Modal Testing of Non-structural Components for Seismic Risk Assessment

Abstract

The continuing operation of non-structural components after an earthquake is of utmost importance for essential facilities such as hospitals, power generation plants, emergency operations centers and nuclear power plants. Failure of non-structural components becomes a hazard to the facility occupants and could disrupt the required operations of the facility after an earthquake event. Modal testing was implemented at a hospital to determine the modal parameters of non-structural components in hospitals located in Vancouver, British Columbia. A database with the modal parameters of these components was created which also included details pertaining to the type of restraint or isolation system. The testing program focused on operational components that perform essential services in these critical buildings such as plumbing, mechanical, and electrical system components. The tests were performed using excitations from ambient vibration and impact test. The tests were done using tri-axial accelerometers, their application was validated by comparing a modal model from accelerometer measurements to a model from laser vibrometer measurements. The information contained in the database will be used to develop methods for assessing seismic risk of non-structural components in essential facilities, assessment which can be used to mitigate risks and improve seismic performance.