滑带土力学性质及其对滑坡的控制机理研究

Physical and mechanical properties of sliding-zone soil and mechanism of its action on landslide deformation

为探究滑带土对土质滑坡的控制机理,剖析了部分滑坡滑带土的组成成份和影响滑带土物理力学性质的因素,并将滑带的形成过程与滑坡相应的发展阶段联系起来,揭示了滑带土对滑坡的控制机理。将影响滑带土强度的主要内因归结为含水量、粒度组分和矿物成份;主要外因为地下水的浸泡、埋藏深度和滑面剪切作用。将滑带的演化过程分为3个阶段:粉质黏土的形成,塑性变形及局部破坏和剪切面整体贯通。滑带土力学强度的降低,破坏了滑带中抗滑力与下滑力的平衡状态,产生剪切破坏面,因而导致滑坡的滑动。

In view of the important role of sliding-zone soil during the development of soil slope, the compositions of some sliding-zone soil of landslide are analyzed to research the influential factors of its physical and mechanical property. The mecha-nism of its action on landslide is revealed by connecting the forming process of sliding zone with the corresponding development stages of landslide. As a result, the water content, grain size and mineral compositions can be summarized as the main internal causes affecting the strength of sliding-zone soil, and the groundwater soak, buried depth and sliding surface shearing can be summarized as the main external ones. Furthermore, the evolution process of sliding zone is divided into three stages including the formation of the silty clay, plastic deformation and local failure, as well as overall penetration through of shear plane. Due to the strength reduction of sliding-zone soil, the equilibrium state between anti-slide and downslide is broken, resulting in the shearing surface failure, even in sliding of landslide.