AUTOMATION OF MODAL PROPERTY EXTRACTION FOR A PERMANENTLY INSTRUMENTED HIGHWAY BRIDGE

摘要

Automation of modal property extraction from large sets of periodically collected global response data is a key component in permanent structural health monitoring systems that rely on changes in the dynamic properties of the structural system to detect damage or deterioration. Point-in-time datasets are most easily collected using output-only methods. The output-only methods in common use in the research literature include, transmissibility functions, FDD, SSI, and RD/ITD, all of which rely on unmeasured excitation from ambient environmental sources and passing traffic to generate response data. Most research efforts using these methods focus on modal property extraction and the corresponding systems identification of the existing structural system. To extend these methods to permanently monitored structures it is necessary to automate the point-in-time data extraction process for individual structures. This paper presents the results of such an effort for a new permanently instrumented two-span reinforced concrete highway bridge. This structure and a geometrically similar carbon-fiber reinforced two-span structure were permanently instrumented to monitor changes in structural condition.