Study on mine cracking by millisecond blasting in water coupling hole

Abstract：To improve mine gas drainage rate by blasting, the simulation blasting tests of one shot hole and three shot holes have been finished.In the test, the initiation can be accurately controlled by the Nonel.One shot hole test results show that water coupling charge is the best charge.Three shot holes test results show that the blasting effect of millisecond blast is superior to instantaneous blasting, and millisecond blast can make not only main cracking but also lots of micro-cracking.

Keyword：millisecond blast;water coupling;blasting cracking;