层状围岩节理倾角对隧道光面爆破效果的影响

Influence of Joint Angle of Laminated Surrounding Rock on Smooth Blasting Effect of Tunnel

同种爆破参数对不同类型地层开挖时体现的爆破效果相差明显,运用LS-DYNA软件建立不同倾角下不同层厚节理地层的隧道爆破模型,重点研究不同倾角节理时同种周边眼光面爆破参数下的爆破效果,以探明层状节理隧道爆破规律。结果表明:层状节理围岩下隧道爆破产生的超欠挖明显,且由于重力作用下节理岩块脱落效果及节理面上法向应力较小,超欠挖量随倾角的增大而减小;节理和岩体爆破时吸收的能量也与倾角呈正相关关系,且节理吸收能量约为岩体的15%~20%。

The blasting effects of the same blasting parameters are obviously different for the excavation of different types of stratum.The tunnel blasting model of joint strata with different thickness and different dip angles was established by LS-DYNA software,and the blasting effect of the same periphery hole blasting parameters with different dip angles joints was studied in order to explore the law of tunnel blasting with layered joints,The results show that the tunnel blasting under layered jointed rock has obvious over-under-excavation,and the over-under-excavation amount decreases with the increase of dip angle due to the falling off effect of jointed rock block under the action of gravity and the small normal stress on the joint surface.The energy absorbed by joints and rock mass during blasting is also positively correlated with the dip angle,and the energy absorbed by joints is about 15%~20%of rock mass.