中国矿山工程

Making sure the length of stemming in the bore hole which can keep an effectively exvacation. What’s more, the relative calculating theory didn’t consider the acceleration change which must be disparate with the reality. This paper will improve the calculation considering the previous methods as well as combine with the actual works to select the proper calculating range, which shows that the improved method is basically consistent with the previous project experience, confirming the rationality of this method.