Study On Mechanical Performance Analysis Of Steel Approach Bridge Without Diagonal Web Members

With the vigorous development of the port,the wharf construction gets continuous improvement.The steel approach bridge,which is a new form of the piers,is favored by these bridge stylists,because of its good economic performance and reliable mechanical performance.The bridges,which are at the harbor and inland-river,are under wind load,and the stability problem of them can't be ignored.As a basic bridge of the steel arch bridge,the steel approach bridges without diagonal web members play an important role in the wharf construction,and the strength,the stiffness and the stability are the mian contents of the analysis.As a result,the stability problem of the bridge is more important than ever.This paper is disserted on the engineering background on a steel approach bridge without diagonal web members,which's span is 60 meters and which is located in an petrochemical general factory crude oil wharf in Jinmen city of Hubei province.The space of whole bridge modle is established by using the Midas/Civil2015,which is the general finite element software.First of all,strength,stiffness and stability of the steel approach span,which is completed,is comprehensively studied.The influence of different speed of wind which's speed increases from zero meters per second to 60 meters per second,on the steel access bridge's capacity of ultimate bearing.On the basis of this,the ultimate bearing capacity of the steel bridge under different wind speed condision is studied.Secondly,doing analysis in order to find the different advantage of the two different structure forms steel approach bridges in mechanical performance and economic performance out,and the analysis based on the vertical maximum deflection and load conditions consistent are equal.Furthermore,the influence of the arch ribs on the stability of the steel bridge is analyzed.Finally,the influence of the factors such as the thickness of steel,the section of arch rib,the ribs of ribs and the inclination of arch ribs on the stability of steel bridge are analyzed by using independent variable method.According to the above research,the main conclusions of this paper are as following:(1)Basing on the static analysis of the whole steel approach bridge,both the stress,the stiffness and the stability of its are satisfied with the requirements of the safety of the steel structure design specification.Observing the bucking modle development of the structure,find out that four kinds of failure modes occur mianly in the steel bridge,the local buckling instability of arch rib firstly happened on the steel approach bridge.Compared to the solid-web,the steel approach bridge without diagonal web members spends little steel.And there is not difference between them.(2)With the increasing of wind speed,the stability coefficient of the steel bridge has a decreasing trend,and the ultimate bearing.And the ultimate bearing capacity of the steel approach bridge is very decrease significantly.In particular,when the wind speed is greater than 20m/s,the stability and the ultimate bearing capacity of the steel approach bridge have a sharp decline.(3)The effect on the stability of the different flat contact form on the steel approach bridge is studied,studies have shown that different arrangement flat contact with the stability of the steel approach bridge is different.And the stability coefficient is the largest when the flat contact is put out by using continuous arrangement.(4)When compared the stability of the bridge between the arch rib use among the welded steel H-section,hot-rolled H-beam,steel box girder,the study found that when the arch rib use steel box section,the stability coefficient and the ultimate bearing capacity of the bridge are the largest,the second is hot-rolled h-beam,and the welding H-beam is least.(5)The effect on the stability of the different of ribbed arch rib in the steel approach bridge is studied,studies have shown that ribbed arch rib of the steel approach bridge was helpful to improve the stability.And the effect on arch foot use ribbed arch rib is obvious.The improvement of the stability when arch rid plus two longitudinal ratios is better obvious than when plus a longitudinal.