Mechanisms of S wave induced during rock fragmentation by blasting are concluded and analyzed as follows. The short column charge
cracking and breakage of rock mass around blast hole and deviation of charge away from the centre of spherical or cylindrical cavities can induce S wave. The interaction of P wave with rock interfaces during propagation can produce secondary S waves (transmitted and reflected S waves). On the basis of this
some proposals on how to choose the numerical method and calculation model during blasting vibration simulation are put forward so as to reflect the mechanisms of induced S waves.