露天矿山岩质边坡软弱夹层赋存状态影响边坡稳定性规律研究

软弱夹层作为一种典型地质结构是影响整个边坡安全稳定性的关键因素。为了更好地分析软弱夹层的性质及对边坡稳定性的影响，针对某含软弱夹层矿山露天岩质边坡，运用正交对照法对边坡软弱夹层的埋深、倾角、数量及夹层间结构面间距等4种夹层赋存状态，进行变量4×4正交模拟，揭示了不同赋存状态下边坡稳定性及变形规律。研究结果表明，1）边坡软弱夹层的赋存状态对边坡稳定性有显著影响，随软弱夹层埋藏深度的增加边坡安全系数随之增大，当埋深达到一定值后，边坡安全系数趋于稳定；2）随着软弱夹层角度的增大，破坏机制表现为层间错动、顺层蠕滑和沿软弱结构面的剪切滑移递进式变化；3）随软弱夹层层数增多，边坡整体性下降致使变形不均匀，边坡安全系数减小，水平方向位移增大；4）对比同等埋深结构面间距较小的软弱夹层边坡，结构面间距对边坡安全系数的影响较小。

Influence of the occurrence state of soft interlayer on the rock slope of open-pit mine

As a typical geological structure, a soft interlayer is a key factor affecting the safety and stability of the entire slope. In order to better analyze the properties of soft interlayers and their influence on slope stability, the orthogonal control method was used to simulate four occurrence states of the sandwich depth, inclination angle, quantity and structural surface spacing between the layers of the slope with a soft interlayer in a mine open-pit rock slope. A 4×4 orthogonal simulation was carried out and the stability and deformation law of the slope were revealed under different occurrence states. The results show that: 1) the occurrence state of the soft and weak interlayer of the slope has a significant impact on the stability of the slope. The safety factor of the slope increases with the increase of the burial depth of the soft interlayer, and the safety factor tends to stabilize after the burial depth reaches a certain level. 2) With the increase in the angle of the soft interlayer, the failure mechanism is manifested as interlayer mismotion, creep slip along the layer and progressive change of shear-slip along the soft structural surface. 3) The increase in the number of soft interlayer layers leads to an overall decline in the slope with uneven deformation, a decrease in the safety factor of the slope, and an increase in horizontal displacement. 4) For the soft sandwich slope with the same buried depth, structural surface spacing has less influence on the slope safety factor when the spacing is small.