Study on the Effect of Minimum Resistance Line on Blasting Effect of Bench Model

To study the effects of minimum resistance line on the step model exploding, a blasting experiment was conducted using pure concrete bench model with the similarity criterion. This experiment was monitored and analyzed by a high-speed camera, a transient signal measuring instrument, and a super dynamic strain tester. It was found that with the value increase of W, the fragmented quality of blasted pile and the largest size of fragmentation increased, while the initial velocity of free surface, and the intersection angle of model charging center speed and horizontal direction decreased. Practically the decreasing speed of the intersection angle got slower with the value increase of W. Also, with the value increase of W, it was found that the largest vibration velocity increased at first and then decreased, and the main frequency of vibration decreased continually. Besides, the peak strain of free surface increased with the decrease of the distance from it to the exploding source.