解耦爆炸中震源位置偏离对激发S波的影响

The effects of offset of explosion on generation of shear waves from decoupled explosion in the cavity

对球形空腔偏心解耦爆炸进行了数值模拟,得到了不同方向和不同爆心距节点的S波和P波速度曲线以及岩石单元中拉伸应力的传播过程。结果表明:空腔偏心解耦爆炸激发的S波具有方向性,S波幅值与对应P波幅值相当,激发S波的物理机制是振荡的拉伸应力,它等效于偶极子震源。

Numerical simulations are processed on decoupled explosion while the explosion is offset from the center of spherical cavity. The nodesr velocity wave-forms of P waves and S waves in different directions and at different distances are gotten as well as the promulgation of tension stress wave in elements of rock. The results indicate that the S waves generated from the decoupled explosion are directional, and are comparable in amplitude to the P waves of the same place, and also indicate that physical mechanism for generation of shear waves from decoupled explosion in spherical cavity is the vibration of tension stress waves. The vibration of tension stress waves can equivalent to a dipole source acting in the direction of the offset.