【摘要】 以重庆渝中连接隧道爆破工程为例,利用Hilbert-Huang变换分析爆破振速信号,对比瞬时能量法与EMD识别法识别雷管实际延时时间效果。研究结果显示,瞬时能量法识别率在30%~60%,低段别平均识别率仅35%;而EMD识别法识别率为66%~90%,各段识别率平均较瞬时能量法高约30%。对不同药量单孔爆破实验分析表明,单孔药量1.2 kg的起爆能量衰减时间为150 ms。常规药量下雷管间微差起爆间隔大于50 ms以上时可用瞬时能量法识别起爆时刻;城市隧道用50 ms以下小间隔微差爆破时用EMD识别法识别率较高。更多还原

【Abstract】 The exact identification of a detonator’s actual firing time is a basis to analyze the relationship between millisecond interval and blasting vibration velocity,it is of great significance to control blasting vibration for tunnel excavation under complex urban environment. Here, taking Chongqing city Yuzhong connecting tunnel blasting engineering as an example,the blasting vibration velocity versus time data were analyzed with HHT( Hilbert-Huang transformation). The denotators’ actural time-delay effects using the instantaneous energy method were compared with those using the EMD method. The study results showed that the instantaneous energy method identification rate is 30% ~60%,the average identification rate detonators of lower segment is only 35%; while the EMD method identification rate is66% ~ 90%,the identification rates of all segments about 30% higher than those of the instantaneous energy method. The analysis for single-hole blasting tests with different blasting charges indicated that the attenuation time of a single-hole blasting’s energy is nearly 150 ms with 112 kg blasting charge; the instantaneous energy method can be used to identify the initial blasting instant under the condition of a usual blasting charge if time delay of detonators is longer than 50 ms;however,the identification reliability of the EMD method is relatively higher if the time delay of fetonators in millisecond blasting is less than 50 ms for urban tunnel excavation.更多还原