砂泥岩互层缓倾切向边坡应力特征及变形机理研究

Study on Stress Characteristics and Deformation Mechanism of Sand-mudstone Interbedding Gently Dipping Tangential Slope

为了更好地分析砂泥岩互层缓倾切向边坡的变形机理情况,以西南某红层边坡为例,基于数值模拟软件建立了软硬互层三维切向地质模型,探讨了边坡开挖、支护后的应力场和位移场。结果表明:砂泥岩互层切向边坡开挖后,边坡XX方向应力和YY方向应力出现了沿切向的锯齿形状,应力分布受岩层切向与互层岩性差异的影响较大,ZZ方向应力几乎不受影响;切向岩层受侧向约束的影响,致使边坡变形出现了层次性,且X方向较为显著,Y方向次之,Z方向最弱;边坡整体变形趋势类似于均质岩坡,呈现圆弧滑动趋势;边坡采用框架锚杆支护,仅起到构造护坡作用,边坡的变形和应力状态并未发生实质性的影响。研究成果对砂泥岩缓倾切向边坡的变形预测和支挡防护具有一定的工程借鉴意义。

In order to better analyze the deformation mechanism of the gently dipping tangential slope with interbedding sand and mudstone,taking a red bed slope in the southwest as an example,a three-dimensional tangential geological model of soft and hard interbedding is established by the numerical simulation software.The stress field and displacement field after excavation and support of the slope are discussed.The results show that after excavation of the tangential slope of the sand-mudstone interbedding,the stress in the XX direction and the stress in the YY direction of the slope appear a zigzag shape along the tangent.And the stress distribution is greatly affected by the difference between the rock stratum tangent and interbedding lithology,and the stress in the ZZ direction is almost unaffected.The tangential rock stratum is affected by the lateral restraint to cause the slope deformation to appear hierarchical,and the X direction is more significant,the Y direction is second and the Z direction is the weakest.The overall deformation trend of the slope is similar to that of a homogeneous rock slope,showing a circular arc sliding trend.The slope is supported by frame anchor bolts,which only plays the role of structural slope protection.The deformation and stress state of the slope have no substantial effect.The research results have certain engineering reference significance for the deformation prediction and support protection of sand-mudstone gently dipping tangential slopes.