软硬互层反倾岩质边坡倾倒变形深度研究

Study on the depth of overturning deformation of soft and hard interbedded rocky slopes

软硬互层反倾岩质边坡破坏类型复杂,影响因素众多,难以防治。为进一步探明此类边坡倾倒变形深度的变化规律,利用二维颗粒流方法并结合重度增加法,研究了不同岩性组合对倾倒变形深度的影响规律。模拟结果表明:(1)边坡倾倒变形过程中产生1~3级破裂面,且破坏模式主要有倾倒-滑移破坏、倾倒-弯曲和倾倒-折断3类,破裂面级数和破坏模式随岩层厚度增大而逐渐变化。(2)随着硬岩层厚的增大,软岩层厚为0.5 m的边坡深层主破裂面、第一次级破裂面和第二次级破裂面深度逐渐增大,而软岩层厚为1.0 m的边坡深层主破裂面、第一次级破裂面逐渐减小,第二次级破裂面不发育。(3)总体上,随着软岩层厚的增大,硬岩层厚为0.5 m和1 m的边坡深层主破裂面和第一次级破裂面深度逐渐减小,且影响程度前者大于后者。

Complex types of damage to soft and hard interbedded rocky slopes with many influencing factors,difficult to prevent and control.In order to further investigate the changes in the depth of overturning deformation of such slopes,the influence of different lithological combinations on the depth of overturning deformation was investigated using the two-dimensional granular flow method combined with the increasing gravity method.The simulation results show that:(1)Slope tipping deformation process produces 1~3 levels of rupture surface,and the damage mode mainly has tipping-slip damage,tipping-bending and tipping-fracture 3 categories,the number of rupture surface levels and damage mode gradually changes with the increase of rock thickness;(2)As the thickness of the hard rock layer increases,the depth of the deep main rupture surface,the first stage rupture surface and the second stage rupture surface gradually increases for the soft rock layer with a thickness of O.5m,while the deep main rupture surface,the first stage rupture surface gradually decreases for the soft rock layer with a thickness of 1.Om,and the second stage rupture surface is not developed;(3)In general,as the thickness of the soft rock layer increases,the depth of the deep main rupture surface and the first grade rupture surface of the slope with hard rock layers 0.5m and 1m thick gradually decreases,and the former has a greater impact than the latter.