Full-scale measurements to investigate rain-wind induced cable-stay vibration and its mitigation

Large-amplitude vibrations are known to occur in the main stays of cable-stayed bridges in the presence of rain and wind. Although this problem first surfaced in many bridges around the world in the mid-1980s, it was not until 1996 when the Texas Department of Transportation began to investigate this problem in the United States. Both wind-tunnel and full-scale tests were conducted simultaneously to better understand this phenomenon and devise mitigation methods to reduce the vibrations. Full-scale tests were conducted on four cable stays of the Veterans' Memorial Bridge near Port Arthur, Tex., over a period of three years. This paper presents observations from selected full-scale data and compares them to wind-tunnel test results as well as results found in past literature. Some observations regarding assessment of a distributed passive mitigation device that was installed on one of the cable stays in the field to control vibrations in the presence of rain and wind are also presented. Wind-tunnel tests show that this device is very effective. Limited data collected from the field after the installation of the device gives some evidence of its effectiveness in reducing the vibrations.