隧道光面爆破护壁装药结构数值模拟分析

利用仿真软件,分别对PVC管与聚氨酯泡沫新型护壁结构的不耦合装药和耦合装药2种工况的炮孔爆破过程进行了数值模拟分析。结果表明:耦合装药结构爆破过程中,炮孔周边单元测点应力的变化规律与不耦合装药结构大致相同;该新型护壁结构对爆炸应力波具有衰减作用,可延长爆炸应力波的传播时间;炸药爆炸时高温高压使聚氨酯泡沫材料产生形变,消耗掉部分爆炸能量,导致传播到空气和岩体上的应力峰值衰减47.02%～53.78%。

Numerical Simulation Analysis of Wall Protection Charge Structure in Smooth Blasting at Tunnel

Using the simulation software,the blasting process of two different working conditions of uncoupled charge and coupled charge of PVC tube and polyurethane foam new wall protection structure were simulated respectively.The results show that,during the blasting process of the coupled charge structure,the change rule of the stress at the measuring point of the unit around the blast hole is roughly the same as that of the uncoupled charge structure.The new wall protection charge structure can attenuate the blast stress wave and extend the propagation time of the blast stress wave.When the explosive exploded,high temperature and high pressure caused the deformation of polyurethane foam material and consumed part of the explosive energy,resulting in the attenuation of the peak value of stress transmitted to the air and rock mass by 47.02%-53.78%.