基于简单梁计算方法的煤矿采空区覆岩移动变形分析探讨

Analysis and Discussion on Movement Deformation of Overburden Rock above Goaf in Coal Mine Based on Calculation Method of Simple Beam

煤矿采空区覆岩移动与裂隙演化特征直接影响采空区场地稳定性。通过将裂隙椭抛带理论引入简单梁计算模型来确定岩层移动性状,并结合UDEC数值模拟,对覆岩移动与离层裂隙演化特征进行验证性描述。结果表明:简单梁计算模型与关键层理论具有一致性,岩层下沉整体表现为抛物线型。岩层移动过程中,伴随着裂隙椭抛带的形成,离层裂隙形态在岩层破断垮落前,表现为抛物线型;垮落后,转变为马鞍型。理论分析与研究成果可为采空区治理设计与施工提供理论参考。

The movement and cracking evolution features of the overburden rock in the goaf of the underground mine would directly affect the stability of the site ground in the goaf.The elliptical throwing zone theory of the cracking to the simple beam calculation model could be introduced to determine the movement condition of the rock strata.In combination with the UDEC numerical simulation,the qualitative description on the overburden rock movement and the cracking evolution features of the bed separation could be conducted.The results showed that the simple beam calculation model and the key strata theory would have the consistency and the rock strata subsidence would wholly be in a parabolic model.During the movement processing of the rock strata,with the formation of the cracking elliptical throwing zone,the cracking condition of the separation bed would be in the parabolic model before the breaking and collapsing.After the collapse,the cracking condition of the separation bed would be turned in a saddle shaped.The theoretical analysis and study results could provide the theoretical references to the control design and construction of the goaf.