论文部分内容阅读
为减小爆破对隧道围岩的损伤,在传统光面爆破装药结构基础上,设计一种在炮孔一侧安放PVC-U材料来保护隧道围岩的装药结构,并分析了该方法的作用机制。为分析和验证PVC-U管对隧道围岩损伤的防护效果,利用Φ100mm的霍普金森试验装置进行隧道围岩损伤防护试验,从试件宏观破坏、应力波衰减和能量变化3方面进行了分析。结果表明:防护材料改变了岩石的受力状态,当防护材料厚度从0增加到6.24mm时,无防护材料的试件的破坏程度比有防护材料的试件严重,且随着防护材料厚度的增加破坏程度不断减小;试件的应力峰值呈不断降低趋势;应力峰值的降低率不断增加;耗散能与入射能比值从61.08%下降到39.97%。可见,防护材料对岩石冲击损伤具有一定防护作用。该方法在某巷道掘进中得到应用,并取得了良好效果。
In order to reduce the damage of tunnel surrounding rock by blasting, based on the traditional smooth blasting charge structure, a charge structure was designed to protect the surrounding rock of tunnel by placing PVC-U material on one side of the blast hole, and the method was analyzed The mechanism of action. In order to analyze and verify the protective effect of PVC-U pipe on the tunnel surrounding rock damage, we use the Hopkinson test rig with Φ100mm to carry out the tunnel surrounding rock damage protection test, which is analyzed from macroscopic failure, stress wave attenuation and energy change . The results show that the protective material changes the stress state of the rock. When the thickness of the protective material increases from 0 to 6.24 mm, the failure of the unprotected specimen is more serious than the specimen with the protective material. With the thickness of the protective material The increasing of the damage degree decreases continuously. The stress peak value of the specimen decreases continuously. The decreasing rate of stress peak increases continuously. The ratio of dissipation energy to incident energy decreases from 61.08% to 39.97%. It can be seen that the protective material has a certain protective effect on rock impact damage. The method has been applied in a roadway excavation and has achieved good results.