Study On The Mechanical Properties Of The Steel Beam Supporting The Steel Arch-Gate

The steel arch-gate's supporting steel beam structure combines the advantages of The steel beam with good seismic performance,accurate and fast assembly and deep beam support form which can effectively improve the stress state of pier and supporting body.This supporting form can give full play to the advantages of steel with high strength and good tensile properties,and can effectively improve the eccentric state of the pier.Generally,the supporting steel beam is in close contact with the gate pier through the prestressed anchor cable.At present,steel beam structure is widely used in hydraulic engineering,construction engineering,and bridge engineering,its security is significant.In this paper,the steel beam used as the support structure of the steel arch-gate is studied,and the influencing factors of the mechanical properties of the supporting steel beam are deeply analyzed,and it provides reference for the design of the steel arch-gate's supporting steel beam.In this paper,the three-dimensional finite element method is used to study the influence of the main components size and structural arrangement of the steel arch-gate's supporting steel beam's mechanical properties,and the relationship between the pull-anchor coefficient and the stress and displacement of the prestressed pier and the supporting steel beam on the premise of satisfying the stability of steel beam.The main research contents and results are as follows:(1)By changing the flange width-to-thickness ratio and the web thickness ratio in the finite element model of the steel arch-gate's supporting steel beam,the influence of the main component size of the steel arch-gate's supporting steel beam on its mechanical properties shows that:each component stress of the steel arch-gate's supporting steel beam is roughly symmetrical to the location of the steel beam midspan,and the tensile stress of the steel arch-gate's pivot bearing plate and the location of the prestressed anchor cable is the largest.The downstream flange stress of steel arch-gate's supporting steel beam is greater than the upstream flange stress and the webs.Changing the flange width-to-thickness ratio has little effect on the stress of steel arch-gate's supporting steel beam's each component,changing the web thickness ratio has great effect on the stress of the flange and web,and has little effect on the stress of the stiffener.Whether the flange width-to-thickness ratio or web thickness ratio is increased,the maximum deflection of steel arch-gate's supporting steel beam is increased.The results of analysis and calculation results show that the flange width-to-thickness ratio is 32,and the web thickness ratio is 59.At this time,the steel arch-gate's supporting steel beam can not only meet the requirements of the code for strength and stiffness,but also give full play to the material properties of the steel beam.(2)By establishing the finite element model of supporting steel beam with the different transverse stiffener distance and webs inclination,the influence of the structural arrangement of the steel arch-gate's supporting steel beam on its mechanical properties shows that:reducing the transverse stiffener distance can improve the flange and transverse stiffener stress,and can effectively reduce the deflection of steel arch-gate's supporting steel beam.It is suggested that the transverse stiffener distance of the steel arch-gate's supporting steel beam should be1/3h0,at this time the steel beam material performance is given full play,both economical and reasonable.Changing the webs inclination of the steel arch-gate's supporting steel beam has great influence on the stress of the downstream flange and the maximum deflection of supporting steel beam.When the webs inclination of the supporting steel beam is 2°,the deformation and stress of the steel arch-gate's supporting steel beam are small,which is economical and safe.(3)By changing the pull-anchor coefficient of the finite element model,the influence of pull-anchor coefficient on the mechanical properties of prestressed pier and supporting steel beam shows that:the arch steel gate adopts steel beam supporting structure to effectively avoid the tension stress of anchor block type pier's neck,but there is a large tension stress in the contact surface between pier and supporting steel beam,which needs to be strengthened.The stress of prestressed pier,the displacement of pier along the river and in the vertical direction,the stress of supporting steel beam's each component and the maximum deflection of steel beam are greatly affected by changing the pull-anchor coefficient;Based on the comprehensive analysis of the variation law of stress and displacement of prestressed pier and supporting steel beam's with the anchor coefficient,it is suggested that the value of anchor coefficient should not be more than 2.1.At this time,the stress and displacement of prestressed pier are small,the stress value of supporting steel beam's each component can satisfy the code requirement,and the deformation of the steel beam is smaller.