Exterior view of 600 Montgomery St. (photo by Dan Radulescu)

The objective of this report is to present background information for a study comparing the dynamic characteristics of thirteen buildings obtained using strong-motion and ambient vibration records. Ambient vibration testing is an attractive method of measuring the dynamic characteristics of real buildings, since it does not disrupt building occupants and the necessary equipment is small, light, and very portable. However, because of the low amplitude range of the ambient vibration (10^-5g), dynamic characteristics obtained from ambient vibration should be different from those obtained from strong-motion (>0.1 g) records due to non-linear effects.

The strong motion records were provided by the U.S. Geological Survey (USGS) National Strong-Motion Program (NSMP). At least one strong-motion record is available and has been processed for each building, and as many as sixteen seismic records are available for some buildings. Ambient vibration records were collected using velocimeters (velocity transducers). In order to test the efficiency of the ambient vibration for defining the dynamic parameters of structure, a set of three permanently instrumented buildings has been monitored using ambient vibration.

This report describes (1) the 13 buildings with their permanent instrumentation and locations where ambient data was recorded, (2) the ambient vibration testing, and (3) a description of the strong-motion data sets available for each building. This report contains background information only; no results are presented.