采空区对地下开采与露天开采转换过程中的边坡稳定性存在一定的影响。为了研究空区对边坡稳定性的影响规律,利用强度折减法分析多种情况下边坡的稳定性。研究结果表明:空区在坡脚附近,边坡的安全系数降低达20%左右;边坡中部的空区对边坡的稳定性影响取决于空区几何中心相对于滑动面水平位置,空区几何中心在滑动带内将引起边坡稳定性增加,空区几何中心在滑动带外将引起边坡稳定性减小;空区在边坡脚下部时,在距边坡脚水平距离一定范围内,空区会引起滑坡体体积增大,边坡安全系数降低;在距边坡脚水平距离某一范围内的空区,由于自身顶板松动区的出现导致边坡体的下滑力降低,使边坡的安全系数增加;同一高度的空区,距坡面水平距离的不同会引起边坡滑动面位置发生改变;空区几何中心距离滑动面超过一定距离后,边坡的稳定性不再受空区的影响。该规律对地下开采与露天开采转换过程中的边坡工程施工具有一定的实践指导意义。
The goaf has greatly influence on the slope stability.The goaf with different span and position has different influences on the slope stability.The stability of slope with different goafs was analysed.The results show that the safety factor reduces by 20% when the goaf lies in the bottom of the slope.When the goaf lies in the middle of the slope,the influence on the slope stability depends on the relative horizontal position of the goaf geometric center and the slipping face.When the geometric center of the goaf lies in the interior of the slids,the slope stability is enhanced.When the goaf center lies in the outside of the slids,the slope stability decreases.The safety factor of the slope is greatly influenced when the goaf lies in the bottom of the slope.The goaf may make the slip zone thicker when the goaf lies near the sliding surface.At the same time the stability of slope reduces to some extent.The slope stability increases when the broken zone of the goaf roof causes the sliding force to decrease.The effect of goaf is weakened when the distance between the the geometric center of the goaf and slids face exceeds a limit.This law has guidance to the slope excavation engineering practice in open-pit mining transferring.