Analysis On Structural Characteristics Of Extradosed Cable-Stayed Bridge And The Pylon's Partially Force

The extradosed cable-stayed bridge has double structural characteristics of cable-stayed bridge and continuous girder bridge.Since its birth,it has shown great potential worldwide.This paper systematically introduces the theoretical and practical experience of the extradosed cable-stayed bridge at home and abroad,and takes the Lhasa Liu Dong bridge,a prestressed concrete extradosed cable-stayed bridge as an engineering example,to analyze the mechanical properties of the bridge and to analyze the local analysis of the bridge tower.(1)Based on the design of the construction drawing,the finite element model of the full bridge of the Liu Dong bridge is established by the finite element software Midas civil.The simulation method of the components in the finite element analysis of the extradosed cable-stayed bridge is described in detail,and the whole process of the construction phase of the Liu Dong bridge is simulated,and the structural displacement of the bridge during the construction phase is analyzed.The influence of concrete shrinkage and creep on the structure after completion is analyzed.Then the calculation and analysis of the operation stage of the bridge are carried out,and the effects of the live load in the operation stage,the temperature change of the system,the temperature gradient of the main beam,the individual action of the wind load and the effect of various combined working conditions are taken into account.(2)The multiple Ritz vector method was used to analyze the natural vibration characteristics of the Liudong Bridge,such as frequency and mode shape.Using the E1 seismic action,the response spectrum of the Liudong Bridge under the action of three-way seismic acceleration alone and three-way combination was analyzed.(3)The finite element software ANSYS is used to analyze the temperature stress of the bridge tower,and the influence of different reinforcement ratio on the temperature field and stress field of the bridge tower is considered under the effect of cold wave.(4)In view of the complex problems of the construction of the ring bridge tower,the finite element model of the bridge tower construction support is set up.The influence factors of the construction load are taken into consideration,and the bearing capacity and stability of the support are analyzed according to the relevant specifications and construction experience.