钻爆法隧道原位扩建的振动效应分析与爆破方案比选  

Blast vibration analysis and blast scheme optimization for the tunnel in-situ expansion

作　　者：吕荔炫 LYU Li-xuan(Fuzhou Planning&Design Research Institute Group Co.,Ltd.,Fuzhou 350108,China)

机构地区：[1]福州市规划设计研究院集团有限公司,福州350108

出　　处：《工程爆破》2022年第5期135-142,共8页Engineering Blasting

摘　　要：以福州市马尾隧道扩建工程为依托,通过精细化数值模拟对掏槽/无掏槽爆破方案进行比选。将延时爆破荷载逐段施加在各排孔段位的爆破轮廓线上,研究了扩建爆破时邻洞衬砌的振动效应和传播路径上的衰减规律。数值模拟结果表明:邻洞背爆侧振速远远小于迎爆侧(平均降幅为68.7%);迎爆侧衬砌振速峰值总体呈现为上大下小;爆破振动在岩体中的水平传播中呈对数衰减,尤其是空洞的存在显著降低了爆破振动效应。将优化后的无掏槽爆破方案应用于工程实践,并对爆破振动进行跟踪监测,与数值结果较为吻合,且均在安全阈值之内。优化无掏槽方案较好地利用了既有空洞和重力作用,单耗低振动轻,宜作为隧道扩建工程的爆破首选方案。Based on the expansion project of the Mawei Tunnel in Fuzhou,the cutting and non-cutting blasting schemes were carefully simulated and then compared.The millisecond blast loading was gradually applied to the contour line of each row hole.The vibration effect at neighbor tunnel lining and the vibration attenuation along the propagation path were well focused.Numerical simulation results show that:the velocity histories at the arch feet of backward side were much lower than its counterpart at the forward side(the average decrease was 68.7%).The peak velocity at the upper part of lining was generally larger its counterpart at the bottom part.The vibration effect attenuated logarithmically along the horizontal propagation path through rock mass,and the existence of cavity reduced the vibration effect significantly.The non-cutting scheme was applied into practice and the blasting vibration was also monitored.The monitoring data were under the vibration safety threshold and agreed with numerical results well.The optimized non-cutting scheme,which utilized the existing cavities and gravity and reduced the unit consumption and vibration effect,could be well used for the tunnel in-situ expansion projects.

关 键 词：隧道原位扩建 爆破方案比选 数值模拟 振动效应 

分 类 号：TD235[矿业工程—矿井建设] U455[建筑科学—桥梁与隧道工程]