蓉遵高速仁怀—赤水段大石沟边坡破坏机理模拟研究

Simulation Study on Failure Mechanism of Dashigou Side Slopein Renhuai-Chishui Part of Rongzun Expressway

以蓉遵高速仁怀—赤水段大石沟边坡为研究对象,具体探讨贵州红层边坡的破坏过程与破坏机理。该边坡为典型丹霞地貌区软硬互层结构的红层斜坡,砂岩与泥岩共分为13层。边坡坡表处软岩风化严重并有宽大裂隙与凹岩腔产生,从坡顶处时有碎石滑落堆积在坡底。为了研究重力场条件下岩体的变形、破坏和发展趋势,本研究采用岩体底摩擦模型试验结合PFC 2D数值模拟分析边坡岩体的变形、发展演变过程及其特征,得出边坡的变形演化过程为:坡脚处应力集中产生压致拉裂缝→坡缘、坡体中产生拉裂缝→裂隙贯通→发生倾倒性破坏。

This study is based on the the Dashigou slope in Renhuai-Chishui part of Rongzun Expressway and the failure process and failure mechanism of Guizhou red bed slope are discussed in detail.Dashigou slope is a typical Danxia landform red-sloping slope of the interbedded soft and hard rock beddings The sandstone and mudstone are divided into 13 layers.At the surface of the slope,the soft rock is severely weathered and has large cracks and concave rock cavities.At the top,gravel slipped and piled up at the bottom of the slope.In order to investigate the deformation,failure and development trend of the rock mass under natural gravity field conditions,the rock mass bottom friction model test and PFC 2D numerical simulation using simulated gravity field conditions are used to simulate the deformation and further development of the slope rock mass and its characteristics.The deformation evolution process of the slope are as follows:stress concentration at the foot of the slope produces pressure-induced tensile cracks→tensile cracks in the slope body and slope edge→crack penetration→dumping failure.