Abstract: In the analysis of dynamic soil-structure interaction, viscous artificial boundary condition, viscoelastic artificial boundary condition and far-field artificial boundary are often used to simulate the scattered wave propagating in infinite base. Viscous artificial boundary condition and viscoelastic artificial boundary condition have many advantages such as low computing cost and good accuracy; but amount of labor work of applying boundary elements is heavy; although far-field boundary saves the work of applying boundary elements and can provide highly accurate results; it requires expensive computing cost. In order to address the problem of high labor cost in viscous artificial boundary condition and viscoelastic artificial boundary condition and high computing cost in far-field boundary, an equivalent far-field artificial boundary condition is proposed based on the wave propagating theory and the reflection and transmission principle of wave on the interface of medium by setting a fully-transmitting layer and lowering the speed of wave considerably propagating within it. Then numerical simulations and studies of factors affecting accuracy for equivalent far-field artificial boundary condition are conducted with FEM. Researches show that equivalent far-field artificial boundary can be set up only by setting rational mass and Young’s modulus parameters in transmitting boundary layer to simulate reflected wave propagating in infinite base. Equivalent far-field artificial boundary has many advantages such as good accuracy and efficiency and saving the labor work of applying boundary elements; so it can be applied to the analysis of dynamic soil-structure interaction.

Key words: dynamic, interaction, artificial boundary, viscosity, viscoelasticity, far-field