Statistical Models of a Concrete Bridge: Changes in Modal Parameters Due to Temperature

Abstract

Vibration-based structural health monitoring (SHM) has become a tool in evaluating the condition of civil structures. For bridge structures, vibration-based SHM systems may use the dynamic response of a bridge to measure modal parameters. A change in a structure's modal parameters may indicate damage or other changes to the structural system. These same modal parameters are also sensitive to environmental conditions, primarily temperature. Statistical models have been utilized to differentiate the modal parameter changes caused by temperature and those caused by physical changes. Statistical models also help describe the relationship between modal parameters and environmental conditions. The Lambert Road Bridge is a concrete integral abutment bridge located in California on Interstate 5 (I-5), south of Sacramento. In this study, a SHM system installed on the Lambert Road Bridge was utilized to monitor the bridge's modal parameters and temperatures. The measurements from the SHM system were used to create multiple linear regression models that helped describe the relationship between the structure's modal parameters and temperatures.