微风化花岗岩多向聚能爆破破岩试验研究

Experimental study on rock breaking by multi-direction cumulative blasting of slightly weathered granite

为解决常规装药爆破能量利用率低的问题,设计了一种可以改变能量分配的新型多向聚能管药柱。以某高速公路岩质边坡为对象,通过3组现场爆破试验,获得了多向聚能爆破和常规爆破下微风化花岗岩的裂纹分布、残孔特征以及炸药单耗等参数,对比分析了两种爆破工艺的爆破效果及破岩规律。结果表明:新型多向聚能爆破药柱能在指定方向上产生定向裂纹,增大岩石致裂范围,提高炸药能量在岩石破裂上的分配比例。相比常规爆破,多向聚能爆破炮孔利用率提高了18%,炸药单耗降低了32.5%,岩渣平均块度增大了28%,粉碎区的范围缩小了25.1%,宏观致裂范围扩大了33.3%,证明了多向聚能爆破在破岩效率上要优于常规爆破。

A new type of multi-directional cumulative blasting that changed the energy distribution was designed to solve the problem of low energy utilization of conventional charge blasting.Taking a rock slope of a highway as an object,through three groups of blasting field experiments which were carried out in a rock slope,the parameters such as crack distribution,residual hole characteristics and explosive unit consumption of slightly weathered granite under multi-directional cumulative blasting and conventional blasting were obtained and the blasting effects and the rock breaking laws of the two blasting methods were compared and analyzed.The results show that the new multi-directional cumulative produced directional cracks in specified direction,increasing the range of rock fracture and the distribution of explosive energy in rock fracture.Compared with the conventional blasting,the results show that the new multi-directional cumulative blasting increase 18%the utilization rate of blast hole,reduce 32.5%the unit consumption of explosive,increase 28%the average block size of rock slag,reduce 25.1%the scope of crushing area and expand 33.3%the scope of macro cracking in the crack area,which prove that the multi-directional cumulative blasting is more efficient than conventional blasting.