Study Of Construction Simulation Of PC Box Girder Bridge With Corrugated Steel Webs And Mechanical Behavior Of Composite Webs

PC composite box girder bridge with corrugated steel webs,as a new type of steel-concrete composite structure bridge,has the characteristics of light weight,high efficiency,low construction cost and convenient construction.The corrugated steel webs bridge is mainly composed of corrugated steel webs,concrete top and bottom slabs,internal and external prestressing tendons.The corrugated steel webs are used to replace the traditional concrete webs of box girders.Its mechanical properties are quite different from those of traditional concrete box girders in the construction stage.In order to clarify the stress state,it is necessary to analyze the stress state of the superstructure of the box girder bridge with corrugated steel webs in the construction stage.The local structure of the composite webs(lining concrete)is necessary for the analysis of the bending,shear and buckling stability of the cantilever beam in the maximum cantilever construction state.In this paper,the development and research status of PC composite bridges with corrugated steel webs at home and abroad are studied.The deflection calculation of box girder under shear deformation,the axial stiffness of box girder,shear mechanical properties and buckling stability calculation are described in detail.Taking a PC composite continuous beam with corrugated steel webs as the engineering background,this paper uses Midas Civil software to build the bridge structure pole model to simulate the construction process and stress analysis of the upper structure;uses Midas FEA software to build the maximum cantilever entity model of the bridge,and compares and analyses the effects of different length and thickness of lining concrete and 1# and 2# steel webs thickness on the mechanical properties of the maximum cantilever box girder.The results show that the concrete compression,tension and construction deflection of the corrugated steel webs bridge meet the requirements of the code,and the structure does not undergo any form of buckling;in the bending analysis of the maximum cantilever structure,the normal strain of the box girder section conforms to the "quasi-flat section assumption";the change of the length and thickness of the lining concrete has little effect on the maximum cantilever beam deflection,but has a great influence on the deflection near the support.The optimization of the length and thickness of lining concrete can effectively reduce the shear lag effect of section,and with the increase of the length and thickness of lining concrete,the shear lag effect of section near the support decreases correspondingly,while the shear lag effect of box girder near the middle span and the maximum cantilever end does not improve obviously;When the thickness of lining concreteexceeds 20 cm,its bearing shear force exceeds 60%,and the thickness of lining concrete exceeds 80 cm,the change of shear load-bearing ratio is no longer obvious.The thickness of corrugated steel webs of block 1 and 2(16mm,20 mm,25mm,30 mm and 35mm)has little influence on the shear stress of the whole maximum cantilever corrugated steel webs,but has a great influence on the shear stress of block 1 and 2 webs.With the increase of the length and thickness of lining concrete,the ultimate buckling load of maximum cantilever corrugated steel webs increases gradually,and local buckling of corrugated steel webs occurs under the ultimate buckling load.