Gary M. Glickman; James T. Nelson, PhD, PE; Richard A. Carman, PhD, PE
Wilson Ihrig, CA

Abstract

Detailed prediction of groundborne noise and vibration from proposed rail transportation
systems involves characterization of ground vibration propagation characteristics specific to
sites with sensitive land uses along a project alignment. The methodology widely used in the
United States relies on transfer mobility measurements performed at a limited set of
locations, the results of which are typically used to characterize an entire corridor. Numerical
and analytical models for predicting ground response can be used to interpret data, address
limitations of field measurements, and refine predictions at locations where only soil strata
data are available. Finite Element Analysis can be used to model the vibration response of
the ground as well as that of building foundations, tunnels, and other structures that often
add complexity to the prediction problem. In this paper, we examine the ground surface
response to an impulsive force via a transient response analysis performed using Finite
Element Analysis to obtain one-third octave band transfer mobility functions. Analytical and
numerical model results for a buried pulse in rock are presented and show general
agreement with empirical data. Techniques used to address some of the limitations
associated with modeling elastic wave propagation in semi-infinite media are discussed.