工程爆破问题数值模拟研究

NUMERICAL SIMULATION OF ENGINEERING BLAST

工程爆破方法在开矿、筑坝、修路和凿洞中得到了广泛使用,经验和分析表明,当炸药埋深超过40米时,重力对爆破抛掷现象有明显影响,但目前缺乏系境研究。本文提出了一个用于爆破作用下的岩体本构数学模型,并用二维轴对称数值计算方法对有重力影响的工程爆破问题初始阶段进行了详细研究,计算结果包括爆炸应力波的传播规律,岩体的加速与破坏过程,空腔与地表面的运动规律,抛掷区的形成与划定,能量分配关系等,结果表明:重力对爆炸波的传播基本无影响,重力仅影响抛掷区的大小和抛掷区动能占总爆炸能的比例。

Engineering blast has been applied widely in different fields,for example,mining, dam construction, road and tunnel engineering, etc. By experience and analysis, when depth of burst is greater than 40 meter,the gravity effeet can not be negligible. But the systemic investigation on it is very limited. A mathematical model of rock mass constitution under engineering blast condition is suggested in this paper. And a numerical simulation of engineering blast two dimensional cylindrical symmetry has been used to study the gravity effect. The primary stage of engineering blast was investigated in detail. The main results introduced here consist of stress wave propagation caused by explosion,the acceleration and deformation process of rock mass,cavity development, ground surface movement,formation and definition of ejection zone,energy assign, etc. It was shown that gravity effect on blast wave propagation could be negligible. The gravity primaryly effect the scale of ejection zone and the ratio of dynamic energy of ejection zone to the total explosion energy.