单基发射药孤石爆破特性实验研究

Experimental Study on Boulder Blasting Characteristics of Single-base Gun Propellant

为研究单基发射药孤石爆破特性,利用直径和高度均为50 cm的水泥砂浆试块模拟孤石,开展了0.05~0.25 kg/m^(3)单耗的单基发射药和乳化炸药孤石爆破实验,统计并分析了单基发射药和乳化炸药爆破试块的块度分布、破碎能及能量利用率随单耗的变化规律。结果表明:乳化炸药爆破孤石的最大块度随单耗的增加,但能量利用率变化不大。结合高速摄影观察对比单基发射药和乳化炸药爆破孤石的表面裂纹分布与扩展结果,发现单基发射药破岩模式与乳化炸药存在显著差异,其破岩模式是通过在炮孔内快速燃烧产生的高压气体使试块发生轴向和环向的拉伸破坏,而当试块完全开裂后剩余的发射药不再提供破岩能量。

To study the boulder-blasting characteristics of single-base gun propellant,boulder blasting experiments of the single-base gun propellant and emulsion explosive were carried out,cement mortar blocks with 50 cm in diameter and height were employed to simulate the rock boulders,and powder factor was 0.05~0.25 kg/m 3.The variation of fragmentation distribution,crushing energy,and energy efficiency with powder factor of boulder blasting experiments were analyzed.The results showed the boulder-blasting maximum fragmentation size decreased with the increasing powder factor,the energy efficiency barely changed with powder factor.The surface crack distribution and propagation of boulder blasting with single-base gun propellant and emulsion explosive were observed through high-speed photography,which revealed that the rock-breaking mode of single-base gun propellant was significantly different from that of emulsion explosive.The gas pressure raised rapidly with the combustion of single-base gun propellant in the borehole,which lead to the axial and circumferential tensile failure of the boulder.When the boulder was completely broken,the remaining propellant will no longer provide rock-breaking energy.