Soil Expert Witness On Ground Vibrations Part 1

In Numerical methods with experimental soil response in predicting vibrations from dynamic sources, soil expert witness Mark Svinkin writes:

Construction and industrial dynamic sources, such as pile driving and foundations for impact machines, generate elastic waves in soil which may adversely affect surrounding buildings and sensitive instruments (Targets). The effects of these waves range from visible structural damage to serious disturbance of working conditions for sensitive devices and people. Therefore, legitimate concerns frequently arise about possible ground and structure vibrations before the start of construction activities or installation of machine foundations.

Analytical methods (Miller and Pursey, 1954; Broers and Dieterman, 1992; Hanazato and Kishida, 1992; Wolf, 1994) already exist which give accurate results for certain limited cases, but these methods are applicable only to well defined and simple sites like a half-space or horizontally layered media. Indeed, for the prediction of expected vibrations, it is necessary to have information about the actual soil deposit and to choose a proper soil model to compute vibrations. Computed results from the simple models contain valuable data about general tendencies of wave propagation at a site, but cannot take into account spatial variations of soil properties and produce accurate and complete soil vibration records at any point of interest.