Dynamic Response Analysis Of Cable-stayed Sea-crossing Bridge Under The Combined Action Of Relevant Wind And Wave

The sea-crossing bridge is a transportation link between continents,countries,mainland and islands.Cable-stayed sea-crossing bridge is a main structure form of sea-crossing bridge,which has greater spanning capacity.Sea-crossing bridges will be subjected to wind,wave,current and other marine environmental loads during the process of construction and use.Especially,sea-crossing cable-stayed bridges have the characteristics of high tower and large span,and the structural dynamic response is remarkable under the action of wind,wave and current.There is a certain correlation between ocean wind and wave,which affects the synchronization of wind and wave loads and the dynamic response of structures.At present,the research on how the correlation between wind and wave affects the dynamic response of structures has not been thoroughly studied,but the structural response is the key to structural safety design.Therefore,the study on the influence of wind-wave correlation on the structural dynamic response of cable-stayed bridge will provide an important basis for the consideration of wind-wave correlation in the design of sea-crossing bridges.Therefore,in this paper,the numerical simulation method is used to analyze the dynamic response of cable-stayed sea-crossing bridge under the combined action of wind and wave.The main research contents are as follows:Firstly,the descriptive functions of wind and wave characteristics,such as average wind profiles,fluctuating wind speed spectrum,spatial coherence function of fluctuating wind and random wave spectrum,are analyzed and compared.And reasonable functions are selected to describe the characteristics of ocean wind and wave,so as to make the subsequent wind and wave time histories in line with the actual sea conditions.Then,according to the frequency domain characteristics of wind and wave time histories,the frequency domain division interval is determined to ensure the synchronization of simulated wind and wave time histories in time domain.According to the spatial coherence function or coefficients of wind-wave,the wind-wave correlation spectral density is established.On this basis,the wind-wave joint spectral matrix is constructed.The wind-wave joint spectral matrix is decomposed by Chokesky decomposition,and the joint time histories of wind-wave elements with different correlations are generated by harmonic synthesis method.Finally,the combined wind-wave forces are calculated by using the combined time history of wind-wave elements,and the dynamic response of the cable-stayed bridge across the sea under the combined action of wind-wave elements is analyzed.The results show that the wind-wave correlation has a significant impact on the dynamic response of the bridge structure.The stronger the correlation is,the greater the structural dynamic response will be.The correlation of wind-wave is positively correlated with the structural dynamic response.The research results of this paper provide a reference for the structural design of cable-stayed bridges across the sea considering wind-wave correlation,and provide an important basis for further exploring the calculation method of structural dynamic response of bridges across the sea considering wind-wave correlation effect.