摘要
针对永城市薛湖煤矿局部聚能爆注效果差及未确定局部聚能爆注卸压的影响范围,不能在工作面合理布置聚能爆注孔间距的难题,通过理论分析、ANSYS/LSDYNA数值模拟及工业性试验,设计一种局部水环保压装置,对薛湖煤矿局部水环保压下聚能爆注卸压进行研究与应用,结果表明:(1)通过ANSYS/LSDYNA发现,水的低压缩性能够聚集炸药爆炸的能量,煤体损伤范围显著增大,水介质耦合时煤体完全损伤范围为空气耦合时的3.14倍;水介质耦合时煤体损伤裂纹长度范围为空气耦合时的2.71倍。水介质使聚能炸药能量均匀作用在煤体上,减弱聚能管的定向作用,钻孔周围裂隙均匀发育扩展,无定向裂隙扩展,通过在水介质和钻孔壁间设置聚能管能够有效聚能和定向扩展裂隙。当炸药处于钻孔、水体中心时,煤体裂隙扩展、爆注空腔面积均优于炸药处于钻孔、水体下部时。(2)水环保压装置使炸药始终处于钻孔、水体中心,环向约束炸药,减少炸药爆炸径向能量损失,增强炸药作用于煤体上的能量。水环保压装置内部设置聚能槽,使得存水保压、聚能一体化,起到有效的聚能定向卸压作用。(3)通过工业性试验对比聚能爆注前后钻孔内的瓦斯参数变化,得出薛湖煤矿局部水环保压下聚能爆注影响半径为2.5 m;在薛湖煤矿工作面以钻孔间距5 m布置局部水环保压聚能爆注孔,煤体局部裂隙扩展,集中应力得到转移与释放。通过爆注后的水环保压装置向煤层中注水,使得爆注孔变为煤层注水孔,可以进一步浸润煤体,改变煤体性质,改善工作面环境。由于水环保压聚能爆注技术存在爆破空腔面积大、定向聚能扩展裂隙及注水改变围岩性质的优势,可将此技术用于切割顶板,强制放顶。
Due to the poor effect of local energy-accumulation blasting and water injection in the Xuehu Coal Mine and the undetermined influence range of local energy-accumulation blasting and water injection pressure relief,the spacing of blasting holes cannot be reasonably arranged in heading face.Through theoretical analysis,ANSYS/LSDYNA numericalsimulation and industrial experiments,designing a local water storage and pressure retention device,this study investig-ated the application of energy-accumulation blasting and water injecting under local water storage and pressure retention in the Xuehu Coal Mine.The results showed:①the ANSYS/LSDYNA simulation reveals that the low compressibility of water can accumulate explosive energy,resulting a significant increase of coal damage range.Complete damage range of coal mass in the water medium coupling is 3.14 times of that in the air medium coupling,the range of damage crack length of coal mass in the water medium coupling is 2.71 times of that in the air medium coupling.Water medium makes the en-ergy of energy-accumulation explosive uniformly act on coal,then weakens the directional effect of the energy-accumula-tion pipe,and uniforms the development and extension of cracks around borehole.Effective energy accumulation and dir-ectional propagation of fractures can be achieved by installing energy-accumulation pipe between water medium and bore-hole walls.When the explosive is in the center of the borehole and the water body,the crack propagation and the blasting cavity area are better than that when the explosive is in the lower part of the borehole and the water body.②The water storage and pressure retention device makes the explosive always in the center of borehole and water body,restricts the ex-plosive circumferentially,reduces the radial energy loss of explosive explosion,and enhances the energy of explosive act-ing on coal body.The energy-gathered pipe set inside water storage and pressure retention device integrates water storage,pressure retention and energy accumulation,and plays an effective directional role.③The change of gas parameters in borehole before and after energy-accumulation blasting and water injecting is compared by industrial experiments,and the influence radius of blasting is 2.5 m.The local concentrated stress is transferred and released when the energy-accumula-tion blasting and water injecting holes are arranged with 5 m spacing in the Xuehu Coal Mine.By injecting water into the coal seam through the water storage and pressure retention device after blasting,the blasting and water injection holes are changed into the coal seam water injection holes,which can further moisten the coal body,change the nature of the coal body and improve the heading face environment.Due to the advantages of large blasting cavity area,directional energy-gathering expansion cracks and water injection to change the properties of surrounding rock,this technology can be used to cut the roof and forced roof caving.
作者
王振锋
王宇
张涛
WANG Zhenfeng;WANG Yu;ZHANG Tao(School of Energy Science and Engineering,Henan Polytechnic University,Jiaozuo454003,China;Collaborative Innovation Center of Coal Work Safety,Jiaozuo 454003,China;Xuchang Xinlong Mining Co.,Ltd.,Shenhuo Group,Xuchang 452570,China)
出处
《煤炭学报》
EI
CAS
CSCD
北大核心
2023年第11期4036-4048,共13页
Journal of China Coal Society
基金
国家自然科学基金资助项目(41872188)。
关键词
局部聚能爆注
增透卸压
水环保压装置
瓦斯参数
影响半径
energy-accumulating blasting and water injection
increased permeability and pressure relief
water stor-age and pressure keeping device
gas parameters
influence radius
