锚杆对应力波传播影响的有限元分析

为了获得隧道围岩中应力波的传播特性及支护结构锚杆对应力波传播的影响,通过对爆破荷载模式的分析,得到了的爆破荷载计算的改进模式,并计算了朝东岩隧道开挖中的Ⅳ围岩类型下的爆破荷载,并以爆破荷载为荷载输入,对隧道围岩无支护及有支护情况下的应力波传播特性进行了有限元数值模拟,分析结果表明:在近距离的波传播中,计算结果具有很好的规律性;锚杆对应力波的传播衰减作用明显,其关系可用指数函数来拟合;爆破荷载作用下围岩周边各点的速度是各不相同的,且相差比较大,建议在设计支护系统时,可采用不对称的支护系统。

The Numerical Simulating Propagation of Stress Waves in the Country Rock with Bolting

In order to analysze the effect of the country rock and the bolts in framework on the stress waves in excavating tunnel,by analyzing the blast loading pattern and the attenuation relation and effect of the disperse dynamite package,the multi-hollow blast loading,and the blast loading pattern of the control blast are obtained.Additionally the blast loading of one Tunnel is calculated.the numerical simulation of the propagation of the stress waves in the tunnel country rock is carried out with the blast loading as the load input.The results show that the finite element numerical simulation can quite well simulate the propagation of close quarter stress waves,it is suitable to use finite element simulation for simulating the propagation of close quarter stress waves;the index number function can fit the relation of velocity with distance;the velocity of analyzed dots around the country rock are quite different,so it is suggested to use the unsymmetrical support system.