Mechanical Performance Analysis Of PC Composite Box Girder With Corrugated Steel Webs By Cantilever Construction Method

As a new type of structure,PC composite box girder with corrugated steel webs can make full use of the material characteristics of concrete and steel.In practical engineering,most of the continuous beams are constructed by cantilevers,and it has a very broad development prospects.In order to study the mechanical characteristics of this kind of bridge by cantilever construction,this paper relies on the National Natural Science Foundation of China: Research on Bending and Torsion Mechanism and Computational Theory of Prestressed Concrete Curved Composite Beams with Corrugated Steel webs(51778377),takes the main bridge of Yuxi River Bridge as the engineering background,uses Midas/FEA finite element analysis software,establishes the solid element model of the bridge,and compares the solid element model with the corresponding flat steel web box girder,and analyses the mechanical characteristics of PC composite box girder with corrugated steel web in construction stage and the effect of shrinkage and creep in completion stage.And the bending and torsional behavior under eccentric load.The main conclusions are as follows:(1)Under comprehensive load,the longitudinal normal stress of corrugated steel webs of this kind of structure is very small,and the axial force on the section is mainly borne by the concrete roof and floor;the shear stress of corrugated steel webs is larger,and the shear force on the section is mainly borne by the webs;(2)Under bending load,the longitudinal strain of corrugated steel webs composite box girder is basically zero in the web height range.The longitudinal strain of concrete roof and floor can approximately form a virtual plane,which basically conforms to the “quasi-flat section assumption”.(3)Under the prestressing load,the vertical normal stress level of the concrete top and bottom slabs of PC composite box girder with corrugated steel webs is relatively high,which can effectively utilize the prestressing force.(4)After long-term shrinkage and creep,the distribution of axial force of PC composite box girder with corrugated steel webs is small,and the concrete roof and floor still bear the main axial force.(5)Under eccentric load,the distortion resistance of corrugated steel web box girder with single box and three rooms is better than that of flat steel web box girder with the same material and thickness,while the torsion resistance of corrugated steel web box girder with the same material and thickness is worse than that of flat steel web box girder with the same material and thickness.