对强岩爆隧道进行分区爆破卸压的设计方法

为了研究强岩爆隧道爆破卸压方案及参数设计方法,基于深部岩体分区破裂化现象及高围压爆破破碎机理,提出分区爆破逐级释压的应力主动控制技术,通过理论计算得出高地应力条件下破裂区半径的计算公式,根据分区破裂半径的统计规律确定应力释放部位,并形成分区爆破卸压参数的系统化设计方法。数值模拟结果表明:隧道开挖轮廓线的岩爆判别系数均有不同程度的减小,岩爆发生的可能性大大降低,应力集中部位向爆破卸压破碎区转移。基于分区破裂化原理对爆破卸压参数设计的系统研究,对高地应力隧道采用爆破卸压防治岩爆的设计和施工具有一定的借鉴意义。

Zonal destress blasting for tunnels with strong rock burst

In order to study the destress blasting program and the parameter design method of strong rock burst tunnel, based on the zonal disintegration phenomenon of deep rock mass and the mechanism of high confining pressure blasting, the active stress control technology of staged pressure relief is proposed, the calculation formula of fracture zone radius under high ground stress condition is obtained through theoretical calculation, and the stress release position is determined according to the statistical law of fracture radius in different zones. The results of numerical simulation show that the rock burst discrimination coefficient of tunnel excavation contour is reduced in varying degrees, the possibility of rock burst is greatly reduced, and the stress concentration part is transferred to the blasting pressure relief crushing area. The systematic research on the design of blasting pressure relief parameters based on the principle of zonal disintegration could provide a certain reference for the design and construction of high ground stress tunnel using destress blasting to prevent rock burst.