Integrated Design And Optimization Research Of Steel Box Girder Deck And Pavement Structure

In the past hundred years,engineers began to study the feasibility of larger span and larger scale river-crossing projects inspired by the great achievements in bridge engineering construction.The application of large span steel box girder bridge based on orthotropic deck is more and more common,and steel box girder bridge deck pavement technology is the key of long-span bridge construction.Road and bridge experts from various countries have carried out a lot of research on the durability,safety and comfort of pavement layer,and achieved some results.However,due to the increasingly heavy traffic in our country,Even the bridge designers used asphalt pavement materials with excellent performance and high price,the pavement damage problems will often occur in different degrees within the design service life.This shows that the improvement based on the bridge deck pavement mechanical performance can not only be considered from the optimization of pavement material performance:Moreover,the safety of main span structure is generally considered in the design of steel box girder structure,and try to improve the durability,strength and stability of box girder structure.For the accessory structure bridge deck pavement usually only refer to the requirements of pavement design and construction,and integrated designs and optimization according to the stress requirements of pavement layer are very scarce.This paper is based on the existing research results on the influence of Structural characteristics of orthotropic steel deck and pavement materials on pavement layer stress.In order to further improve the service performance,durability and service life of steel deck pavement in our country,the integrated design of orthotropic deck structure and pavement is carried out.The main contents of the study are as follows:(1)this paper established a enterprise three-dimensional finite element model of orthotropic deck pavement system based on the shell-entity elements,and verifies its accuracy with relevant calculation results of other literature.First of all,Determining the level of box girder structural parameters,and find out the most dangerous loading positon which led to the destruction of the pavement.Under the most dangerous loading positon,the influence of box girder structural parameter,vehicle load form and temperature change on the stress of pavement is analyzed.(2)Taking a bridge with existing pavement diseases as an example,the mechanical behavior and fatigue property of pavement layer are analyzed.Finding out the causes of the deck pavement diseases,the methods to improve the fatigue performance of pavement are discussed.(3)The mechanical behavior and fatigue property of different combination scheme of pavement structure at the most dangerous loading positon are studied,and analyze whether the fatigue properties of each structural scheme meets the design and use requirements.Then the mechanical properties and fatigue resistance of different combination scheme of pavement structure are compared and analyzed.(4)The orthotropic bridge deck structural grouping under the condition of different thickness of steel bridge deck is given,which can make the Pavement Stress and deformation optimization.Considering the two experimental factors of orthotropic plate structure scheme and combination scheme of pavement structure,the influence degree of test factors on the fatigue performance of pavement and the optimal combination of different factors and different levels in the research scope are obtained.A new asphalt pavement material-"post mixing" epoxy asphalt concrete is proposed which has the advantages of lower price,shorter curing period and easier control of construction technology compared with the traditional epoxy asphalt concrete.(5)The initial construction cost analysis and the whole life cycle cost analysis of the integrated design of orthotropic steel deck and pavement structure are carried out.Through calculation and analysis,the combination scheme of pavement structure with low life cycle cost,long service life and good mechanical performance is gived.