Analytical Modeling of Traffic-Induced Ground Vibrations

Abstract

This paper presents an analytical method to estimate the power spectral densities (PSDs) of traffic-induced ground vibrations. Random vibration method is used in the analysis. Ground vibrations are assumed to consist of primarily Rayleigh waves induced by moving forces and propagating along the surface of an elastic homogeneous half-space. The moving forces are generated by vehicles traveling on rough road surfaces. Using a single-axle two-degrees-of-freedom vehicle model and the theoretical solution derived by Lamb for wave propagation on the surface of an elastic half-space, a closed-form solution is derived for ground vibration PSDs at various locations from the roads. To validate the analytical formulas, vertical accelerations at ground surface induced by moving vehicles at three sites with different soil conditions are measured. The surface roughness on adjacent roads of the three sites are also measured to minimize the uncertainties involved in analytical calculations. The measured ground vibration PSDs are compared with the theoretical results and close agreements are observed.