不同线装药密度对预裂爆破损伤的数值模拟研究

Numerical Modeling Study of Different Linear Charge Density on Pre-split Blasting Damage

利用LS-DYNA数值模拟软件,对不同线装药密度单孔爆破的岩石损伤分布特性进行了对比分析。通过建立三组不同工况条件下(g=300 g/m、400 g/m、500 g/m)的“炸药-切缝管-空气”模型,采用径向不耦合和轴向空气间隔装药结构,分析了切缝药包的定向聚能作用,即岩石损伤范围与切缝管开口方向有着密切联系,非切缝方向比切缝方向的岩石损伤程度更小;线装药密度最优值为400 g/m,线装药密度过小(g=300 g/m),间隔段围岩损伤不贯通,严重影响预裂爆破孔间成缝,线装药密度过大(500 g/m),损伤效果增加不明显,增加施工成本。

LS-DYNA numerical modeling software is used to study of the rock damage distribution features caused by different linear charge density single hole blasting were analyzed and compared.A model that"explosive material-slit tube-air"was established with three different working conditions(g=300 g/m,400 g/m,500 g/m),the radially uncoupled charge structure and axial air space charge structure was adopted to analyze directed concentrating of slit charge,that is rock damage range and slit tube?蒺s opening direction has closed relation,the nonslip direction damage is smaller than the slit direction;the optimal line charge density is 400 g/m,and the interval surrounding rock damage is not penetrating if the linear charge density is too small(g=300g/m),it will seriously impact the seams between holes by pre-split blasting,the damaging effect increasing is not obviously if the line charge density is too large(500g/m),and the construction costs increased.