Practical characterization of transient ground-borne vibrations in civil and geotechnical engineering problems is often a difficult and frustrating task. Some modem engineering seismographs now routinely permit the collection of histogram-type data where the peak vibration for a pre-set time interval can be measured and stored for significant time periods. Such data is amenable to analysis utilizing concepts of fractal geometry and self-ordered criticality. Resulting data trends tend to follow power-law relationships that plot as essentially straight lines in log-log space. This application is similar to the Gutenberg-Richter relationship for earthquakes where the relationship between magnitude and frequency is fractal. However, the largest vibrations appear to follow another power-law trend appropriate to characterizing extreme events. Four cases of monitoring apparently random transient ground-borne vibrations are examined using this power-law approach: traffic induced vibrations near the curb of an urban arterial street, an unidentified vibration interfering with a precision machining operation, vibrations induced by vacationing children using the front door of a residence, and vibrations induced by water transport in a pipeline. All cases could be characterized by this approach
