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微差爆破间隔时间的确定,对高安全性振速指标下的城市复杂环境隧道爆破设计具有重要作用。以重庆渝中连接隧道爆破工程为背景,在采用多段定制非电雷管条件下,研究根据爆前、爆后实测雷管延迟时间进行精确爆破设计的方法,用非电雷管实现逐孔掏槽爆破以满足严苛低振速控制要求。比较Hilbert-Huang变换(HHT)理论中用于雷管延迟识别的瞬时能量法与EMD识别法的识别能力,发现EMD识别法识别率为66%~90%,比瞬时能量法高1/3以上。爆后用EMD识别法辨别的延迟时间证明实际爆破微差间隔在爆前样本雷管起爆精度范围之内。为准确控制爆破振动,以识别雷管实际延迟时间和振动波形图为依据调整了爆破参数。现场振动监测数据表明:采用多段位定制非电雷管缓解了雷管段别不足的矛盾,根据实测结合EMD识别法识别获得雷管延迟特性进行爆破设计对于严苛振速控制是可行的,在全程爆破振速不超0.8 cm/s条件下进尺1.8 m,通过2次爆破完成上台阶掘进。这一方法对今后城市密集建筑群下浅埋隧道爆破安全施工具有一定的参考价值。
The determination of the interval time of the microdispensal blasting plays an important role in the tunnel blasting design of the urban complex environment under the high safety speed index. Taking Chongqing Yuzhong tunnel tunnel blasting project as a background, under the conditions of multi-section custom non-electric detonator, the exact blasting design method based on the detonation time before and after the detonation was explored, and the hole-cut blasting with non- Harsh and Low Vibration Control Requirements. The recognition ability of instantaneous energy method and EMD method for detonator delay identification in Hilbert-Huang transform (HHT) theory is compared. The recognition rate of EMD method is 66% ~ 90%, which is 1/3 higher than that of instantaneous energy method. The delay time identified by EMD after blasting proves that the actual blasting microsecond interval is within the pre-blasting sample detonation initiation accuracy range. In order to accurately control the blasting vibration, the blasting parameters were adjusted based on the actual detonation time and vibration waveform of the detonator. The on-site vibration monitoring data show that the multi-position custom non-electric detonator alleviates the shortcomings of the detonator section. It is feasible to identify the detonation delay characteristics of the detonator based on the actual EMD identification method for severe vibration control. At a speed of not more than 0.8 cm / s, the footage was 1.8 m and the tunneling was completed by two blasting. This method has certain reference value for the blasting safety construction of shallow tunnel under the urban dense buildings in the future.