露天深孔台阶爆破参数优化设计

Parameters Optimized Design of Open Deep-Hole Bench Surface Blasting

为解决实际工况中易出现的大块率高和根底较多的问题,基于宽孔距、小排距的爆破机理选取新的孔距a1=13m,排距b1=4m,利用ANSYS LS-DYNA软件对改良布孔前后的爆破过程进行了模拟分析,并研究了孔中、孔底和二者同时起爆共三种起爆方式下岩体不同部位的应力变化.模拟结果表明:采用新的孔网参数可以加强爆轰产物对岩体的破坏作用;针对顶部易出现大块岩体问题,采用孔底起爆具有良好效果;针对底部易出现较多岩体的问题,宜采取孔中、孔底同时起爆的方式.

Toe rock and boulders are important evaluation indicators of open-pit mine blasting.Based on the rock blasting mechanism of wide space and small row spacing,the new holes distance and rows distance were selected as 13 mand 4mrespectively.The blasting process with new design was simulated by LS-DYNA,so as the three different initiation ways,the stress changes at various locations of rock were analyzed.The influences of the optimization on the stress of places with high boulder rate was simulated and studied.The simulation results show that the new pattern parameters can reinforce the destructive action of explosion products to the break of rock.Detonated at hole-bottom could lead a better effect when the top region of rock was generated more easily,and detonated at hole-bottom and holecenter synchronously could be a better method when the toe rocks were appeared at bottom generally.