大断面软弱围岩隧道光面爆破技术研究  

Study on Smooth Blasting Technology of Large-section Tunnel in Soft Rock Mass

作　　者：冯畅 吴室谕 袁正兵 FENG Chang;WU Shiyu;YUAN Zhengbing(Chongqing Yuxiang Double Line Expressway Co.,Ltd.,Chongqing 401121,China;JSTI Group Co.,Ltd.,Nanjing 210019,China)

机构地区：[1]重庆渝湘复线高速公路有限公司,重庆401121 [2]苏交科集团股份有限公司,南京210019

出　　处：《现代交通技术》2023年第4期21-26,共6页Modern Transportation Technology

基　　金：住房与城乡建设部山地建筑绿色建造关键技术研究(2022—K—120)。

摘　　要：为解决大断面软弱围岩隧道的超欠挖、超耗问题,以武隆隧道、白马山2号隧道为工程背景,对光面爆破的工艺流程、爆破参数进行优化设计,采用三维激光扫描仪对光面爆破前、后的开挖轮廓进行断面扫描,揭示了光面爆破的作用机理,结合断面数据分析了光面爆破的作用效果、技术优势与经济效益。结果表明:进行光面爆破时,不同炮孔间平整断裂面的形成促进了开挖岩壁的连续性、光滑性和完整性;采用光面爆破能显著减少隧道超挖,使平均超挖由35 cm以上降低至10~20 cm,且显著降低了喷射混凝土的超耗率,大幅节省了每延米的开挖成本。To eliminate the overbreak and over-consumption of the large-section tunnel in the soft rock mass,the construction process and blasting parameters of smooth blasting were designed and optimized based on the projects of the Wulong Tunnel and Baimashan No.2 Tunnel.Excavation sections before and after smooth blasting were scanned by employing a three-dimensional laser scanner.After that,the mechanism of smooth blasting was analyzed.The explosive effect,technical effectiveness,and economic benefit of smooth blasting were then determined.The results indicate that the smooth blasting contributes to the continuity,smoothness,and integrity of the excavated rock surface by creating a flat fracture surface between various blasting holes.The implementation of smooth blasting significantly reduces the overbreak of the tunnel,with the average overbreak falling from over 35 cm to 10~20 cm.In addition,the overconsumption rate of shotcrete is dramatically reduced,resulting in considerable savings in excavation cost per extended meter.

关 键 词：隧道工程 光面爆破 超欠挖控制 爆破参数设计 爆破机理 经济效益 

分 类 号：U455.6[建筑科学—桥梁与隧道工程]