Field test to determine frequencies of bridge stay cables

The Fred Hartman Bridge experienced large-amplitude rain and wind-induced vibrations, which led to modeling efforts. A field test was conducted to determine the fundamental frequency of each of the 192 cables. This article presents the field test, analysis of data, and results. A comparison of results for eight sets of nominally identical cables shows small fundamental frequency differences in sets of long string-like cables, but large frequency differences in sets of short beam-like cables. Therefore, different test and analysis approaches are needed for long and short stay cables.