定向水力致裂对煤层顶板三向应力的影响研究  

Influence of directional hydraulic fracture on three-dimensional stress of coal seam roof

作　　者：高厚 陈卫忠[1,3] 邢天海[4] 郑有雷[4] 贾晓东[4] 程文武[4] GAO Hou;CHEN Wei-zhong;XING Tian-hai;ZHENG You-lei;JIA Xiao-dong;CHENG Wen-wu(State Key Laboratory of Geomechanics and Geotechnical Engineering,Institute of Rock and Soil Mechanics of Chinese Academy of Sciences,Wuhan 430071,China;University of Chinese Academy of Sciences,Beijing 100049,China;Geotechnical and Structural Engineering Research Center,Shandong University,Jinan 250061,China;Jisan Coal Mine,Yanzhou Coal Mining Co.,Ltd.,Jining 272000,China)

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,湖北武汉430071 [2]中国科学院大学,北京100049 [3]山东大学岩土与结构工程研究中心,山东济南250061 [4]兖州煤业股份有限公司济三煤矿,山东济宁272000

出　　处：《煤炭工程》2020年第3期113-117,共5页Coal Engineering

基　　金：国家重点研发计划资助项目(2018YFF01014200);国家重点基础研究发展计划(973计划)资助项目(2015CB057906)。

摘　　要：煤层顶板水力致裂是处理坚硬顶板和防治冲击地压的重要技术手段之一,为了研究水力致裂技术对煤层顶板三向应力的影响,通过现场开展煤层顶板定向水力致裂试验,采用光纤光栅三向应力传感器得到了致裂前后顶板岩层的三向应力。结果表明:水力致裂之后,监测断面处顶板岩层三个主应力均有所降低,最大降幅约为20%,而主应力方向变化很小;在工作面坐标系下,致裂部位处各应力分量的降幅受致裂面方位的影响。顶板水力致裂能够显著降低或者转移顶板岩层三向应力,对致裂部位具有良好的卸压效果。研究成果可为现场水力致裂钻孔布置提供参考,并可用于冲击地压防治研究。Hydraulic fracture of coal seam roof is one of the important means to deal with hard roof and prevent rockburst.In order to study the influence of hydraulic fracture on the three-dimensional stress of coal seam roof,a Fiber Bragg grating(FBG)sensor was adopted in the field test of directional hydraulic fracture of coal seam roof to monitor the three-dimensional stress in rock strata before and after hydraulic fracture.The results show that at the monitoring section the magnitude of three principle stress decreases after hydraulic fracture,and the biggest drop is about 20%;meanwhile the direction of three principle stress changes very little.In the working face coordinate system,the decline of every stress component at the fracture position is affected by the orientation of the fracture plane.Hydraulic fracture of coal seam roof significantly reduces or transfers the three-dimensional stress in roof strata,showing favorable pressure relief effect for fracturing position.The study can offer reference for the layout of hydraulic fracture boreholes,and the prevention and control of rockburst.

关 键 词：水力致裂 现场试验 顶板岩层 三向应力 

分 类 号：TD323[矿业工程—矿井建设]