Application of Orthogonal Decomposition Approaches to Long-Term Monitoring of Infrastructure Systems

This paper focuses on the areas of data-management, data quality control, and feature-extraction of meaningful parameters to describe large-scale infrastructure systems' response to ambient excitation in the context of Structural Health Monitoring. Recordings from the monitoring system installed on the Vincent Thomas Bridge (VTB) in San Pedro, California form the database of the proposed data-management and archiving methodology. The data processing methodology for the VTB is based on the calculation of the sensor array acceleration covariance matrices for every hour of available data, and the subsequent orthogonal decomposition of the covariance matrices. It is shown that the computed statistical distributions of the bridge response can provide a quantitative baseline through which to facilitate the early detection of any anomalies indicative of a possible structural deterioration due to either fatigue (service loads), or extreme loading events, i.e., earthquake, man-made, or any other natural hazard.