近水平软硬互层斜坡变形破坏机制

The mechanism of deformation and failure for the slope composed of nearly horizontal competent and incompetent intercalated rock mass strata

本文通过对某高速公路某深挖路堑边坡段天然斜坡的地质调查、钻探和有限元分析提出 ,近水平软硬互层岩层斜坡变形破坏首先发生于坡体中部硬岩层中 ,由拉应力的集中造成拉破坏 ,形成张性节理裂隙 ,逐渐向坡体顶部扩展 ,直至贯通而出露地表。暴雨期间在裂隙水和渗流水的扬压力联合作用下 ,产生滑移。应用本文的机制模型分析了垮梁子滑坡的形成机制。

In this paper , the mechanism of deformation and failure of the slope composed of nearly horizontal competent and incompetent intercalated rock strata is obtained by the finite element analysis and research drilling on the spot in nearly horizontal rock strata of some nature slope at Sichuan. In brief, the mechanism may be stated as follows. Firstly,due to tension stress concentration tension fracture is developed in the deep buried competent sandstone overlying on thick incompetent mudstone just underneath the crest . Secondly the fracture propagated upward gradually until it outcrops on the surface. Finally, during strong rainstorm, the fracture will be filled with water rapidly, and under the joint action of the static pressure of water and the up lift of seepage water, the slope starts to slide. The kua\|liangzi landslide is quoted as an example to verify the mechanism.