Field Testing and Baseline Modeling of the Owensboro Cable-Suspended Bridge--Federal Aid Research Task No. 116

II. Over the past 15 years, the cables of numerous long-span cable-stayed bridges in the U.S. and abroad have experienced large amplitude vibrations leading to troublesome maintenance repairs and costly retrofits. Wind excitation and deck motions are thought to be contributors to the vibrations. Concerns about internal damage and the effects on long-term survivability resulting from these vibrations are open questions. Changes in vibration characteristics, including fundamental frequency and damping, are often used as early indicators of changes in and damage to structures. An efficient data processing techniqu~ developed for use with short ambient tests of bridge stay cables enables the use of quick occasional field tests of cables for monitoring. Such tests can also establish a baseline of the response characteristics, including variability, for future comparisons. III. Objectives The objectives of this research are: (1)- (2)- Conduct ambient vibration field tests of all cables of the Owensboro cable-stayed bridge prior to opening the bridge to traffic, and under extreme seasonal ambient conditions; Extract the dynamic characteristics of all cables from the ambient vibration field test data of the Owensboro cable-stayed bridge; Develop finite element models of the restrained cable sets of the Owensboro cable-stayed bridge and calibrate the finite element models through the results of the ambient vibration testing; and Comprehensively understand the structural dynamic response behavior of the Owensboro cable-stayed bridge cables under service loadings and other dynamic loadings.