PROPAGATION OF GROUND VIBRATION : A REVIEW

An important environmental aspect of building and facility design is the evaluation of vibration transmitted to the site, through the ground, from external sources. Such external sources may include highway traffic, surface and subsurface railways, and machinery in nearby locations. To properly predict excitation levels at a building due to such sources, one must be able to predict how much vibration, in terms of both levels and spectra, is transmitted through the ground from the source. The problem of predicting the transmission of vibration through the ground is complex [l-8]. The reasons for this complexity include the lack of a comprehensive understanding of soil behavior, the difficulty of determining accurate values of soil properties, and the difficulty of modeling precisely the sources of vibration and the resulting nearand far-field behavior. However, in spite of these and other obstacles, it is possible to make reasonable assessments of ground-transmitted vibration through a judicious use of the empirical and theoretical results that are available. In this paper a review is given of the current state of the art of vibration transmission prediction. It is important to bear in mind that the focus of this paper is not the prediction of levels due to a particular physical source, but rather is it the prediction of the transmission of ground vibration signals from any of a number of sources. The paper is organized as follows. The basic theoretical models for radiation damping (geometrical spreading) and material damping (energy dissipation) are discussed first. Then a precis of current measurement technology and procedure is given. In the next section a review and collation of published measured vibration datais presented, together with empirical attenuation models derived from these data. Finally, a few comments on future research needs are put forward.