The Analysis Of Vertical Earthquake Impact On The Large-span Corridor

Because of various forms,beautiful appearance,good performance of usage,large-span structure is widely used in daily life.However,the large-span structure acts very sensitive to the earthquake.With the increase of the span,the earthquake performance of the large-span structure will be affected,and it is more obvious when facing the vertical earthquake.Therefore,it is of great significance to analyze the long-span structure under the situation of vertical earthquake.The beginning of this essay,it analyses the model by using the modal analysis,through the span changes analyses the influence on the vibration structure and the vibration period.Secondly,using the response spectrum method to demonstrate the importance of the vertical earthquake's effect.Then,analyses the vertical earthquake action under different earthquake intensities,in order to verify the effect of the structure that seismic intensity causes.Finally,the deformation and stress of the structure are analyzed by the coefficient method,the response spectrum method and the time history analysis method respectively,and the seismic design of the lower support columns is carried out.The main work of this paper is as follows:(1)In the modal analysis of the large-span steel truss,it is found that the vertical vibration of the structure occurs in the fourth order mode,and the change of the span show that with the increase of the span,the order of the vertical vibration is advanced,and the vibration period of the structure also increases,which indicates that the change of steel truss span has great influence on the dynamic characteristics of the structure.(2)Using the response spectrum method,the displacement of the joints and the internal force of the rods under the different earthquakes are analyzed,and it is found that the vertical earthquake action has a great influence on the structure.then the response spectrum analysis of the steel truss with different spans show that with the increase of the span,the earthquake response of the structure also increased.(3)The vertical displacement or the vertical acceleration of the joints,and internal force coefficient of the rods are analyzed by the response spectrum method and the time history analysis method,and compared with the coefficient method specified in the standardized,it is found that the results of the time history analysis are more suitable to the earthquake response of the structure.Then,through the time history analysis of the different earthquake intensities,it is found that the earthquake response is obviously enhanced with the increase of earthquake intensity under the action of the vertical earthquake.(4)Considering that the vertical earthquake may also have an impact on the steel truss under the support column,the vertical earthquake action should be taken into account in the seismic design of the lower support column by the internal force combination calculation.