隧道开挖过程中软弱围岩的爆破技术研究

根据软弱围岩具有岩体较破碎、节理较发育、层面粘结力弱等特点，本文通过分析隧道掘进过程中爆破作用对软弱围岩的扰动影响、爆破后对洞室造成的超欠挖以及洞室成型后自然拱的变形甚至掉块、塌顶，得出了软弱围岩在爆破后稳定性差及变形不规律的特征。并在严格控制钻孔精度、周边孔线装药密度、周边炮眼间距布置、装药结构四个主要因素的情况下，进行了大量的实验和洞室成型后连续的监控量测并对这四个主要影响因素的爆破参数进行了优化，得出了软弱围岩的爆破方法。

Research on blasting technique of soft rock in the process of excavating tunnel

According to the main characteristics of soft rock in rock broken, joints development and weak cohesion of level, this thesis insist that soft rock is instability, irregular deformation after blas- ting by analyzing the disturbing influence on soft rock, the back break of grotto and the deformation, sloughing even collapse of natural arch during the tunnel drive. It optimizes blasting parameters by making experience and the serious of monitoring measurement which under the strictly controlling on the precision of drilling, the density of hole - line, the spacing layout of drill - hole and the charging structure. Based on that, the thesis proposes the blasting scheme for soft rock basing on the many ex- periment and continuous monitoring measurement after cavern forming.