非饱和黄土边坡直立性影响因素分析

Analysis of influence factors on uprightness of unsaturated loess slope

通过Fredlund&Xing模型估算某区域非饱和黄土的水土特征曲线,再运用Midas/GTS对延安地区非饱和黄土物理力学性质进而数值模拟,对影响黄土直立性的各个因素进行敏感性判别,最后通过Lognormal分布函数拟合得出非饱和黄土边坡直立性经验公式。主要得出的结论为:基质吸力是通过影响黄土黏聚力进而影响黄土直立性。通过敏感度分析可得出:黄土极限高度对黏聚力最为敏感,黄土边坡坡角次之,内摩擦角最不敏感。随着黏聚力和内摩擦角的增大,黄土极限高度H的敏感度近似呈lg曲线。

In this paper,the Fredlund&Xing model is used to estimate the soil and water characteristic curve of unsaturated loess in a certain area,and then Midas/GTS is used to numerically simulate the physical and mechanical properties of unsaturated loess in Yan’an area,and the sensitivity of various factors affecting the uprightness of loess is discriminated.Finally,through the Lognormal distribution The empirical formula of uprightness of unsaturated loess slope is obtained by function fitting.The main conclusions are as follows:Matrix suction affects the uprightness of loess by affecting the cohesion of loess.Through sensitivity analysis,it can be concluded that the limit height of loess is the most sensitive to cohesion,followed by slope angle of loess slope,and the angle of internal friction is the least sensitive.With the increase of cohesion and internal friction angle,the sensitivity of the limit height H of loess is approximately lg curve.