最小抵抗线对台阶模型爆破效果影响研究

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

为揭示最小抵抗线(W)对台阶模型爆破效果的影响,利用相似准则原理加工混凝土台阶模型进行爆破试验,并采用高速摄影系统、瞬态信号测量仪以及超动态应变测试仪等对爆破效果进行监测分析,得到结果如下:爆堆质量及最大块度随着W的增大而增大;随着W的增加自由面初速度减小,模型装药中心点合速度与水平方向夹角逐渐减小,且W越大夹角减小越缓慢;自由面上的峰值应变随到爆源距离的减小而增大;随着W的增大最大振动速度会先增加后减小,爆破振动主频则呈现逐渐降低的趋势.

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.