The finite element software of ANSYS is employed to analyze the influence of rock crack length and type
different diameters of explosive
pre-split blasting and smooth blasting on dynamic stress intensity factors of crack-tip. The results indicate that the pre-split slot is extended mainly from the crack at the blasting hole under the blasting shock wave and detonation gas loading; with the increase of the diameter ratio of explosive to blasting hole
the dynamic stress intensity factor increases; but the curve form of dynamic stress intensity factor keeps unchangeable; the later peak value of smooth blasting is greater than that of pre-split basting because of the existence of free face.