水力压裂切顶应力空间转移机制分析  

Analysis of Stress Spatial Transfer Mechanism in Hydraulic Fracture Roof Cutting Technology

作　　者：张西锋 史发慧 王会闯 ZHANG Xifeng;SHI Fahui;WANG Huichuang(National Energy Group Shendong Coal Group,Yulin 719315,China;Changzhou Scientific Research and Trial Production Center Co.,Ltd.,Changzhou 213000,China)

机构地区：[1]国家能源集团神东煤炭集团,陕西榆林719315 [2]常州科研试制中心有限公司,江苏常州213000

出　　处：《煤炭技术》2024年第6期129-133,共5页Coal Technology

摘　　要：水力压裂切顶技术可以弱化顶板的应力传递机制,为探究水力压裂作用下覆岩应力空间的变化特征,以布尔台煤矿为例,采用理论分析对关键块弧形三角板的垮落稳定性进行表征,并运用GDEM软件对双向水力压裂护巷技术进行模拟。结果表明:工作面顶板会发生滑落回转与挤压变形失稳,应采取有效的顶板控制技术对覆岩结构进行弱化。当压裂角度为30°时,水力压裂裂缝向采空区的方向扩展充分,可以有效切断顶板阻绝应力传递。当实施水力压裂后,煤柱侧的应力降幅较为明显,同位置最大降低值为24.9 MPa,平均降低13.9 MPa。原因是在水力裂缝与采动影响产生的次生裂缝的作用下,顶板的完整性被弱化,巷道围岩的应力向采空区方向转移。Hydraulic fracture roof cutting technology can weaken the stress transfer mechanism of the roof.To explore the changing characteristics of overburden stress space under the action of hydraulic fracture,theoretical analysis is used to characterize the collapse stability of key block arc triangular slab and GDEM software is used to simulate the bi-directional hydraulic fracture roadway protection technology,taking Bultai coal mine as an example.The results show that the working face roof plate will be subject to slip slewing and extrusion deformation destabilization,and effective roof control techniques should be adopted to weaken the overlying rock structure.When the fracturing angle is 30°,the hydraulic fractures expand sufficiently in the direction of the mining area,which can effectively cut off the roof plate to block the stress transfer.When hydraulic fracturing is implemented,the stress reduction on the coal column side is more obvious,with the maximum reduction value of 24.9 MPa at the same location and an average reduction of 13.9 MPa.The reason is that the integrity of the roof is weakened under the action of the hydraulic fracture and the secondary fracture generated by the influence of mining,and the stress of the roadway surrounding rock is transferred to the direction of the goaf.

关 键 词：水力压裂 关键块 顶板垮落 数值模拟 

分 类 号：TD323[矿业工程—矿井建设] TD322.5