延期时间对高台阶抛掷爆破效果的影响

为了研究高台阶抛掷爆破合理的延期时间，基于相似材料模型试验，运用有限元软件ANSYS模拟不同排间毫秒延期的抛掷爆破模型.试验和计算结果表明:从增加最远抛距和减少大块率的角度出发，当排间毫秒延期时间小于或等于2 ms时，后排孔爆炸的一部分能量用来给第1排孔爆破的碎块做功，第1排孔碎块的抛距增加，且第1排炮孔的大块率也减少；从有利于改善单元在x、y、z三个方向的应力叠加效果来看，第2排炮孔的延期时间宜定于1.27~2.04 ms之间.由于确定模型尺寸和原型尺寸的几何相似比1:50，故推荐矿山高台阶抛掷爆破的排间延期时间为63.5~102.0 ms. 

High Bench Cast-Blasting Effects Influenced by Delay Time

In order to study the reasonable delay time of high stage throwing blasting, a similar material simulation experiment was conducted, the finite element software ANSYS was used to simulate the throwing blasting model with different millisecond delays. The test and calculation results show that:from the perspective of increasing maximum throwing distance and reducing boulder yield, when the interval between milliseconds is less than or equal to 2 ms, a portion of the energy in the rear row of holes is used to work on the broken pieces of the first row of holes, the pitch of the first row of holes is increased, and boulder yield of the first row of holes is also reduced; from the point of stressing superposition affection which is beneficial to the improvement of the three directions of x, y and z, the delay time of the second successive holes should be 1.27~2.04 ms. Since the geometric similarity ratio of the model size to the prototype size is set at 1:50,it is recommended that the extension time of the row of high-level throwing blasting in mines be 63.5~102.0 ms.