不同切顶角度下临空巷道围岩力学响应特征及控制效果  

Mechanical Response Characteristics and Control Effect of Surrounding Rock of Gob-side Roadways under Different Roof Cutting Angles

作　　者：聂嘉汾 张海东 NIE Jiafen;ZHANG Haidong(Taiyuan Coal Gasification(Group)Co.,Ltd.,Taiyuan 030006,China;Shanxi Institute of Technology,Yangquan 045000,China)

机构地区：[1]太原煤炭气化(集团)有限责任公司,太原030006 [2]山西工程技术学院,山西阳泉045000

出　　处：《山西煤炭》2024年第4期120-127,共8页Shanxi Coal

摘　　要：顶板岩层邻近采空区侧形成的长跨度侧向悬顶,是综采工作面临空巷道大变形的根本原因。基于山西李庄煤矿8105工作面回风顺槽巷道变形问题,通过理论分析,揭示了临空巷道变形机理,提出采用水力压裂切顶卸压方法;结合数值模拟,分析了不切顶以及切顶角度在0°、10°、20°、30°、40°条件下临空巷道围岩的力学响应特征,并对各切顶角度下的卸压效果进行对比。结果表明:切顶后顶板岩层支承应力传递路径被阻断,巷道围岩应力得到改善,随着切顶角度的增加,护巷煤柱巷道侧垂直应力先降低后增加,在20°切顶角度下煤柱巷道侧垂直应力最小,在30°以后顶板岩层支承应力传递路径被再次激活而连通,导致支承压力再度增加;随着切顶角度增大,巷道围岩变形呈先降低后增大规律,20°和30°切顶角度下煤柱水平位移与垂直位移均不超过0.02 m;经卸压效果对比,确定采用切顶高度30 m、切顶角度20°的水力压裂切顶卸压方法。研究成果可为该巷道围岩控制提供理论指导。The long-span lateral suspended roof formed adjacent to the goaf of the roof strata is the fundamental cause for the large deformation of the gob-side entry in the fully mechanized mining face.Lijiayao Coal Industry Co.,Ltd.Based on the deformation of the return airway in the No.8105 working face of Lizhuang Mine,we revealed the deformation mechanism of the gob-side entry with theoretical analysis and proposed hydraulic fracturing and roof cutting to relieve pressure.With numerical simulation,the mechanical response characteristics of the surrounding rock were analyzed under various conditions,including no roof cutting and roof cutting angles of 0°,10°,20°,30°,and 40°,and the pressure relief effects at the roof cutting angles were compared.The results showed that after roof cutting,the transmission path of the supporting stress of the roof strata was blocked,and the stress in the surrounding rocks of the roadway was improved.With the increase of the roof cutting angle,the vertical stress on the roadway side of the coal pillar decreased and then increased:the vertical stress was minimal at a roof cutting angle of 20°,and after 30°,the transmission path of the supporting stress of the roof strata was reactivated and connected,leading to an increase in supporting pressure.As the roof cutting angle increased,the deformation of the surrounding rocks decreased and then increased.The horizontal and vertical displacement of the coal pillars at roof cutting angles of 20°and 30°did not exceed 0.02 m.After comparing the pressure relief effects,it was determined to adopt the hydraulic fracturing roof cutting and pressure relief method with a roof cutting height of 30 m and a roof cutting angle of 20°.The research results could provide theoretical guidance for the surrounding rock control of the roadway.

关 键 词：临空巷道 侧向悬顶 水力压裂 切顶角度 应力演化 

分 类 号：TD322[矿业工程—矿井建设]