On forced vibration testing for quantifying damage in building structures

Abstract

The focus of this study is on the use of forced vibration testing and of finite element model updating techniques to quantify existing damage in a four-story reinforced concrete structure. The specimen structure is the so-called Four Seasons Building, located in Sherman Oaks, California. It was damaged from shaking during the 1994 Northridge Earthquake, and is currently slated for demolition. Using the nees@UCLA mobile testing equipment, we have recorded floor accelerations as well as strains at select locations during forced vibration tests with linear and eccentric mass shakers. The data were used to update a finite element model of the structure. The updated model appears to correlate well with the observed distribution of damage throughout the building, and enables to quantify its severity.