“短孔卸压降振法”对周边孔爆破减振效果的研究

为了解"短孔卸压降振法"对周边孔最大振速的影响程度,利用多自由面削减能量的原理,首先采用ANSYS-DYNA数值模拟软件对设置"卸压短孔"前后的断面模型进行计算分析,其次结合现场对设置"卸压短孔"前后的隧道断面爆破试验,提取爆破后的振速图进行对比论证,从而得出设置"卸压短孔"前的断面爆破振速大于设置后的断面爆破振速的结论。结果表明:1)使用"短孔卸压降振法"后,断面周边孔振动速度有所降低;2)采用"短孔卸压降振法"进行控制爆破后,隧道开挖轮廓线成型平整,超欠挖现象显著减少。

Study of Influence of Short hole Pressure Relieving and Vibration Reduction Method on Blasting Vibration Reduction Effect of Peripheral Holes

In order to study the influence of short hole pressure relieving and vibration reduction method on the blasting vibration reduction effect of peripheral holes, the tunnel cross section model before and after setting pressure reducing short holes are calculated and analyzed by ANSYS DYNA numerical simulation software; the blasting tests are carried out on tunnel cross section before and after setting pressure reducing short holes; and then comparison is made on vibration velocity diagrams collected before and after setting of pressure reducing short holes. The results show that: 1) The blasting vibration velocity of peripheral holes after using short hole pressure relieving and vibration reduction method is smaller than that before using short hole pressure relieving and vibration reduction method. 2) The tunnel excavation contour line goes smooth and shaped; and the overbreak and underbreak times have been reduced by using short hole pressure relieving and vibration reduction method.