抛掷爆破混凝土介质飞散行为研究

Ejection Behavior of Concrete Materials Under Cast Blasting

针对内爆炸载荷作用下混凝土介质的抛掷问题,采用量纲分析与数值模拟相结合的方法,对抛掷爆破条件下混凝土介质飞散行为进行了研究.通过量纲分析得到了以装药量与埋深为自变量的关于平均抛掷速度的函数表达式.基于爆坑内混凝土介质抛掷速度的分布规律,定义了爆破后混凝土介质的平均抛掷速度.基于AUTODYN-2D数值模拟结果数据,拟合得到了用于估算平均抛掷速度的工程表达式.为了验证该公式的适用性,对其进行了显著性检验,结果表明,该公式在置信水平为0.99条件下是显著的,说明其精度较高,具有较好的适用性.

The ejection velocity of fragmented concrete mass formed in the cast blasting was studied with the method of dimensional analysis and numerical simulation. The influence factors of casting velocity was analyzed, and function expression of casting velocity with charge mass and depth of burial as independent variable was derived by dimensional analysis. Average ejection velocity was defined according to the distribution of the fragmented concrete mass. Ejection velocity varies from different charge mass and depth of burial was simulated by SPH using AUTODYN-2 code. With the simulation results, the semi-empirical formula for ejection velocity was fitted. The significance testing for the semi-empirical formula was conducted. And the results show that the confidence level is more than 0.99, and the accuracy of this formula fully meet the engineering requirements.