厚硬基本顶切顶卸压成巷及围岩控制技术  

Self-forming roadway of roof cutting and surrounding rock control technology under thick and hard basic roof

作　　者：郭金刚[1,2] 李耀晖 石松豪 蒋再胜 陈冬冬 何富连[1] 谢生荣[1] GUO Jingang;LI Yaohui;SHI Songhao;JIANG Zaisheng;CHEN Dongdong;HE Fulian;XIE Shengrong(School of Energy and Mining Engineering,China University of Mining&Technology-Beijing,Beijing 100083,China;Jinneng Holding Group Co.Ltd.,Datong 037003,China)

机构地区：[1]中国矿业大学(北京)能源与矿业学院,北京100083 [2]晋能控股集团,山西大同037003

出　　处：《煤炭学报》2021年第9期2853-2864,共12页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51974317,52074296,52004286)。

摘　　要：预裂切顶是无煤柱自成巷技术的关键,其效果直接关系到留巷的稳定性,而厚硬基本顶条件下切顶留巷的矿压现象、覆岩运移规律及控制技术又有其特殊性。以某矿切顶留巷为工程背景,综合运用UDEC数值模拟、物理相似模拟、理论分析计算及现场工业化试验等方法系统开展厚硬基本顶情况下切顶卸压成巷及围岩控制技术研究。首先,利用UDEC数值模拟软件,对比分析不同切顶高度下留巷围岩应力及位移分布规律,结果表明:切顶高度为7 m时,采空侧顶板无法沿切顶线断裂,导致留巷顶板出现下沉离层现象;切顶高度为9 m时,基本顶沿切缝线垮落,煤壁上方基本顶内应力由25~30 MPa降至20~25 MPa;再增加切顶高度对应力分布影响甚微。其次,通过物理相似模拟实验,对比分析不同切顶高度下留巷覆岩运移及矿压变化规律,结果表明:切顶高度为7 m时,基本顶断裂线位于实体煤帮侧,巷道围岩将受到断裂岩块的挤压破坏作用,从而导致巷道顶板破碎、离层、倾斜,甚至直接顶与基本顶大面积垮塌;切顶高度为9 m时,基本顶沿切缝线断裂,采空区顶板垮落时不会对巷道围岩产生挤压影响,卸压效果明显;随着切顶高度增加,切顶高度达到12 m时,基本顶沿着切缝线断裂,但是卸压幅度变化不大。再次,通过理论分析计算,确定现场工业化试验所需的预裂切缝关键参数。现场试验表明:对于厚硬顶板,孔底装药量对爆破效果影响十分显著,装药量在1.0 kg/m时可以克服孔底阻力,达到良好预裂效果;切顶高度为7 m时,巷道试验段中的单体柱出现上部被压弯变形,下部陷入底板的现象,巷道顶板向采空区侧倾斜,切缝侧顶板下沉量为450~500 mm;切顶高度为9和12 m时,巷道试验段中切缝侧顶板下沉量小,且未发现支柱损坏等现象,切顶效果良好。最后,基于上述研究,兼顾现场地质生产条件及技术经济综合考量,确定�Roof presplitting is the key to the non-pillar mining technology with automatically formed roadway,and its effect is directly related to the stability of gob-side entry retaining.Under the condition of thick and hard basic roof,the underground pressure phenomenon,the law of overlying strata migration and the control technology of gob-side entry retaining by roof cutting have their particularities.Based on the engineering background of gob-side entry retaining by roof cutting in a coal mine,through the UDEC numerical simulation,physical similarity simulation,theoretical analysis,and on-site industrialization test,the research on the technology of cutting roof and pressure relief and surrounding rock control technology under the condition of thick and hard basic roof is carried out.Firstly,by using the UDEC numerical simulation software to compare and analyze the stress and displacement distribution law of the surrounding rock of the retained roadway under different roof cutting heights.The numerical simulation results show that when roof cutting height is 7 m,the roof on the goaf side cannot be broken along the roof cutting line,which causes the roadway roof to sink and separate.When the roof cutting height is 9 m,the basic roof collapses along the cutting seam line,and the basic roof internal stress above the coal wall decreases from 25-30 MPa to 20-25 MPa.When the cutting roof height increases again,it has little effect on the stress distribution.Secondly,the laws of overlying strata migration and mine pressure changes under different cutting heights are compared and analyzed by physical similar simulation experiment.The results show that when the roof cutting height is 7 m,the basic roof fracture line is located on the solid coal side,and the surrounding rock of the roadway will be squeezed and destroyed by the fractured rock block,which lead to the roadway roof to be broken,separated,tilted,or even large area collapse of immediate roof and basic roof.When the roof cutting height is 9 m,the basic roof is broken

关 键 词：切顶卸压 围岩控制 厚硬基本顶 沿空留巷 UDEC 

分 类 号：TD322[矿业工程—矿井建设]