连拱隧道爆破荷载效应分析

针对连拱隧道设计、施工中存在的问题,采用三维有限差分程序FLAC3D2.0,对连拱隧道进行了爆破荷载数值模拟分析,分析结果表明:在相同条件下,爆破振动受围岩弹性模量E的影响较大,围岩越弱、振动越强烈,反之,围岩越硬、振动越小;爆破应力波最初以冲击波的形式向外传播,随着波阵面不断向外传播,冲击波发生衰减,逐渐从强冲击波衰减成弹性波和地震波,围岩越好、衰减速度越快;爆破振动对隧道的危害主要由一次齐爆最大单响装药量确定;爆破对临时支护的影响较显著,应采用有效措施保护中墙。

Blasting Load Effect Analysis of Dual-arch Tunnel

In the light of the problems in design and construction of the multi-arch tunnel,in this paper three-dimensional finite difference program FLAC3D2.0 has been used to carry on a numerical simulation analysis of blasting load of multi-arch tunnel.The results show that：under the same condition,blasting vibration is greatly influenced by elastic modulus E of the surrounding rock.The weaker surrounding rock is,the stronger the vibration is,and vice versa.Blasting stress wave is initially transmitted outward in the form of shock waves,which gradually attenuates and turns into elastic waves and seismic waves.The better surrounding rock is,the higher the speed of the attenuation is.Damage to the tunnel of blasting vibration is mainly determined by the maximum charge weight of single shot for the single simultaneous blasting.Blasting influences temporary support significantly,so effective measures must be taken to protect the midboard.