Scattering of Seismic Waves by Shallow Building Foundations Using High-Order FEM

The United States Army is continuously improving upon its situational awareness in all operational environments. To extend the usefulness of seismic sensors to urban environments, we first need to understand the scattering of seismic waves by shallow foundations. Our objective is to use three-dimensional, high performance computations to characterize this scattering at fairly low propagation frequencies. The results include an h-(mesh size) and p-(element order interpolation) refinement study, and wave-field measures of constructive and destructive interference (scattering) at low frequencies for an urban model that includes typical shallow foundations. The interference measures demonstrate the ability of the code STARS3D to quantify seismic scattering from urban structures. We conclude that shallow building foundations do impact seismic wave propagation in urban environment.