Data-driven evaluation for abnormal vibration of cables during typhoon In-Fa: case study

Abstract

Characteristics of input-output of cables of a long-span cable-stayed bridge in time and frequency domain are studied during the whole process of typhoon In-Fa landfall based on monitoring data. According to the signal characteristics of the time series of wind speed and direction, a new adaptive extraction method of quasi-steady wind speed and direction is proposed fusing wavelet transform and certain-length time series averaging method. Central tendency and fluctuation about the wind speed and direction are summarized. Influences of wind and rainfall environments on the cable abnormal vibration are analyzed. Using the short-time Fourier transform, characteristics of the evolution of vibrational energy in the time-frequency domain for the abnormal vibration of the cable during typhoon are reproduced. The slice analysis of the power spectrum in the frequency domain is performed at the typical moment. The main results demonstrate that extremely high-amplitude non-Gaussian section of abnormal vibrations of cables in this typhoon event is caused by the simultaneous action of wind and rain, the high wind speed or the wind direction with low fluctuation will more likely excite high-amplitude abnormal vibrations of cables, and sufficient damping may help cables suppress the rain-wind-induced high-amplitude vibration.