The Wind Characteristics Of Typhoons In Qiongzhou Strait And Short-term Wind Speed Forecasting

Typhoons are one of the most common natural disasters.Typhoons usually make people’s life and traveling in trouble.More seriously,it causes major accidents such as the collapse of houses and bridges,leading to serious economic losses.Typhoons threaten the safety of the structural of large-span bridges as its destructive effect.The Qiongzhou Strait region of China experiences the occurrence of typhoons each year.Wind loads become one of the key controlling loads that should be considered in the design of long-span bridges of the areas.To reduce the impact of typhoons during the whole lifetime of bridges,it is necessary to investigate the characteristics of the wind fields of Qiongzhou Strait to provide base data for wind resistance-design of bridge.Therefore,in this paper,the analysis of the wind field characteristics of Typhoon "Ramason" and "Butterfly" are conducted obtained from the field measurements of the Qiongzhou Strait observation tower.It focus on the mean and fluctuating wind characteristics of the typhoon base on the MATLAB programming platform.In addition,the research of the wind speed forecast are carried out.And a new hybrid wind speed forecast method is proposed based on the model decomposition technique and ARIMA-SVM.Besides,the prediction performance is verified.The results show that new method can significantly improve the prediction performance of the single prediction model.The prediction accuracy of the new model meet the needs of engineering application.The model can be used to predict the wind speed and sent out an early warning of overruns to avoid accidents of vehicles driving on the bridge caused by crosswind.The results of this paper can provide safety reference for the bridges in the design and operation phases.The research content and results of this paper are as follows.(1)In this paper,in view of different wind field environments and research objects,the wind characteristics of different sites such as mountain winds,high-rising and low buildings and coastal areas are introduced based on based on field measurements and wind tunnel tests.It is necessary to conduct the research of the wind characteristics and wind speed forecasting of the Qiongzhou Strait area.(2)The sources of the research data and the theoretical knowledge used in the study are described in detail.(3)The wind field characteristics of typhoons "Ramason" and "Butterfly" are analyzed in detail based on the non-stationary model.It also investigates the correlation of the wind parameters,and the corresponding fitting formula and fitting parameters are obtained by fitting analysis.(4)A hybrid empirical modal decomposition and ARIMA-SVM wind speed forecasting model are proposed,and the prediction performance of the model are checked utilization of the measured wind data of typhoons "Ramason" and "Butterfly".The results show that the new model can improve the wind speed prediction accuracy and has better prediction performance.