Abstract: Ground motion plays an important role in the estimation of dynamic loading for ground support design in burst-prone underground mines. A semi-empirical scaling law is often used for peak particle velocity (PPV) estimation; however, this method does not account the influence of geology and excavation effect on the ground motion in the dynamic support design. For better understanding the excavation effect of boundary distribution in the underground on the ground, the author puts forward a coupled numerical simulation method for non-linear velocity model and FLAC/ SPECFEM2D. Aiming at the high quality and fair quality rock masses, the numerical analysis of the ground motion distribution of an underground stope is carried out. It is found that different velocity models influence ground motion distributions near excavation boundaries greatly. Considering the effects of confining pressure and excavation on the nonuniform velocity model can better simulate the distribution of ground motion near the underground excavation boundary, amplification effect at excavation surface is captured, which agrees well with underground field observation results. Compared with the high quality surrounding rock mass, when the simulated excavation rock is fair quality rock mass, the excavation boundary of the stope has stronger ground motion and wider seismic response.

Key words: ground motion, numerical simulation, wave field simulation, PPV