浅孔楔形掏槽爆破技术在特大断面小净距隧道群施工中的应用  

Application of Shallow Hole Wedge Cut Technology in Construction of Extra-Large Section and Small Clear Distance Tunnel Groups

作　　者：张满 康钦容 李梦玲 蒋富强 姜永东[3] 刘远鹏[2] 侯鹏伟 张卫中 ZHANG Man;KANG Qinrong;LI Menging;JIANG Fuqiang;JIANG Yongdong;LIU Yuanpeng;HOU Pengwei;ZHANG Weizhong(Xingfa School of Mining Engineering,Wuhan Institute of Technology,Wuhan 430074,China;China Railway Tunnel Group No.2 Engineering Co.,Ltd,Sanhe 065201,China;School of Resources and Safety Engineering,Chongqing University,Chongqing 400044,China)

机构地区：[1]武汉工程大学兴发矿业学院,湖北武汉430074 [2]中铁隧道集团二处有限公司,河北三河065201 [3]重庆大学资源与安全学院,重庆400044

出　　处：《武汉工程大学学报》2023年第5期568-573,共6页Journal of Wuhan Institute of Technology

基　　金：武汉工程大学研究生教育创新基金(CX2019107,CX2022596);国家自然基金(51804222,52174086)。

摘　　要：为了解决隧道群爆破施工时振动强度过大而引起围岩失稳问题,以贵安数据中心特大断面小净距隧道群爆破施工工程为背景,采用浅孔楔形掏槽(SHWC)爆破技术进行施工作业,监测后行洞爆破施工与先行洞支护结构的爆破振动速度,并运用LS-DYNA模拟分析爆破振动强度对隧道围岩应力的影响。研究结果表明:SHWC爆破技术能够有效地控制爆破振动强度,能够将振动速度峰值控制在4.5 cm/s的安全允许标准以内;SHWC爆破有效应力峰值可达117 MPa;爆破地震波传播过程中存在时间上的连续性,形成的反射拉伸波向岩体深部方向延伸与正向传播的爆炸压缩应力波发生干涉叠加,使得岩石被拉伸和压缩而发生破坏;楔形掏槽孔呈“Λ”形结构布置,炸药爆炸产生的有效应力主要集中在掏槽孔底部,使得掏槽区被爆岩体能有效克服周围岩石的夹制作用,提高了掏槽效果,同时,楔形掏槽孔还能进一步扩大掏槽范围。To solve the problem of instability of surrounding rock caused by excessive vibration intensity during blasting construction of tunnel groups,we took the blasting construction of tunnel groups with extra-large section and small clear distance from Gui'an Data Center as a study case.The blasting vibration velocity of the subsequent hole blasting construction and the first hole supporting structure were monitored,and the influences of blasting vibration intensity on the stress of the tunnel surrounding rock were simulated and analyzed by LS-DYNA.The results show that the shallow hole wedge cut blasting technology can effectively control the blasting vibration intensity,and can control the peak vibration velocity within the safety-allowable standard of 4.5 cm/s.The peak effective stress of shallow hole wedge cut blasting can reach 117 MPa.There is time continuity in the propagation process of blasting seismic wave.The reflected tensile wave formed by the explosion extends to the deep part of the rock mass and interferes with the compressive stress wave propagating in the forward direction,which destroys the rock due to tension and compression.When the wedge-shaped cutting hole is arranged in aΛ-shaped structure,the effective stress generated by the explosive explosion mainly concentrates at the bottom of the cutting hole,which enables the blasting rock mass in the cutting area to effectively overcome the clamping of the surrounding rock and improve the cutting effect.At the same time,the wedge-shaped cutting hole can further expand the cutting range.

关 键 词：楔形掏槽爆破 数值模拟 爆破振动 隧道群 

分 类 号：U455.6[建筑科学—桥梁与隧道工程]