不同方向爆炸荷载作用下地下洞室抗爆效果研究

基于抗爆模型试验结果,利用数值分析方法,研究不同方向爆炸荷载作用下地下洞室的抗爆效果。通过对比分析地下洞室爆炸压应力时程曲线和动态裂纹分布形态,发现数值分析和试验的应力波曲线和锚固洞室围岩动态裂纹分布比较相似,这说明数值分析的结果比较合理。锚固洞室在相同当量爆炸荷载作用下,顶爆产生的位移最小,其次拱部侧爆,最大是直墙侧爆,并且直墙侧爆产生最大位移的位置是侧墙墙底,而不是离爆源最近的洞壁位置。在爆炸荷载作用,由于锚杆加固作用,在锚杆间发生受拉"劈裂",同时还在锚固区内以及锚固区末端发生"层裂"现象。在相同当量顶爆、拱部侧爆和直墙侧爆作用下,毛洞和锚固洞室的位移和动态裂纹分布形态相似,经过锚杆加固的洞室抗爆能力都得到提高。

Research on Anchored Effect of Tunnels under Explosion Load in Different Directions

Based on the results of model tests,anchored effect of tunnels under explosion load in different directions was studied by numerical analysis.Through the compare pressure temporal curves and the distribution of dynamic cracks of model tests and numerical analysis,they are similar,which shows that numerical data are reliable.When tunnels reinforced by rockbolts are attacked under the same equivalent explosion,the maximal displacement of top explosion is smallest,and the maximal displacement of side explosion is largest.The location of the maximal displacement under side explosion is the bottom of side wall.Because of rockbolts,splitting by tensile appears between the rockbolts,and spalling happens in the anchorage zone and the end of the anchorage zone.Under the same equivalent explosion of top explosion,arch explosion and side explosion,the distribution of displacement and dynamic cracks is similar,and the antiknock ability of tunnels reinforced by rockbolts is improved.