露天矿顺倾层状边坡稳定性的断层效应

Fault effect on stability of dip bedded slope in open pit mine

作为一种典型的露天矿山边坡,含断层顺倾层状边坡的变形破坏机理及稳定性等问题尤为复杂。结合元宝山露天矿东帮边坡工程实际,基于强度折减理论,同时考虑岩体剪切和拉伸两种破坏机制,应用RFPA软件模拟研究了断层处于不同位置及无断层条件下顺倾层状边坡的动态失稳过程,分析了断层对边坡滑移模式、稳定性以及滑坡力学成因机制的影响,阐明了断层效应。研究结果表明,元宝山露天矿东帮边坡的滑移模式及稳定性主要受F1断层和顺倾弱层控制,断层的存在与偏移导致的坡体内剪应力状态改变以及断层自身的抗剪强度是边坡滑移模式和稳定性发生变化的根本原因;边坡的滑坡力学成因类型与断层无关。研究结果可为露天矿合理滑坡防治措施的提出及剥采工程设计与施工提供参考。

As a kind of typical slope in open pit mine, the deformation failure mechanism and stability of dip bedded slope with faults is particularly complicated. According to the engineering practice of Eastern Slope in Yuanbaoshan Open Pit Mine, based on shear strength reduction theory, taking into account both tension and shear failure criterion, the dynamic failure process of the dip bedded slope when the fault locates at different positions or there is no fault studied by numerical simulation with RFPA, then the impact of the fault on the failure mode, stability and landslide mechanical cause of the slope are analyzed and the fault effects are demonstrated. It is shown that the failure mode and the stability of the slope are controlled by fault F1 and the dip bedded weak layer, the change of shearing stress state caused by the existence, shift of the fault and its strength are the root cause that the failure mode and the stability of the slope change and the landslide mechanical cause is irrelevant to the fault, which can provide some references for landslide prevention and the engineering design and construction in Yuanbaoshan Open Pit Min;