Stochastic modelling of traffic-induced ground vibration

Abstract In this paper an entirely analytical method of calculating the power spectrum of ground vibration in the vicinity of a busy roadway is presented. It is based on the assumption that vehicles are sufficiently closely spaced that ground vibration can be considered to be a random and statistically stationary process. The assumption is valid at distances away from the road greater than or equal to the mean vehicle spacing. Random process theory is used to obtain expressions for the power spectra of horizontal and vertical vibration when given the power spectrum of road surface roughness, a dynamic vehicle model and a model for vibration transmission through a half-space. A suitable two-axle vehicle model is discussed in an accompanying paper [19], where allowances are made for the statistical variation of vehicle dimensions, weight, suspension characteristics and distribution along the road, and in particular for the effect of wheelbase filtering. Calculated ground-vibration power spectra compare favourably with measured vibration spectra in the vicinity of a busy road near Cambridge.