含顺倾弱层软岩边坡三维稳定性影响因素分析

Analysis on Three Dimensional Stability Influence Factors of Soft Rock Slope with Dip Weak Layer

为定量揭示露天矿开挖过程中各人为因素对含顺倾弱层软岩边坡三维稳定性的影响及其程度,以扎哈淖尔露天矿南帮边坡为工程背景,基于强度折减法,应用FLAC^(3D)数值模拟软件,探讨了开挖位置、开挖坡角和内排追踪距离不同时南帮边坡的变形破坏机制和边坡稳定性的影响规律。结果表明:无论开挖位置、开挖坡角与追踪距离如何变化,横采南帮的滑坡模式均为以IVC煤底板弱层为底界面的切层-顺层滑动;在横采条件下,边坡三维稳定性主要受内排追踪距离影响,随追踪距离的增大呈负指数规律减小,且随开挖位置的向南偏移或开挖坡角的减小近线性减小;在横采条件下,内排土场与工作帮间的追踪距离控制在一定范围内时,可以充分利用边坡稳定性的三维效应回收煤炭资源。

In order to quantitatively reveal the influence and its degree of the human factors on the three-dimensional sta- bility of the soft rock slope with dip weak layer in the open-pit mining process, with the south slope of Zahanaoer Open-pit Mine as engineering background,and based on the strength reduction method, FLAC3D numerical simulation software is adopted to discuss the influences law of the excavation position, the excavation angle and the inner dumping distance to deformation failure mechanism and slope stability of the south slope. Results show ： No matter how the excavation position, the excavation angle and the inner dumping distance change, the landslide model of horizontal mining south slope is cutting-bedding slide with the IVC coal seam weak layer as the bottom; Under the condition of horizontal mining, the slope three-dimensional stability is mainly affected by inner dumping distance, which decreases with the increase of dumping distance in negative exponent law, and line- arly decreases with excavation position southward offset or decrease of excavation angle. Under the condition of horizontal min- ing, the track distance between the inner dump and the working group should be controlled within a certain range, can effective- ly utilize the three-dimensional effect of slope stability to recover the coal resources.