Numerical Simulation Study On Static Wind Load For Typical Steel Box Girders

Bridge Wind Engineering(BWE)is an interdisciplinary,which is developing very fast with the development of modern bridge.The effects of wind on the bridge structure are very complicated and mainly influenced by three factors: wind characteristics,the force performance of the bridge structure,and interaction of wind and bridge structure.The effects of wind on the bridge structure contain both static effect and dynamic effect,study on the static characteristics of BWE not only has its own reality,but also can be the basis of dynamic performance of bridges.Currently the study on BWE mainly depends on wind tunnel test,and numerical simulation method is just a supplement.With the rapid development of computational fluid dynamics(CFD)and computer science,CFD method will be developed and applied in engineerings more and more.In this paper,the author used numerical simulation method to solve BWE problems.Firstly,the author calculated “flow around one circular cylinder problem” and “flow around three circular cylinders problem”,then the author calculated “flow around rectangular section problem”,these results can prove the numerical simulation's reliability and can provide references to the BWR problems.In the past,many researchers used standard ?-? turbulence model to simulated flow around near-streamlined box girder because of the limitation of computer performance.With rapid development of computer science,SST ?-? turbulence model is subjected to the value more and more.In this paper,the author firstly calculated four typical engineering cases by using both standard ?-? turbulence model and SST ?-? turbulence model.Through this part of work,following conclusions are obtained:(1)both standard ?-? turbulence model and SST ?-? turbulence model has enough precision,but the accuracy of SST ?-? turbulence model is better;(2)SST ?-? turbulence model can get much more details of the flow field.As an engineering application,the author calculated the static coefficients under different wind attack angles and Reynolds number of Chongqing Egongyan Track Typical Bridge's box girder,and systematically analyzed the change law of the static coefficients with wind attack angle and Reynolds nuber.Because Chongqing Egongyan Track Typical Bridge is close to the already existing Chongqing Egongyan Bridge,the aerodynamic interference of the two bridges must be taken into account.So the author then calculated static coefficients of the two bridges under different spacing ratio,wind attack angles and Reynolds number,then the author systematically analyzed the change law of the static coefficients and aerodynamic interference of the two bridge girder boxes with wind attack angle,Reynolds nuber and spacing ratio.The calculation results of this part can be used as reference data to the design and wind tunnel tests.