基于顶板水力压裂卸压的应力场响应机制研究及应用  

Research and application of stress field response mechanism based on roof hydraulic fracturing pressure relief

作　　者：程利兴 张镇 姜鹏飞[1,2,3] 杨建威[1,2,3] CHENG Lixingg;ZHANG Zhen;JIANG Pengfei;YANG Jianwei(CCTEG Coal Mining Research Institute,Beijing 100013,China;Coal Mining and Designing Department,Tiandi Science and Technology Co Ltd,Beijing 100013,China;Coal Mining and Designing Branch,China Coal Research Institute,Beijing 100013,China)

机构地区：[1]中煤科工开采研究院有限公司,北京100013 [2]天地科技股份有限公司开采设计事业部,北京100013 [3]煤炭科学研究总院开采研究分院,北京100013

出　　处：《采矿与安全工程学报》2023年第4期722-729,共8页Journal of Mining & Safety Engineering

基　　金：国家重点研发计划项目(2017YFC0603003);天地科技股份有限公司开采设计事业部重点基金项目(KJ-2022-KCZD-01)。

摘　　要：针对深井高应力强采动巷道的支护难题,分析顶板水力压裂技术原理,建立巷道围岩水力压裂数值计算模型,开展水力压裂切顶卸压应力转移研究,分析巷道围岩应力场响应机制,并开展现场工程应用。结果表明:水力压裂后煤柱应力集中区应力降低率为7.73%,平均降幅为13.9 MPa,最大降幅为24.9 MPa,采空区应力增长率为3.75%,在采空区应力增长区内,顶板压裂后底板应力较无压裂时平均高出约6.4 MPa,有效弱化了坚硬悬顶,阻断了顶板岩层的应力传递,促使煤柱侧悬顶应力向采空区内转移;水力压裂后工作面周期来压步距和液压支架动载系数显著降低,煤柱应力趋于均匀化,且平均应力显著低于无压裂时的煤柱应力,超前采动影响时矿压显现强度得到有效降低;压裂段滞后工作面30 m范围内采空区顶板及时垮落,应力增长较快,滞后工作面距离大于30 m时,压裂段采空区应力基本呈缓慢增长,最大应力值为1.35 MPa,无压裂段采空区应力且仍呈快速增长趋势,最大应力值为1.64 MPa。这表明水力压裂可有效弱化坚硬顶板完整性,改善采空区覆岩结构运动状态,降低巷道围岩应力状态,提高巷道围岩的稳定性。Aiming at the solving support problem of high stress and strong mining roadway in deep mine,the principle of hydraulic fracturing weakening hard roof is analyzed,the numerical calculation model of hydraulic fracturing of roadway surrounding rock is established,the stress transfer research of hydraulic fracturing roof cuting and pressure relief is carried out,the response mechanism of roadway surrounding rock stress field is analyzed,and the field engineering application is carried out.The results show that the stress reduction rate is 7.73%in the stress concentration area of coal pillar after hydraulic fracturing,with the decrease of 13.9 MPa on average.The maximum decrease is 24.9 MPa,and the stress growth rate of goaf is 3.75%.In the stress growth area of goaf,the floor stress after roof fracturing is about 6.4 MPa higher than that without fracturing on average,which effectively weakens the hard suspended roof,blocks the stress transmission path of roof rock,and promotes the stress transfer of coal pillar side suspended roof to the goaf;The periodic pressure step distance of the working face and the dynamic load coefficient of the hydraulic support are significantly reduced after hydraulic fracturing,stress of the coal pillar tends to homogenize,and the average stress is significantly lower than the coal pillar's stress without fracturing;additionally,under the influence of advance mining,the intensity of the ground pressure appearance is significantly reduced.The roof of the goaf in the fracturing section within 30 m of the lagging working face collapses in time,and the stress increases rapidly.When the lagging working face distance is longer than 30 m,the stress in the goaf in the fracturing section increases slowly,with the maximum stress of 1.35 MPa.The stress in the goaf without fracturing still shows a rapid growth trend,with a maximum stress value of 1.64 MPa.Therefore,it can be calculated that hydraulic fracturing can effectively weaken the integrity of hard roof,improve the movement state of overburden

关 键 词：千米深井 顶板预裂 应力转移 卸压机理 

分 类 号：TD353[矿业工程—矿井建设]