Application of Hole-by-hole Ignition in Pre-Splitting Blasting

摘要

In order to reduce the impact of pre-splitting blasting vibration on stability of high and steep slope, Lanjian Iron Mine carried out an experimental study on the pre-splitting blasting technology of hole by hole. Referring to the theory of millisecond delay blasting and the shaped crack mechanism of pre-splitting blasting, blasting design was made according to three principles including unchanging charging structure of pre-split holes, pre-split and primary holes blast hole by hole and insurance of initiation network. The results of blasting practices showed that though using the technique of hole by hole blasting, which was more than that though using the millisecond blasting between rows,and reduced the damage on steep slope by vibration, the ratio of half-wall hole imprint was up to 96.3%, and the ratio of vibration was lowered by 50%～80%. Meanwhile, with the hole by hole blasting technique, the pre-splitting crack's throughout, spreading out and producing of pre-splitting outline, and the quality of slope produced by pre-splitting blasting were insured.