INFLUENCE OF GROUND INHOMOGENEITY ON WIND INDUCED GROUND VIBRATIONS

The mechanical behavior of the near surface of the ground (vadose zone, critical zone) is required for many geotechnical applications such as roadway construction, trafficability, foundation design, and agricultural production. The mechanical behavior may also be indirectly related to transport across this critical interface such as; water infiltration and gas flux which are important to hydrological and climate studies. Mechanical sources for investigating near surface of the ground included high frequency electromechanical sources and loudspeakers. We attempt to exploit the pressure fluctuations produced by wind as a source for investigating near surface soil properties. In a previous study, the ground was modeled as an elastic homogenous half space and a prediction model was developed for the wind-induced ground motion. However, ground is a layered or inhomogeneous medium and will have a different response due to the surface pressure. In this presentation, we discuss different kinds of theoretical inhomogeneous grounds and their available analytical responses due to a surface load. Furthermore, we use Comsol-Multiphysics®, a commercial finite element package, to simulate a more realistic ground consisting of a layer over a half-space. A new response function is derived by interpolating the Comsol output to substitute in the wind-ground coupling equations. A comparison between the homogeneous and non-homogeneous ground predictions are used to evaluate the importance of layering on wind-induced ground vibrations.