摘要
钻爆法在隧洞开挖中得到广泛应用,通常采用光面爆破以达到成型质量要求,但在小断面隧洞中,特别是遇到不良地质条件时,受洞内钻孔条件及装药等限制,难以达到理想的轮廓控制爆破效果,从而影响围岩安全稳定,也会导致后期支护及衬砌成本增加。针对上述问题,依托小断面水工隧洞开展现场爆破试验,探究聚能水压爆破技术应用于不良地质小断面隧洞的爆破参数,利用三维激光扫描技术对轮廓开挖质量进行分析与评价,主要结论如下:(1)超欠挖检测结果表明,同种地质条件下,聚能爆破相对于常规爆破可降低超挖量与欠挖量分别为40.8%和54.2%;(2)通过不同炮孔布置方式下的爆破结果对比分析发现,在弧顶与边墙连接处可不布设孔,利用聚能效应控制成型,可减少拱肩处的超挖;(3)在Ⅳ类围岩的粉砂质泥岩和层状砂岩中,壁面平整度受爆破参数影响较小,主要由岩性决定,且层状砂岩相比粉砂质泥岩平整度可提高30%以上。综上所述,在小断面水工隧洞中合理应用聚能水压爆破技术,可有效提高光面爆破下的隧洞壁面成型效果。
The drilling and blasting method is widely used in tunnel excavation.Typically,smooth blasting can meet the quality formation requirements.However,achieving ideal contour control blasting effects and ensuring the safety and stability of surrounding rock mass are challenging due to limitations in drilling conditions and charging in small section tunnels,especially when encountering adverse geological conditions.This often results in increased costs for subsequent support and lining.To address these issues,on-site blasting tests were conducted based on small-section hydraulic tunnels to explore applying energy-gathering hydraulic blasting technology to improve blasting parameters in poor geological conditions.The main conclusions from analyzing and evaluating the quality of contour excavation using 3D laser scanning technology are as follows:(1)The results indicate that shaped charge blasting can reduce over-excavation and under-excavation by 40.8%and 54.2%,respectively,compared to conventional blasting under the same geological conditions.(2)A comparative analysis of blasting results under different borehole arrangements shows that no boreholes are needed to connect the arch crown and the side wall.Utilizing the shaped charge effect to control can reduce over-excavation at the arch shoulder.(3)In fourth-class surrounding rock mass,including silty mudstone and stratified sandstone,the smoothness of the wall surface is less affected by blasting parameters and is promarily determined by lithology.Moreover,the smoothness of stratified sandstone can be improved by more than 30%compared to silty mudstone.In summary,the reasonable application of shaped charge water pressure blasting technology in small cross-section hydraulic tunnels can improve tunnel wall shaping under smooth blasting conditions.
作者
黄高翔
许国庆
姚强
杨旭
陈星艮
李洪涛
HUANG Gao-xiang;XU Guo-qing;YAO Qiang;YANG Xu;CHEN Xing-gen;LI Hong-tao(Sichuan Academy of Water Conservancy,Chengdu 610072,China;College of Water Resource&Hydropower,Sichuan University,Chengdu 610065,China)
出处
《爆破》
北大核心
2025年第1期89-96,共8页
Blasting
基金
国家自然科学基金(51809188)
国家重点研发计划(2023YFC3008305)。
关键词
聚能爆破
水压爆破
不良地质
小断面隧洞
三维激光扫描
shaped charge blasting
hydraulic blasting
adverse geology
small section tunnel
3D laser scanning
