优势裂隙倾角对反倾岩质边坡变形影响分析

Influence of Fissure's Dip Angle on Deformation of Anti-dip Rock Slope

通过底摩擦实验试验在前人的基础上进一步研究优势裂隙组的倾角变化对反倾岩质边坡变形破坏影响。将反倾岩质边坡变形破坏区域分为剪切滑移区、倾倒破坏区以及倾倒变形影响区。实验试验结果及理论分析表明:①裂隙的存在使得岩体呈现非均质各向异性的特性且裂隙的倾角不同对岩体强度的折减也是不同的,当裂隙倾角θ满足关系式:θ∈[π-(α+50°),π-(α+40°)](α为岩层倾角)时,对反倾岩质边坡的整体强度折减达到最大;②当裂隙倾角θ对反倾岩质边坡的岩体强度折减达到最大时,剪切滑移区在反倾岩质边坡的破坏区域中的占比达到最大,与之呈正相关;③反倾岩质边坡发生最终破坏需要的时间主要与前缘以剪切破坏为主导的剪切滑移区的占比有关,剪切越多区的占比越大,边坡发生破坏所需时间越多,反之边坡破坏所需时间越少。

Based on the bottom friction experiment and previous researches,the effect of the dip angle of the dominant fissure set on the deformation and failure of the anti-dip rock side slope was studied.The deformation and failure zone were divided into shear slip zone,toppling failure zone and toppling deformation zone.The experimental results and theoretical analysis are:(1) the non-unit anisotropy of rock body is caused by fracture and different dip angle of the crack can result in different reduction for rock mass strength.When the dip angle satisfies the relation expression:θ∈[π-(α+50°),π-(α+40°)](α is the dip angle of rock stratum),the maximum overall strength reduction of the anti-dip rock slope shall be reached;(2) when the reduction from fracture slope angle reaches the maximum for the rock mass strength of the anti-dip rock side slope,shear slip zone also takes up the most of the failure area in the anti-dip rock side slope,where the angle and the shear slip zone proportion have a positive correlation;(3) and the time required for ultimate failure of the anti-dip rock side slopes is mainly related to the proportion of shear slip zones dominated by shear failure in the front edge.More shear means more shear slip zones,which will prolong the time for side slope failure,and vice versa.