节理裂隙层状岩体隧道掘进爆破参数试验研究  

Experimental study of parameters of tunneling blasting in jointed layered rock mass

作　　者：徐帮树[1] 张万志[1] 石伟航 郝广伟 刘性锋 梅洁[1] XU Bangshu;ZHANG Wanzhi;SHI Weihang;HAO Guangwei;LIU Xingfeng;MEI Jie(Geotechnical and Structural Engineering Research Center,Shandong University,Jinan,Shandong 250061,China;Shandong Luqiao Group Co Ltd,Jinan,Shandong 250011,China)

机构地区：[1]山东大学岩土与结构工程研究中心,山东济南250061 [2]山东省路桥集团有限公司,山东济南250011

出　　处：《中国矿业大学学报》2019年第6期1248-1255,共8页Journal of China University of Mining & Technology

基　　金：国家自然科学基金青年科学基金项目(50909056);山东省自然科学基金项目(ZR2014EEM014)

摘　　要：为解决爆破开挖引起的隧道拱部易离层以致超挖、掌子面底部欠挖的工程问题,研究了节理裂隙发育的水平层状岩体大断面隧道掘进爆破参数.依托蟠龙山隧道工程,开展了现场掘进爆破试验和层状岩体破坏机理分析,优化了隧道开挖的光面爆破参数、掏槽孔布设方案和最大单孔装药量参数.对比分析爆后围岩特征、毛洞轮廓超欠挖和围岩变形,发现采用掘进爆破优化参数的洞室开挖成型效果更好.结果表明:采用优化爆破参数进行开挖,可抑制拱顶岩体大面积离层,明显减小拱肩围岩层间错台高度和宽度,避免掌子面中底部岩体"鼓肚"现象;隧道轮廓最大线性超欠挖明显减小,上台阶断面平均超挖面积减小59.3%;至开挖完成15 d,拱顶沉降和拱腰水平收敛量测值较优化前分别减小了21.6%和18.3%.In order to solve the problems of overbreak at the arch and underbreak at the bottom of the tunnel face caused by blasting excavation, the blasting parameters of large section tunnels in horizontal layered rock mass with joints and fissures were studied. Based on the Panlong mountain tunnel project, the blasting excavation tests were carried and the failure mechanism of horizontal layered rock mass was analyzed. The smooth blasting parameters, the layout scheme of cut holes and the maximum charge in single hole for the tunnel excavation were optimized. By comparing and analyzing the failure characteristics, the values of overbreak and underbreak and the deformations of surrounding rock mass after blasting excavation, descovered that the tunnel excavation outline was better using the optimized blasting parameters. The results show that the large-area separation of roof rock mass is restrained, the stepped height and width of the arch shoulder rock mass are significantly reduced, and the underbreak of rock mass at the bottom of the face is effectively avoided by using the optimized blasting parameters. The maximum linear overbreak and underbreak are obviously reduced and the average overbreak area of the upper step is reduced by 59.3%. 15 days after excavation, the measured values of the arch crown settlement and the horizontal displacement of the arch lumbar are decreased by 21.6% and 18.3%, respectively.

关 键 词：层状岩体 掘进爆破 现场试验 爆破参数 节理裂隙 

分 类 号：U451.2[建筑科学—桥梁与隧道工程]