多因素耦合下的采空区上覆岩层安全厚度分析

Research on Safety Thickness of Overlying Strata in Goaf Under Multi-factor Coupling

为了研究露天矿多因素耦合下的采空区上覆岩层安全厚度变化规律,针对河曲露天矿已探明采空区进行了顶板安全厚度分析;建立采空区及周边岩体的数值模型,分析不同跨度的采空区在震动载荷因素和双采空区叠加影响下顶板沉降位移变化规律。结果表明:采空区上覆岩层安全厚度随采空区跨度的增加而增大,且采空区跨度达到60 m时,上部岩层发生严重破坏;考虑震动荷载时,随着采空区跨度的增大,震动荷载的影响越为明显;双采空区产生叠加影响的采空区间距范围为40 m以内。综合采空区上覆岩层安全厚度的理论分析与数值模拟结果,给出河曲露天矿开采范围内的采空区处置方案。

In order to study the variation rule of the safe thickness of overlying strata under multi-factor coupling,the safe thickness of roof was analyzed for the proved goaf in Hequ Open-pit Mine.Numerical model of mined-out area and the surrounding rock mass is established,the change laws of different spans mined-out area under shock load factor and double superposition of goaf roof subsidence displacement are analyzed.The results showed that the mined-out area overburden safety thickness increases with the increase of the span mined-out area,and when the span of goaf reaches 60 m,the upper strata will be seriously damaged;the influence of vibration load becomes more obvious with the increase of goaf span considering vibration load.The spacing range of goaf with superimposed influence is within 40 m.Based on the theoretical analysis and numerical simulation results of safety thickness of overlying strata in goaf,the disposal plan of goaf in Hequ Open-pit Mine is given.