不同爆破掏槽形式的反应频谱综合分析

SPECTRUM COMPREHENSIVE ANALYSIS ON BLASTING SIGNALS UNDER DIFFERENT CUTTING METHODS

  • 摘要: 针对相同的地质条件,采用相同的爆破耗材,分别设计了直眼掏槽、单楔形掏槽、双楔形掏槽共计三种掏槽方式。进一步实施了在不同掏槽方式情况下的光面爆破试验。依据爆破效果,发现直眼掏槽方式更有利于爆破硐室成型,而单楔形和双楔形掏槽更有利于岩石的破碎及岩渣抛掷。从加速度反应谱、速度反应谱和位移反应谱角度对爆破后体系的动力响应予以分析,发现直眼掏槽无论是加速度响应峰值,还是速度和位移响应峰值均为最大,而双楔形掏槽的上述对应响应峰值均为最小,并且直眼掏槽能量更多集中在低频部分,对于工程稳定性更为不利。反应谱特征充分说明在该工程体系中,宜采用双楔形掏槽方式进行爆破设计。同时,需指出的是,该文获得的位移、速度和加速度反应谱,与爆破振动波自身的波动特征并不相同,该反应谱是爆破振动波动与结构体系的动力响应之间的一个联系,可为结构体系的最大响应峰值提供参考,并能为爆破参数设计提供理论依据。

     

    Abstract: According to the principle of blasting damage, three kinds of cutting methods were designed, e.g., straight parallel hole cutting, single wedge cutting and double wedge cutting. Then, the blasting tests under different cutting methods were carried out in the field. The results show that all the three cutting methods can achieve good utilization ratio of blasting holes. The blasting effect of straight parallel hole cutting is good. The rock slag sizes of single wedge and double wedge cutting are uniform, which is beneficial to slag extraction. Moreover, the acceleration response spectrum, velocity response spectrum and displacement response spectrum of each cutting method were analyzed and compared separately. It is found that the straight parallel hole cutting have the maximum spectrum values among the three methods, and the spectrum mainly concentrates on the low-frequency part, while the double wedge hole cutting has the minimum spectrum values. It is obvious that the double wedge hole cutting is most suitable for the excavation system. It should be noticed that these spectrums calculated and obtained by blasting vibration monitoring are not the same as the vibration wave, which is a link between blasting vibration itself and dynamic response of the system. This study will provide a reference for the calculation of maximum response and a theoretical background for the design of blasting parameters.

     

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