孤岛煤柱下底板岩体损伤过程与分区破坏特征分析  

Analysis of damage process and zonal failure characteristics of rock mass under floor of isolated coal pillar

作　　者：赵洪宝[1] 刘一洪 李金雨 徐建峰 ZHAO Hongbao;LIU Yihong;LI Jinyu;XU Jianfeng(School of Energy and Mining Engineering»China University of Mining and Technology(Beijing),Beijing 100083,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083

出　　处：《中国矿业大学学报》2021年第5期963-974,共12页Journal of China University of Mining & Technology

基　　金：越崎杰出学者资助项目(800015Z1179);国家自然科学基金项目(51474220);中央基本科研业务费项目(2009QZ03)。

摘　　要：以回坡底煤矿为工程背景,分别建立了工作面前方支承压力扰动阶段和采空区压实稳定阶段的底板力学模型.基于相关力学模型,通过理论计算分别得到了支承压力扰动阶段、底板卸压阶段和采空区压实稳定阶段的底板岩体破坏特征.计算结果表明:在工作面前方支承压力扰动阶段,仅在工作面外侧底板岩体发生了破坏;在底板卸压阶段,工作面底板岩体发生了卸荷破坏,破坏形态呈半弧形,最大卸荷破坏深度约26 m,位于工作面底板中部;在采空区压实稳定阶段,残留煤柱下方岩体的主应力差增大,发生了较为严重的压剪破坏.由理论计算结果得到了采场底板岩体的分区破坏特征,并采用数值模拟手段对采场底板分区破坏特征进行了验证,数值模拟结果与理论计算结果大致相当,基于底板岩体的分区破坏特征对下层煤回采巷道的非对称变形机制进行了初步分析.以卸荷时间间接表征工作面推进速度,推导得出了考虑岩体卸荷应力及工作面推进速度的蠕变本构方程,计算结果表明:适当提高工作面推进速度可提高底板岩体的稳定性和完整性.Taking the Huipodi coal mine as the engineering background, the mechanical model of the floor of the abutment pressure disturbance stage in front of the working face and the compaction stability stage of the goaf were respectively established. Based on the relevant mechanical model, the damage characteristics of the floor in the stage of abutment pressure disturbances stage, the floor pressure relief and the goaf compaction stability were obtained by theoretical calculation. The calculation results show that in the stage of abutment pressure disturbance, only the shearing damage occurred in the floor outside the working face. During the pressure relief stage of the floor, unloading failure occurred on the floor of the working face, and the failure mode is semi-arc. The maximum unloading damage depth is about 26 m, which is located in the middle of the floor of the working surface. During the compaction and stabilization phase of the goaf, the principal stress difference of the floor of the residual coal pillar increased, and serious compression-shear failure occurred. Based on the theoretical calculation results, the partition failure characteristics of the stope floor were obtained, and numerical simulation was used to verify the partition failure characteristics of the stope floor. The numerical simulation results are roughly equivalent to the theoretical calculation results. Based on the regional failure characteristics of the floor, the asymmetric deformation mechanism of the floor roadway was analyzed. The unloading time was used to indirectly characterize the propulsion speed of the working face. The creep constitutive equation considering the unloading stress and the working surface advancing speed was derived. The calculation results show that the proper improvement of the working surface advancement speed can improve the stability and integrity of the floor rock mass.

关 键 词：底板 卸荷破坏 分区破坏 非对称变形 蠕变本构 

分 类 号：TD323[矿业工程—矿井建设]