摘要
针对目前煤系地层隧道石门揭煤爆破掏槽技术最优参数确定复杂的难题,以西藏拉泽公路圭嘎拉隧道为研究对象,采用理论分析确定该隧道石门揭煤断面掏槽形式采用中空孔直眼掏槽,并分析了其中空孔的三种空孔力学效应;采用数值模拟试验方法建立了隧道石门揭煤直眼掏槽计算模型,从石门揭煤掏槽效率、揭煤深度和煤层动力响应等方面对不同掏槽参数展开分析。结果表明:随着掏槽关键参数a=24 cm增加到a=32 cm时,槽腔岩石破碎程度降低,煤体破碎程度相当,炮孔与空孔间未贯通的岩石厚度增加,降低了掏槽效率;a=28 cm时,局部揭煤深度过大,增大了突出风险;a=32 cm时,煤体深部出现松动区,使深部煤体应力强度降低,不同a对大断面煤系地层隧道石门揭煤煤层顶板动力作用影响较小。并获得了该煤系地层隧道石门揭煤爆破中空孔直眼掏槽掏关键参数最优值,其中炮孔与空孔间距建议值为24 cm、空孔半径建议值为100 mm;最后完成了现场爆破试验,爆破后岩体破碎程度均匀,掏槽效果好,揭煤深度适宜,其测试结果与理论研究成果较接近,验证了研究成果的可靠性。
In view of the complicated problem of determining the optimal parameters of cross-cut coal blasting cutting technology in coal-measure strata tunnels,taking the Guigala Tunnel of Tibet′s Laze Highway as the research object,theoretical analysis is used to determine that the cross-cut coal cutting section of the tunnel adopts hollow holes.Straight-cut,and analyzed the three kinds of hollow mechanical effects of the hollow holes;The numerical simulation test method is used to establish the calculation model of straight hole cut in stone gate tunnel,and different cut parameters were analyzed from the aspects of cut efficiency,cut depth and dynamic response of coal seam.The results show that with the increase of the key parameter of cutting a=24 cm to a=32 cm,the rock fragmentation degree of the trough cavity decreases,the coal body fragmentation degree is equivalent,and the thickness of the rock that is not penetrated between the blast hole and the hollow hole increases,which reduces the efficiency of cutting;When a=28 cm,the local coal uncovering depth is too large,which increases the risk of outburst;when a=32 cm,there is a loose zone in the deep part of the coal body,which reduces the stress intensity of the deep coal body.Different a has little influence on the dynamic action of the roof of the large section coal measure strata tunnel.The optimal value of the key parameters of the hollow-hole straight-hole cutting in the cross-cut coal blasting of the coal-measure formation tunnel was obtained.The recommended value of the distance between the blast hole and the empty hole is 24 cm,and the recommended value of the hole radius is 100 mm.Finally,the on-site blasting was completed.The test shows that the rock mass is uniformly broken after blasting,the cutting effect is good,and the coal uncovering depth is appropriate.The test results are close to the theoretical research results,which verify the reliability of the research results.
作者
江俐敏
吴育谦
刘存福
周圣国
王智德
JIANG Li-min;WU Yu-qian;LIU Cun-fu;ZHOU Sheng-guo;WANG Zhi-de(Architecture Engineering of Wuhan Polytechnic,Wuhan 430074,China;Nanyue Transportation Investment&Construction Co.,Ltd.,Huaiji-Yangjianggang Expressway,Guangzhou 510100,China;School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China)
出处
《爆破》
CSCD
北大核心
2022年第1期51-60,共10页
Blasting
基金
国家自然科学基金项目(编号51779197)
武汉市城乡建设委员会科技计划项目(武城建[2017]12号—201740、武城建[2019]68号—201941)
武汉职业技术学院2021年校级教科研课题(2021YK016)。
关键词
煤系地层隧道
大断面
石门揭煤爆破
中空孔直眼掏槽
优化设计
coal-bearing strata tunnel
big section
cross-cut uncovering coal blasting
central hollow hole cut
optimal design
