Abstract: The traditional electric detonator has only five segments,which can not meet the requirement of delay time for the borehole subsection technology.Digital electronic detonator adopts electronic control module,blasting delay time can be arbitrarily set,the minimum delay time can be set to 1 ms,to meet the requirements of completing the blasting process within 130 ms of gas roadway.In addition,the utilization rate of borehole is low due to the increase of rock clip at the bottom of borehole in the deep hole blasting driving of rock roadway in coal mine.In this paper,based on digital electronic detonator,the piecewise cut blasting technology is applied to change the continuous charge in the cut hole to the piecewise charge and realize the piecewise delayed initiation.The new technology was tested in Gubei Coal Mine in Huainan.The results show that,based on digital electronic blasting cap,the single-cycle footage increases by about 0.7 m,the hole utilization rate increases by about 10%,and the average lumpiness decreases by about 15% compared with the original scheme,which provides a good condition for the next cycle.It is estimated that the monthly footage can be increased from 65 m to 100 m,which improves the tunneling efficiency on the whole.As the first test of digital electronic detonator in underground rock tunneling,digital electronic detonator can still be used normally under high gas condition,which can provide reference for similar rock tunneling blasting construction in the future.

Key words: mine blasting,digital electronic detonator,hole sublevel,cut blasting,single cycle feed