基于变直径掏槽孔爆破的数值模拟

在中小断面的巷道爆破开挖中,因岩石的夹制作用、断面狭窄等因素影响了巷道的爆破效果和限制了掘进进尺,导致工作效率低下,工程成本较高。为此提出了基于变直径掏槽孔爆破技术,利用AUTODYN程序建立了二维数值模型,通过二维数值模拟使爆破过程动力计算精细化,得出了不同规格变直径掏槽孔的爆破应力传播规律、岩石表面单元应力变化特点和变直径孔对岩石内部的爆炸能量具有约束能力的结论,验证了对变直径掏槽孔的爆破作用机理分析的正确性。并通过比较分析认为,底部直径越大、上部直径越小的变直径掏槽孔对岩石的破碎效果越好。

Numerical simulation for cut blasting technology based on variable-diameter holes

In the process of tunnel excavation on middle and small-sized tunnel, as rock clamping, the narrow of drift section and other factors that have influenced blasting effect and limited circulation footage, it results in less work efficiency and higher engineering cost. By studied, technology of cut blasting based on variable-diameter holes is put forward firstly. 2 D models is established respectively by virtue of AUTODYN. 2 D models can make dynamic calculation finer in blasting process. We concluded propagation rule of the explosion stress wave,the changing characteristic of element stress on the rock surface and the result that variable-diameter holes restrain explosive energy in rock, and prove blasting mechanism is validity. Through contrasting and analyzing, as the larger is the bottom diameter, the smaller is the upper diameter,fragmentation effect will get better.