Response characteristics of stay cable under ambient excitation

The cable vibration on the cable-stayed bridge can easily be excited by wind, combination of wind and rain, traffic loads and so on. To investigate the excitation mechanism and response characteristics of cable vibration under ambient excitation, the field measurements were carried out on the Dongting Lake Bridge, which is the first three towers, pre-stress concrete cable-stay bridge in China mainland. This measurement system consists of anemometers, rain gauge and accelerometers. Based on the measured records and time-frequency analysis technique, the relationships of cable acceleration responses under the vortex shedding and the wind-rain induced vibration versus ambient excitation such as wind and rain are investigated, and the response characteristics of cable vibration, which include the dominant frequency, modal participation, dynamic displacement and tension increment under ambient excitation, also are presented.