| In recent years,under the premise of following the construction of ecological civilization,the country has gradually accelerated the construction of bridges for transportation,especially the construction of deep-water long-span bridges in the reservoir area.Under the action of strong earthquakes,the hydrodynamic pressure caused by the water in the reservoir area will affect the dynamic characteristics of the structure and the earthquake response,causing adverse effects on the bridge.In view of this,based on the theory of potential fluids and relying on the actual engineering of the Shuang He Bridge,a comparative analysis model of cable-stayed bridges without water and full tanks was established,and the influence mechanism of the water body in the reservoir area on the dynamic characteristics and seismic response of cable-stayed bridges was studied.Combined with this project,we will explore the effects of changes in water depth,internal and external water,changes in the cross section of pier columns,and changes in tilt angle of towers to the seismic response of the tower,and provide a certain degree of application for the coupling of water and towers in practice.Reference guide.The main research contents and conclusions of this article are as follows:1.Introduce the theoretical research method and current situation of the coupling effect of pier water at home and abroad in detail at present,and summarize the calculation methods of the dynamic pressure of China’s highway and railway seismic design code and Japanese bridge seismic design code;2.Based on potential fluid theory,the dynamic responses of cable-stayed bridges subjected to vertical,vertical and horizontal and vertical earthquakes are analyzed for both water and reservoir-free conditions.It is found that the water in the reservoir area can significantly reduce the natural vibration of cable-stayed bridges.The frequency and the magnitude of the natural frequency decrease along the short side of the tower are larger than the direction along the long side of the tower.Under the two conditions of operation,the peak value of the tower top displacement and the peak value of the internal force at the bottom of the tower are lower than the anhydrous state.A certain degree of increase,and the water body has the greatest influence on the bottom shear force;3.Based on the study of cable-bridge coupling effect under seismic action,the coupling effects of the outer waters and the outer waters plus the inner waters with the bridge towers are discovered:Under two conditions,the self-vibration frequency of the bridge tower will decrease with the increase of the water depth of the bridge tower.In the case of the same depth,the effect of water interaction on the seismic response of the bridge tower is greater than that of the external water.Therefore,it is necessary to analyze the interaction of water and water in the inner domain;4.Based on the study of cable-bridge coupling effect under seismic action,the influence of cross-section changes on the coupling effect is discussed.It is found that the change of the cross section can change the influence of water on the dynamic response of the pier column.After optimization of the pier cross-section in the actual water can have good shunt effect,but due to the pier-water contact area increases,thus increase the dynamic water pressure acting on the pier wall and affect the dynamic response of the pier;5.Based on the study of cable-bridge coupling effect under seismic action,it is found that the influence of water bodies on the self-vibration frequency and the seismic response peak of the bridge tower is also different.When the Angle between 60° and 90°,the water’s influence on the displacement of the top and shear and bending moment of the bottom decreases with the increase of Angle,namely the more inclined the bridge tower is,the more influence the water body has on the seismic response of the structure. |
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