超前预掘留巷开采与常规留巷开采巷道破坏特征对比及成因分析  

Comparison and cause analysis of roadway failure characteristics between gob-side entry retaining with roadway advance excavation and general gob-side entry retained method

作　　者：王卫军 范磊 马谕杰 袁超 WANG Weijun;FAN Lei;MA Yujie;YUAN Chao(School of Resource,Environment and Safety Engineering,Hunan University of Science and Technology,Xiangtan,Hunan 411201,China)

机构地区：[1]湖南科技大学资源环境与安全工程学院,湖南湘潭411201

出　　处：《采矿与安全工程学报》2023年第6期1129-1138,共10页Journal of Mining & Safety Engineering

基　　金：国家自然科学基金项目(52074115);湖南省自然科学基金青年基金项目(2021JJ40211);湖南省教育厅优秀青年基金项目(21B0486)。

摘　　要：沿空留巷作为无煤柱开采技术的一种,在提高煤炭回收率、降低开拓掘进量的同时,也给后续留巷巷道的维护带来诸多挑战。以沿空留巷技术的应用为主线,选取Y型通风的后退式留巷工艺(常规留巷工艺)和超前预掘运输巷的前进式留巷工艺(超前预掘留巷工艺)为研究对象,研究2种不同留巷工艺下回采巷道的破坏特征,通过分析回采巷道三维应力场的演化规律,揭示不同留巷工艺下回采巷道差异破坏的力学机理。结果显示,围岩主应力方向的分布与开挖空间的形成密切相关,在开挖空间附近的“应力扰动区”内,岩体的最小主应力总是近似指向开挖空间的几何中心,最大主应力呈椭球形将开挖空间环向包裹;不同留巷工艺下回采巷道围岩应力场的分布规律也不尽相同,巷道主应力的大小和侧压系数的高低在一定程度上共同决定了巷道的破坏形态;采动应力对回采巷道的影响并不总是不利的。应力场是矢量场,具有大小和方向,回采巷道的破坏特征取决于采动应力和原岩应力矢量相加所形成的“复合应力场”,而不是两场的代数和。因此,开拓方式的选取和支护参数的确定不仅要考虑原岩应力场的分布规律,还需要考虑采动应力场的影响。在一定条件下,合理利用采动应力可以改善围岩的应力环境,降低回采巷道维护难度。As a kind of non-pillar coal mining technology,gob-side entry retaining not only improves the coal recovery rate and reduces the amount of mine development and excavation,but also brings many challenges to the maintenance of the gob-side entry.Taking the application of gob-side entry retaining technology as the main line,the gob-side entry retaining with backward coal mining method of Y-shaped ventilation(general gob-side entry retained method)and the gob-side entry retaining with advance excavate transport roadway(gob-side entry retaining with roadway advance pre-excavation)are selected as the research.The failure characteristics of the mining roadway under two different roadway retaining techniques were studied.By analyzing the evolution law of the three-dimensional stress field of the mining roadway,the mechanical mechanism of the differential failure of the mining roadway under different roadway retaining techniques is revealed.The results show that:The distribution of the principal stress direction of the surrounding rock is closely related to the formation of the excavation space.In the"stress disturbance zone"near the excavation space,the minimum principal stress of the rock mass always approximately points to the geometric center of the excavation space,and the maximum principal stress forms an ellipsoid to encircle the excavation space.The distribution law of the surrounding rock stress field of the mining roadway under different entry retaining techniques is also different.The size of the principal stress and the lateral pressure coefficient of the roadway jointly determine the failure form of the roadway to a certain extent;The influence of mining stress on the mining roadway is not always unfavorable.Stress fields are vector fields with magnitude and direction.The failure characteristics of the mining roadway depend on the"composite stress field"formed by the vector addition of the mining-induced stress and the in-situ rock stress,rather than the algebraic sum of the two stress fields.Therefore,the se

关 键 词：超前预掘 沿空留巷 塑性区 差异破坏 

分 类 号：TD323[矿业工程—矿井建设]