Study On Torsion Resistance Of Prestressed Concrete Cable-stayed Bridge With Central Cable Plane

The central cable plane prestressed concrete cable-stayed bridge is increasingly favored by contemporary bridge designers for its beautiful shape,good load-bearing performance,wide driving vision and other advantages.With the continuous development and progress of society,the amount of traffic continues to increase,and the possibility of partial load is getting higher and higher.As we all know,the wider the cross-section of the bridge,the greater the torque the structure will withstand under eccentric loading.However,the diagonal cables arranged in the form of the central cable surface can hardly provide effective torsional stiffness.If the torsion capacity of the main beam is insufficient,it will pose a great threat to the safety of construction and operation,so it is necessary to conduct in-depth research on such bridges.This paper relies on a typical prestressed concrete cable-stayed bridge with central cable plane.The main contents of the research are as follows:(1)Combined with the force diagram of the prestressed concrete cable-stayed bridge on the central cable plane,according to the actual eccentric load,the Midas / FEA analysis software was used to establish the finite element model.The vertical displacement,torsion angle,and support generated from the load The four key indicators of reaction force and stress were analyzed for the torsional performance of the largest single and double cantilever construction stage and the bridge completion stage.The contribution of cable-stayed cables to the overall torsion of the structure under eccentric load is quantified,which indirectly confirms that the torsional stiffness of the central cable-stayed cablestayed bridge is mainly provided by the main beam.(1)Parameterized analysis of box type,lateral width of consolidated pier,beam height,and lateral spacing of cables were carried out,and the degree of its influence on the torsion performance of the full bridge was studied.By continuously changing the torsional moment of inertia of the main beam,a series of sample points about the maximum torsion angle are obtained,and then the maximum torsion angle of the central cable plane PC cable-stayed bridge with a main span of 300 m to 400 m and the main beam are fitted.Function expression of torsion moment of inertia.(3)Based on the theory of fuzzy analytic hierarchy process,a multi-level fuzzy hierarchical state evaluation model for the torsional performance of the central cable plane PC cable-stayed bridge is established,combined with the interval judgment matrix to obtain the optimal weight ratio through the programming solution method.The torsion performance of the bridge was evaluated.