定制雷管微差时间实测与识别法在城市隧道爆破设计中的应用

 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。比较了Hilbert-Huang变换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70%～90%，比瞬时能量法高约30%。EMD识别法辨别的延迟时间证明实际爆破微差间隔在样本精度范围之内。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。

APPLICATION OF MEASURING AND IDENTIFYING DETONATION TIME OF CUSTOMIZED DETONATOR IN BLASTING DESIGN OF URBAN TUNNEL

Under the condition of safety requirement of high standard for blasting vibration，it plays an important role in tunnel blasting design that the interval time of millisecond blasting is accurately detimined in the complex urban environment. With the engineering background of Chongqing Yuzhong connecting tunnel blasting，an accurate blasting design method basing on the measured delay time is proposed，in which multi-deck customized non-electric detonator is adopted to meet the severe low-vibration control requirement in single hole cutting blasting. The identification ability on detonator’s delay recognition of instantaneous energy method in the Hilbert-Huang Transform theory is compared with EMD method. The recognition rate of EMD method is 70%～90%，about 30% higher than the instantaneous energy method. The delay time identified by the EMD method proves that actual millisecond interval is in the accuracy range of samples. On the basis of vibration wave graph and actual delay time，blasting parameters are adjusted for controlling blasting vibration accurately. Field vibrate monitor data shows that using multi-deck customized non-electric detonator can alleviate the disparity about lacked detonator delay，and single hole cutting can meet severe low vibration controlled requirement； the blasting design combined with measured detonator delay time identified by EMD method is feasible to severe vibration control. Blasting advance per attack can reach to 1.8 m under the condition of vibration velocity is less than 0.8 cm/s，and excavations of upper bench are finished by blasting twice. This design method has a certain reference value for shallow buried tunnel safety blasting operation in urban crowded buildings environment.