软弱夹层物性特征对排土场边坡稳定性的影响研究

Study on the Influence of Physical Properties of Weak Interlayer on the Stability of Dump Slope

软弱夹层作为边坡岩体系统的薄弱环节,对控制边坡的稳定性具有关键作用。为研究软弱夹层的物性特征对排土场边坡稳定性的影响,以河曲旧县露天煤矿为工程背景,分别计算了天然状态、饱水状态、含软弱夹层时边坡的稳定性;基于此,探讨了软弱夹层赋存深度、倾角、厚度等物性特征对边坡稳定性的影响。结果表明:天然状态下排土场边坡处于稳定性状态,饱水状态下边坡稳定性处于基本稳定状态,边坡含有软弱夹层时稳定性难以得到保证;软弱夹层的存在会改变排土场边坡的潜在滑移面形态,由圆弧形破坏向上部类圆弧下部斜线的破坏形态转变;随着软弱夹层深度的增加排土场边坡安全系数逐渐增加,且存在临界深度;边坡安全系数随着软弱夹层倾角的增加逐渐降低,呈一次函数关系;边坡安全系数随着软弱夹层厚度的增加逐渐降低,呈二次函数关系。

The weak interlayer acts as a weak link in the slope rock mass system and plays a key role in controlling the stability of the slope.In order to study the influence of the physical characteristics of the weak interlayer on the slope stability of the dumping site,the stability of the slope in the natural state,the saturated state and the weak interlayer is calculated based on the engineering background of the Hequ old county open pit mine;The effects of physical characteristics such as depth,inclination and thickness of weak interlayer on slope stability are discussed.The results show that the slope of the dump is in a stable state under natural conditions,and the stability of the slope is basically stable under saturated conditions.When the slope contains a weak interlayer,the stability is difficult to be guaranteed;the existence of the weak interlayer changes the potential slip surface shape of the dump slope,and the circular shape destroys the failure mode of the lower arc of the upper arc;The increase of the depth of the weak interlayer increases the safety factor of the slope of the dumping site,and there is a critical depth.The safety factor of the slope decreases with the increase of the dip angle of the weak interlayer,showing a linear relationship.The slope safety factor varies with the thickness of the weak interlayer.The increase gradually decreases and is in a quadratic function relationship.