深埋隧洞爆破开挖地应力瞬态卸荷诱发围岩振动控制方法研究

Study on controlling methods for transient unloading inducing rock vibration due to blasting excavation of deep tunnels

爆破引起的开挖面上岩体地应力快速释放是深埋洞室爆破施工主要动力扰动因素之一。针对深埋圆形隧洞全断面毫秒延迟爆破开挖过程,分析开挖面上地应力瞬态卸荷诱发围岩振动的力学机制及其影响因素,在此基础上从掏槽方式选择、孔网参数布置、起爆网路优化的角度详细探讨诱发振动的控制方法。研究表明,通过设计合理的钻爆参数可降低开挖面上的地应力、延长卸荷持续时间、减小开挖面的大小,从而达到控制地应力瞬态卸荷诱发围岩振动的目的。研究成果对深地资源开采、深地空间开发利用等相关行业的深埋洞室爆破施工具有一定的指导作用。

During blasting excavation of deep tunnels,the rapid in-situ stress release occurring on blast-created free surfaces is one of the major dynamic disturbances. For a deep circular tunnel which is excavated with the full-face millisecond-delay blasting method,the mechanism and influence factors of rock vibration induced by the transient unloading was analyzed,and vibration control methods were discussed in detail from the perspectives of cutting modes,blasthole arrangements and initiation sequences. The results show that properly designing drilling and blasting parameters can reduce initial stress levels on the excavation surfaces,prolong the duration of the transient unloading and reduce sizes of the excavation surfaces,and that,as a result,rock vibration induced by the transient unloading can be effectively controlled. The research work can be applied to blasting construction of deep tunnels in the industries of deep resource exploitation and deep space utilization.