耦合装药特性对深孔预裂爆破应力波能量衰减的影响

针对利用深孔预裂爆破技术对低透气性煤层进行强化增透过程中爆生应力波能量弱、衰减快、信噪比低的现状,对爆破孔装药结构提出了改进方案,建立了耦合装药对爆破孔孔壁透射波能量和爆炸载荷影响特性的数值计算模型,利用Matlab编程技术对此数值计算模型进行了计算并获得解析解。在淮南矿业集团顾桥矿进行了爆生应力波能量受耦合装药系数ξ变化的影响特性的现场实验,对基于功率谱的能量分析法进行了改进,并利用此分析法对实验数据进行分析。数值计算和现场实验均表明:随ξ的增大应力波总能量反而减小;当ξ为1.5时,应力波信号在10~50 Hz频段的能量最强,且信噪比也最高。因而在爆破增透实施过程中应将耦合装药系数ξ设计为1.5左右,从而获得最佳的增透半径和增透效果。

Impact of coupling charge properties on energy attenuation of stress waves of deep-hole presplit blast

Aimed at background of weak energy and low SNR of stress waves generated by deep-hole presplit blast in coal-bed，a reasonable improvement solution was put forward.A numerical model for calculating explosive load on explosive drilling-hole’s wall and transmitted wave energy was built under the condition of coupling charge and non-coupling charge，and analytical solution was acquired by programming code in Matlab software.Meanwhile，on-site experiments were carried out to acquire the impact of coupling charge coefficient ξ for the energy of stress waves generated by blast in Pansan Coal Mine of Huainan Coal Group，and improved energy analysis method based on power spectrum was used to analyze experimental data.Both theoretical calculations and on-site experiments show that：the total energy of stress waves decrease as the increase of ξ; when ξ=1.5，stress waves have strongest low frequency energy and highest SNR in the frequency range of 10-50 Hz.so，in the practice of promoting permeability using deep-hole presplit blast，coupling charge coefficient ξ should be designed as 1.5，and this can acquire the best permeability promoting radius and effect.