断层位置对露天矿顺倾层状边坡稳定性的影响研究

Influence of fault's position on stability of dip bedded slope in surface mines

为分析断层位置对露天矿顺倾层状边坡稳定性的影响,基于极限平衡理论,建立断层作用下滑体的力学模型,推导出顺倾层状边坡分条稳定系数表达式。以元宝山露天矿为工程背景,应用FLAC3D软件模拟研究F1断层处于不同位置时东帮顺倾层状边坡的滑移模式及稳定性变化规律。结果表明,当弱层倾角β和断层倾角δ满足β+δ≤90°时,边坡稳定性随着断层向边坡内侧偏移而增大,直至偏移到某一位置时,稳定系数与不含断层边坡相等且不再增大;该矿东帮边坡稳定性主要受4号弱层控制,F1断层次之;当F1断层露头与边坡面的水平距离小于168 m时,断层向边坡内侧偏移将使边坡稳定性近线性增大;当距离达到198 m时,F1断层对边坡滑移模式与稳定性的影响效应消失。

To analyze impacts of fault location on the slope of dip bedded slope in surface mines, based on limit equilibrium principle, mechanical models of sliding body containing a fault were built, then stability factor expressions were worked out. With Yuanbaoshan surface mine as the engineering background, effects of position of fault F1 on sliding mode and stability of eastern dip bedded slope were studied by numerical simulation with FLAC^3D. It is shown that when the summation of fault angle （δ） and weaken layer angle （β） is less than 90°, the stability of dip bedded slope must increase with fault shifting inside until arriving at a point where stability ceases to increase and accords that of a slope with the same properties but without fault, that stability of eastern slope in Yuanbaoshan surface mine is primarily controlled by 4^th weak layer and by the fault secondly, that slope stability must increase with shift of fault inside when the horizontal distance between fault outcrops and the slope surface is less than 168 m, and that effect of fault F1 on slope sliding mode and stability will disappears when the distance reaches 198 m.