用点安全系数分析滑坡的空间滑动机理

Application of Point Safety Factor to Study on Spatial Sliding Mechanism of Landslide

为定量描述滑坡的空间滑动机理,建立了滑坡的三维数值模型,通过数值计算,获得了滑带单元的三维应力状态和滑动方向.定义单元点安全系数为滑带抗剪强度与滑带上与滑动方向平行的剪应力之比,分析点安全系数在滑带上的空间分布特征,可评价滑坡的空间滑动机理.研究表明,点安全系数在滑带上呈连续分布,分布规律与宏观地质判断确定的滑坡滑动机理一致,可以用点安全系数作为滑坡空间滑动机理的量化评价指标.

In order to describe quantitatively the spatial sliding mechanism of landslides,a 3-D numerical model was set up,and spatial stress states and sliding directions of elements in slide zone were obtained.The ratio of shear strength to shear stress paralleling to sliding direction was defined as point safety factor of element.Therefore,the spatial sliding mechanism of a landslide can be evaluated through analyzing the spatial distribution characteristic of point safety factor in a slide zone.The research indicates that the distribution of point safety factor in a slide zone is continuous and shows the same regularity as sliding mechanism given by macrogeologic analyses.As a result,point safety factor can be taken as a quantitative assessment index of spatial sliding mechanism of landslides.