cohesion coefficient on slope reliability was analyzed. The results showed that with the calculation model of the random field， the slope failure probability increases with the increase of the correlation distance under the same variation coefficient of soil cohesive force in the model. The slope failure probability shows an upward trend along with the increase of the variation coefficient of the soil cohesive force under the same correlation distance in the calculation model of random field. Compared with the horizontal direction， the influence of the correlation distance variation on the slope reliability of the calculation model is more obvious in the vertical direction.