Abstract: At present, most of the ground motion inputs for layered foundation simulations consider only the influence of different materials on wave speed, ignoring the refraction and reflection of waves at the interfaces of different media. To improve the simulations of elastic wave propagation in layered foundation, this study derives an equivalent load calculation formula considering the media interface refraction and reflection based on the wave theory, and constructs an artificial viscous-spring boundary model of layered foundation. We verify the model through example analyses. The results show this seismic input method can better meet the accuracy requirements of anti-seismic engineering, and is effective and practical for layered foundation design.

Key words: layered foundation, ground motion input, artificial viscoelastic boundary, amplitude ratio, secondary development of ABAQUS