矿用条形药包轴向爆轰波碰撞聚能特性研究

针对矿用条形药包爆破坚硬岩石时,常出现大块率高、留有爆破根底的情况,提出了一种改变条形药包爆轰压力分布的双线性对称起爆技术。采用数值模拟与标准试验相结合的方法,分析了双线性对称起爆下条形药包轴向爆轰波的传播特性。研究表明:采用双线性对称起爆时,爆轰波依次产生正反射、斜反射和马赫反射现象,爆轰压力可达到中心点起爆时稳定爆轰压力的1.75倍以上;在药卷中心与起爆点连线相垂直的截面边缘上,爆轰压力值可达到稳定爆轰压力的4.09倍以上;在32～80 mm药卷直径范围内,爆轰波碰撞聚能效果随着药卷直径的增大而增大。与铅壔试验结果对比表明:采用双线性对称起爆时,炸药做功能力相较于中心点起爆方式可提升14.5%(铅壔试验)和17.1%(数值模拟)。研究结果对于爆轰波碰撞聚能机理研究有一定的参考意义,可为降低爆破根底和提升炸药能量利用率提供新思路。

Study on Propagation Characteristics of Axial Detonation Wave of Mining Linear Charges

A bilinear symmetrical initiation technique is proposed to solve the problem of high bulk rate and bedrock when hard rock blasting.In this paper,the propagation characteristics of axial detonation wave of cylindrical charge under bilinear symmetric initiation are analyzed by combining numerical simulation with the standard test.The numerical simulation results show that the detonation wave produces positive reflection,oblique reflection,and Mach reflection in sequence when the bilinear symmetric initiation is adopted,which can effectively increase the detonation pressure inside the explosive.The detonation pressure can reach more than 1.75 times of the stable detonation pressure at the central point of initiation.Compared with the central point initiation,the detonation pressure value is more than 4.09 times of the stable detonation pressure on the cross section edge perpendicular to the line between the center of the charge column and the initiation point.In the range of 32~80 mm charge diameter,the cumulative effect of detonation collision increases with the increase of the charge diameter.Compared with the lead block test results,the power capacity of the explosive can be increased by 14.5% (lead block test) and 17.1% (numerical simulation) when using the bilinear symmetric initiation method compared with the central point initiation method.The research results are of certain significance to study the mechanism of detonation collision energy accumulation,and provide a new method of reducing the blasting bedrock and improving the energy utilization rate of explosives.