基于小波变换的时-能分布确定微差爆破的实际延迟时间

TIME-ENERGY ANALYSIS BASED ON WAVELET TRANSFORM FOR IDENTIFYING REAL DELAY TIME IN MILLISECOND BLASTING

在微差爆破工程中,由于所使用的普通延期雷管存在延期误差,设计或选择的延期微差时间往往与实际的有较大出入,影响了微差爆破的效果。确定微差爆破的实际微差延迟时间对优化微差爆破效果、降低爆破地震效应具有重要意义。基于小波变换的时-能密度法具有突出被分析信号能量突变的特点,通过分析监测到的爆破振动信号不同频带的能量随时间的分布情况,能有效地识别出微差爆破中各段雷管的起爆时刻,进而可以确定爆破中所用雷管的实际延期时间,较好地解决上述问题。以某地下工程的微差爆破振动信号进行时-能密度分析为例,对本方法的有效性作了检验。本方法亦可用于分析爆破振动信号在传播过程中能量随时间的衰减规律,对综合研究爆破机理和爆破地震波有指导意义。

In millisecond blasting, the designed or selected delay time is always different from the real one due to the delay errors of ordinary short delay detonators. The problem influences both the effect and successful implementation of blast. It is significant to identify real time of delay in millisecond blasting. The time-energy density analysis based on the wavelet transform has the character of making the abrupt change of signal energy prominent and can effectually identify the blasting moment of short-delay detonators. Then the real time of delay can be ascertained by analyzing the energy distribution of the monitoring signals in millisecond blasting, and the problem mentioned above can be solved successfully. The effectiveness of the proposed method is verified with time-energy density analysis of vibration signals of millisecond blasting in an underground engineering. The method can be also applied to analyze the attenuation laws of energy for blasting vibration signals during the propagation, blasting mechanism and blasting seismic effects in its entirety.