采动卸荷与岩层倾角对底板损伤的协同影响效应  

Synergistic effect of mining unloading and rock inclination on floor failure characteristics

作　　者：赵洪宝[1,2] 刘一洪 李金雨 刘瑞 ZHAO Hongbao;LIU Yihong;LI Jinyu;LIU Rui(School of Energy and Mining Engineering,China University of Mining and Technology(Beijing),Beijing 100083,China;State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mine,Anhui University of Science and Technology,Huainan,Anhui 232001,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083 [2]安徽理工大学深部煤矿采动响应与灾害防控国家重点实验室,安徽准南232001

出　　处：《中国矿业大学学报》2022年第6期1056-1068,共13页Journal of China University of Mining & Technology

基　　金：越崎杰出学者计划项目(800015Z1179);国家自然科学基金项目(51474220);中央高校基本科研业务费研究生科研创新能力提升项目(2020YJSNY07)。

摘　　要：以回坡底煤矿为工程背景,建立了采场底板力学模型并分析岩层倾角对底板破坏特征的影响.计算结果表明:在工作面超前支承压力扰动阶段,底板不容易发生破坏,而在采空区压实稳定阶段,底板发生较大范围的压剪破坏.底板破坏形态随着岩层倾角增加而朝下山方向倾斜,导致下山侧底板破坏程度大于上山侧底板.通过分析岩体卸荷破坏特征发现,主应力卸荷量的增加导致底板产生卸荷张拉损伤的概率增加,而最小主应力卸荷量的增加会减小底板发生卸荷滑移损伤的概率.通过分析底板主应力矢量分布特征得到了底板的卸荷应力路径,随着岩层倾角增加,上山侧底板和下山侧底板的主应力轴逐渐呈非对称分布特征,主应力轴基本平行或呈锐角相交.数值模拟结果表明:底板球应力卸压体范围随岩层倾角增加而增加,并且上山侧底板卸压体范围大于下山侧底板.采空区浅部底板以卸荷张拉破坏为主,深部底板以拉剪复合破坏为主,并且底板破坏区基本位于卸压体内.Taking Huipodi Coal Mine as the engineering background,a floor mechanics model was established and the influence of rock inclination on the failure characteristics of the floor was analyzed.The calculation results show that the floor is not easily damaged in the stage of abutment pressure disturbance,but in the stage of compaction and stability of the goaf,the floor suffers a large range of compression shear failure.The failure pattern of the floor is inclined towards the downhill direction with the increase of the rock inclination,which results in the consequence that the failure degree of the floor on the downhill side is greater than that on the other side.By analyzing the unloading damage characteristics of rock mass,it is found that the increase of the unloading amount of principal stress leads to an increase in the probability of unloading tensile damage of the floor,while the increase of the unloading amount of the minimum principal stress will reduce the probability of unloading slip damage.By analyzing the distribution characteristics of the principal stress vector of the floor,the unloading stress path of the floor is obtained.With the increase of the rock inclination,the principal stress axes on both sides of the floor gradually show asymmetric distribution characteristics,and the principal stress axes are basically parallel or intersect at an acute angle.The numerical simulation results show that the range of the relief body of the ball stress of the floor increases with the increase of the rock inclination,and the range of the relief body of the floor on the uphill side is larger than that on the other side.The shallow floor of the goaf is mainly damaged by unloading tension,and the deep floor is mainly damaged by tension-shear composite,and the floor failure area is basically located in the pressure relief body.

关 键 词：岩层倾角 卸荷破坏 分区破坏 卸荷应力路径 应力卸压体 

分 类 号：TD821[矿业工程—煤矿开采]