Numerical study on intermittent geofoam in-filled trench as vibration barrier considering soil non-linearity and circular dynamic source

Abstract

Open and in-filled trenches are found to be quite impressive vibration screening technique among the researchers. This paper mainly aimed to examine the efficacy of using intermittent expanded polystyrene (EPS) geofoam in-filled trench as the vibration barrier, which is practically a combination of geofoam and air pocket placed alternately throughout the depth of the trench. The vibration screening efficiency of intermittent geofoam in-filled trench is determined under a constant force amplitude-type vertical oscillation of a machine resting on a circular embedded foundation. The effect of various parameters such as depth, width, inclination, and location of trench, excitation frequency of the source, and density of geofoam on the screening efficiency of geofoam in-filled is explored using 2D finite element method. The soil is modelled as non-linear elastic under the excitation of moderately high-speed machine. In the presence of machine-induced vibration, the vertical displacement at different locations along the ground surface is captured to determine the amplitude reduction ratio (ARR), which helps in assessing the efficiency of the vibration screening technique.