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众所周知,岩体特性对破岩过程有极大的影响,为了寻求岩体质量和节理方位对隧道爆破的影响,进行了模拟爆破和现场测试。震动波的传播,部分地受到节理面的约束,已观测到爆破结果(如碎块的平均尺寸和破碎区的深度与断面积)受节理方位的影响极大。由此得出结论,在有节理面垂直于隧道轴的岩层中,需要用有大容量铲碴斗的装碴设备和较深的炮孔。而岩层节理平行于隧道轴时,则需用数量较多的炮孔。此外,发现单位炸药消耗量(kg/m~3)也直接与岩体质量(Q)有关。在有节理平行于隧道轴的弱岩层条件下,则要求优化爆破进尺(一次爆破推进距离)、减少单位炸药耗量和超挖。在不良和中等质量岩体的条件下,采用周边光面爆破技术似乎是个关键,它有利于减少超挖,降低支护成本,提高巷道稳定性。
It is well-known that the characteristics of rock mass have great influence on the rock breaking process. In order to seek the influence of rock mass quality and joint orientation on the tunnel blasting, simulated blasting and field testing are carried out. The propagation of vibrational waves is partially constrained by the joint surfaces and the blasting results (eg, the average size of the fragments and the depth and area of the crushing zone) have been greatly influenced by the joint orientation. This concludes that in rock formations with joint planes perpendicular to the tunnel axis, ballasting equipment with large scoops and deeper blast holes are required. The rock joints parallel to the tunnel axis, you need to use a large number of holes. In addition, it is found that unit explosive consumption (kg / m ~ 3) is also directly related to rock quality (Q). Under conditions of weak rock with joints parallel to the tunnel axis, it is required to optimize the blasting footage (one blasting propulsion distance) to reduce unit explosives consumption and over excavation. The use of peripheral smooth blasting appears to be a key issue under poor and medium-quality rock mass, which helps reduce over-excavation, reduce support costs and improve roadway stability.