冻结立井模型爆破振动信号的小波包分析

从能量分布特征角度研究爆破振动信号,以达到认识爆破振动危害并提出危害控制方法的目的。结合冻结立井爆破模型试验,获取冻结岩壁指定点爆破振动信号,采用db6小波基对爆破振动信号进行小波包分析,得到各信号不同频带能量分布,研究了高程差、等效距离对振动信号能量衰减规律的影响,利用量纲分析法建立了能量预测公式,并通过实测数据回归分析验证了其正确性。结果表明:各测点振动信号能量随着时间的变化表现为高频部分衰减快、低频部分衰减慢的特征;爆破振动能量分布范围广泛,主振频带较宽且由多个分振频带组成;随着高程的增加、传播距离的增大、能量有向低频集中的趋势;能量大小与药量成正比,与等效距离成反比;结论为鄂尔多斯盆地冻结岩层爆破能量衰减规律、安全性评价提供理论依据。

Wavelet packet analysis of blast vibration signals of freezing shaft model

Blasting vibration signals were studied from the perspective of energy distribution characteristics，with the purpose that blasting vibration hazards can be understood and hazard control method can be developed.The vibration signals of key points on frozen wall were received through the blasting model test of frozen shaft in Meilinmiao mine，China.The gained signals were analyzed by using wavelet db6，then the energy distribution of the signals in different frequency bands was obtained.The effect of height difference and propagation distance on the attenuation law of vibration signal energy were also studied.Besides，the prediction formula of energy was established with dimensional analysis，and the correctness of the formula had been verified by the regression analysis of measured data.The results show that:the attenuation of vibration signal energy in high-frequency part is fast，whereas slow in low-frequency part.Blasting vibration energy is widely distributed，and the dominant frequency band consists of many sub-bands.With height and propagation distance increasing，the blasting vibration signal energy has a tendency to concentrate in low frequency.Energy value is proportional to the equivalent amount of explosive and inversely proportional to the equivalent distance.This conclusion provides a theoretical basis for the attenuation law of blasting energy and the safety evaluation of blasting vibration for frozen rock stratum in Ordos basin.