Mechanics Analysis On Composite Pavement Structure Of Steel Box Girder Bridge Deck

It is always be a hotspot and difficulty to long-span steel box girder that research on pavement materials and structural optimization and others issues.There is great difference between the intensity and other property of commonly used asphalt pavement material and steel bridge deck.Under the influence of driving load,climate and bridge structure deformation,the stress of bridge deck pavement system of steel box girder and deformation are more complex.And it is common to see some distress phenomenon under the operation,such as pavement fatigue cracking,rutting and delamination.The study on mechanical properties of composite bridge deck pavement system of steel box girder has be given to important theoretical significance and practical value.This paper is based on Wuhuan Science and Technology to tackle: research project of slip resistance cracking technology for long-span steel box girder bridge deck pavement system,which takes the flexible bridge deck pavement and rigid-flexible composite pavement scheme on steel box girder which comes up by research group of Wuhan University of Technology as a mechanical analysis object,and refers to the structure of standard section of some steel box girder,to build local three-dimensional numerical model,including the steel bridge deck,u-shaped stiffener,pavement and diaphragm,and to study the mechanical properties of pavement system of steel box girder.The primary research and related conclusion are as follows:Firstly,summarizing the researches of mechanics analysis on the steel bridge deck pavement system at home and abroad,and the using status of pavement material and pavement structure.Then generalizes the common type of damage pavement,puts forward the main relevant mechanical control indicators: the maximum tensile of above and below the layer stress in pavement layer,the maximum shear stress of steel bridge deck and pavement layer interface,the maximum deflection of the pavement surface.Secondly,analyzing two new programs features of composite bridge deck pavement of the steel box girder: one is flexible pavement structure program,consisted of SMA13 upper layer and SMA10 under layer that prepared by high viscosity asphalt,the other is the composite pavement structure program,consisted of SMA13 upper layer that prepared by the high viscosity asphalt and the upper and under layer of light with high tenacity concrete.This pavement structure improves the coordinated deformation properties of steel plate pavement by welding steel bridge panel with shear connectors soldering that tied with steel mesh.Again,referring to the standard structure of Guoyuan no.2,and with the aid of the ANSYS,this paper establishes the flexible pavement of three-dimensional finite element model,including the orthotropic steel bridge panel,transverse diaphragm and double-layer SMA pavement,also,establishes rigid-flexible composite of three dimensional finite element model,including the orthotropic steel bridge panel,transverse diaphragm,lightweight concrete pavement layer,SMA13 upper layer.This paper respectively study the rule of stress variation of two types of composite pavement structure of steel box girder bridge through all kinds of data that obtained by mechanics calculate under car load,then confirm its most unfavorable loading charge in various mechanical control indicators.Finally,making analysis based on the influenced parameters of two kinds of finite element model for steel bridge deck pavement structure: the flexible pavement structure have studied pavement layer thickness,the thickness of the steel bridge deck,u-shaped stiffener thickness,and the influence of the load size to the stress of the steel bridge deck pavement structure of the mechanics index performance;the rigid-flexible composite pavement structure has analyzed the influence of the formation,height and diameter of the shear connectors to the steel bridge deck pavement structure of various mechanical indexes of mechanical performance.At the same time,combined with the results of the analysis,this paper puts forward reasonable suggestions to the mainly parameter selection of pavement structure.