中部空气间隔装药结构不耦合状态光面爆破效果研究

Research on Smooth Blasting with Decoupled Explosive Charge in a Mid Column Air Deck System

分析了5种中部空气间隔装药不耦合状态的光爆效果,运用ANSYS/LS-DYNA软件针对5种不同的不耦合系数分别建立了5种不同空气柱长度的数值模型,比较相邻周边孔1/2孔距及孔壁所选单元的有效应力时程曲线及有效应力峰值随不耦合系数变化的规律,结果表明,有效应力随轴向不耦合系数增大而减小。从减小炸药段附近单元有效应力以及保证空气柱中部裂缝贯通的角度出发,于本文模型的地质条件下较优的轴向不耦合系数为3.5～4.5。

An analysis for smooth blasting with decoupled explosive charges by using an air decking system with 5 different air column lengths was presented. Numerical models with 5 kinds of air column lengths and different decoupling coefficient were established by using ANSYS/ LS.DYNA software. Effective stress vs time curves for the section of neighboring borehole with 1/2 spacing, as well as for the borehole walls were plotted and compared, and the relationship between the effective stress peak and decoupling coefficient was also analyzed. Results showed that the effective stress was decreased with the increasing of axial decoupling coefficient. Based on the consideration of reducing the effective stress near the explosive charge section, as well as for ensuring the blast.induced cracks developed through the middle part of air column, the optimal axial decoupling coefficient for the established model in this paper was determined to be around 3.5~4.5.