Soil Structure Interaction Simulation & Analysis

Concrete dams, nuclear power plants, high-rise buildings and bridges are massive enough that their vibration due to earthquake excitation affects the motion of the soil or rock supporting them, which in turn further affects the motion of the structure itself. This interaction between the structure and the soil needs to be modeled accurately in order to design earthquake-resistant structures and to correctly evaluate the earthquake safety of existing structures.

LS-DYNA’s novel method for soil-structure interaction analysis applies the earthquake forces in an efficient, rational manner and models the unbounded domain accurately at low computational cost, given a free-field ground motion characterizing an earthquake. It uses the effective seismic input method to incorporate the earthquake forces into the soil-structure interaction model, using only the free-field ground motion at the soil-structure interaction interface, and not requiring any deconvolution down to depth, unlike older methods of earthquake input. The unbounded domain is modeled using perfectly matched layers, which absorb the outward-propagating waves almost perfectly with only a slight increase in cost from the classical Lysmer dashpot boundaries.