岩体爆破综合实验研究系统及其应用

为定量分析研究毫秒延时爆破破岩过程特征物理量分布演化机制,进一步优选爆破参数、完善毫秒延时破岩机理,进行了室内毫秒延时台阶爆破相似模型实验。应用高速摄影机和超动态应变仪建立综合实验研究系统,对毫秒延时爆破进行动态实时监测,得到台阶自由面处裂纹扩展规律和延时时间对边坡表面应力峰值及内部应力场叠加的影响程度。结果表明,确保后序药包起爆时已形成新自由面的最小临界延时为9 ms;设计延时为15 ms或25 ms时,可降低对边坡表面应变峰值影响程度;为促进相邻炮孔爆炸应力波充分叠加、增强岩体破碎效果,孔间延时最大临界值为15 ms。综合考虑坡体应力状态及台阶爆破效果双重因素,实验条件下最优孔间延时为15 ms。

A Comprehensive Experimental Research System for Rock Blasting and Its Application

In order to do quantitative analysis for distribution evolution mechanism of characteristic physics quantities in millisecond delay blasting, so as to further optimize the blasting parameters and perfect the rock fragmentation mechanism of millisecond delay blasting, an indoor millisecond delay blasting simulation model test was designed and carried out. An integrated experimental system consisting of high-speed camera and ultra-dynamic strain gauge was used to monitor millisecond delay blasting dynamically. The crack propagation law of bench free surface and impact of different delay time on the peak stress or superposition of internal stress were analyzed. Results show that with the minimum critical delay of 9 ms for providing free face, the impact on strain peaks can be reduced with delay time designed to be 15 ms or 25 ms. In order to promote the full superposition of explosive stress wave and enhance the effect of rock broken, the maximum critical value of the delay time is 15 ms. Taken factors of slope stress state and blasting effect into consideration, the optimal delay time between holes is set to be 15 ms in the experiment.