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Abstract 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.
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2015, Vol. 34 
