Probability Analysis of Rain-Wind Induced Vibration of Stay Cables Due to Tropical Cyclone

The rainy and windy weather conditions during the passage of tropical cyclone (TC) usually cause large-amplitude rain-wind induced vibration (RWIV) of stay cables in bridges, threatening the fatigue life of stay cables and even the safety of bridge structures. In this study, the probability analysis of RWIV of stay cables under TC-induced wind and rainfall environment is performed using both wind tunnel test and numerical simulation techniques. RWIV amplitudes associated with various combinations of wind speed and rainfall rate are obtained by wind tunnel test on a prototypic sectional cable model. Surrogate models including polynomial and Kriging methods are introduced to fit the experiment results, allowing for the construction of three-dimensional surface representing RWIV amplitude or the capacity of the stay cable. A case study is performed to the Jintang Cable-stayed Bridge located at the southeast coast of China. Ten-thousand-year synthetic TC tracks around the bridge site are then generated by Monte Carlo technique. Subsequently, wind speeds and rainfall rates at the bridge site for every storm are calculated using the three-dimensional TC wind field model and HuRRDE (Hurricane Rainfall Rate and Distribution Estimator) model, achieving the joint probability distribution of wind speed, wind direction and rainfall rate. The occurrence probabilities of various RWIV amplitudes during TC process are finally calculated to conduct the probability analysis. The framework and results in this study can be utilized as a guideline and reference for the design and early warning of stay cables against RWIV.