Seismic Mitigation Performance Analysis Of Main Tower Structure Of Long-span Cable-stayed Bridge Under Earthquake Action

With the fast development of economy and the rapid progress of modern architectural technology,bridges play an increasingly significant role in modern infrastructure.Among them,the long-span cable-stayed bridges are highly competitive in modern bridges.In recent years,Cable-stayed bridges are becoming increasingly common worldwide and its span is becoming bigger and bigger.Several super grade km cable bearing bridges have been built in China and many magnificent MTRS sea-crossing bridges are being planned or under feasibility study.Some bridges are being planned or under feasibility study.Some bridges mentioned above are located in the meizoseismal area of China.However,the fundamental frequency of cable-stayed bridges is low and this may produce large displacement under the action of a strong earthquake.The main components,such as main tower,of cable-stayed bridge may be damaged or even destroyed under this condition.Main tower is the main bearing structure and main tower damage will cause huge economic losses and the whole bridge will be paralyzed in consequence.This also have a negative influence on earthquake relief work.In order to avoid serious damage,aseismic design of bridges is necessary.Energy dissipation and design of bridges can be changed to prevent collapse.The main research contents are as follows:(1)In this paper,the main tower structure of large span cable-stayed bridge as the research object,using ANSYS to analyze the structural.Use curvature ductility ratio to analyze the effect of the main tower structure under different intensity earthquakes.(2)Using the knockdown analysis to select the cross-sectional shape and the material of the subsidiary energy-consuming member,so that they can bear the external load as a part of the structure in the normal state,also they can yield before the main tower structure during the earthquake to consume energy.(3)Aiming at the damage situation of the main tower structure,attach the auxiliary energy dissipation components to the main tower structure of the cable-stayed bridge,using numerical method to study the seismic performance before and after the additional wall-beam and energy dissipation capacity,with additional components to yield,energy consumption to achieve stable and effective energy dissipation effect,in order to control the main tower structure damage,and further analysis of the structure of the effect of damage control.(4)This paper analyzes the layout scheme of the attached energy consuming energy component on the main tower,and obtains the optimal layout scheme of the attached member,to obtain the optimal dissipation effect.