地下核爆地表振动数值模拟

Numerical Simulation of Surface Vibration of Underground Nuclear Explosion

为研究地下核爆炸产生近场次声波的机理,采用爆源等效模型对封闭式地下核爆炸的发展过程进行了数值模拟计算。模拟结果表明:荷载作用时间对于爆炸产生的地表加速度、岩石中压力和质点速度等物理量有较大的影响,但其波形变化趋势基本一致,求得的爆炸空腔周围岩石的质点速度和应力变化与经验公式符合较好;该计算方法能够较好地描述地下核爆炸的爆炸压力波的发展过程,计算得到了距离爆炸投影点不N距离处的地面加速度值,避免了对核爆炸周围岩石介质的非弹性变形区的计算,大大简化了计算过程。

In order to study the mechanism of near-field infrasound produced by underground nuclear explosion,the development process of closed underground nuclear explosion was numerically simulated by using the equivalent source model.The simulation results show that the load acting time has a great influence on the surface acceleration,the pressure and the particle velocity in the rock caused by the explosion,but the wave shape change trend is basically the same.The calculated particle velocity,stress change of the rock around the explosion cavity are consistent with the empirical formula well.The calculation method can describe the development process of pressure wave of underground nuclear explosion,calculate the ground acceleration at different distances of explosion projection points,and avoid the calculation of inelastic deformation area of rock around nuclear explosion.