Simplified design for vibration screening by open and in-filled trenches

Rectangular open or in-filled trenches (wave barriers) are often used in engineering practice to reduce the ground vibrations caused by propagating surface (Rayleigh) waves of relatively small wavelengths. This paper presents simple design expressions for estimating the vibration screening effectiveness of rectangular wave barriers in homogeneous soil deposits. The design formulas are developed by conducting an extensive numerical investigation on the influence of various geometrical and material parameters on the vibration screening effectiveness of the barriers. An advanced direct Boundary Element Method (BEM) incorporating higher-order isoparametric elements and a sophisticated self-adaptive numerical integration scheme is used for this study. Dimensionless parameters that govern a barrier's performance are then identified, and models are developed taking these parameters into account in a simplified way. Through some comparisons with results from the rigorous BEM code and available experimental data, the applicability of the model is demonstrated. Some layered soil cases are also studied, and the important effects of layering on the performance of a trench as a wave barrier are presented.