Research On Mechanical Properties Of Orthotropic Steel Deck Plate With Semi-opening Longitudinal Rib

As a currently important structural form of large and medium span steel bridge deck,orthotropic steel deck plate is favored by various countries bridge designers because of the characteristics of light weight,high ultimate bearing capacity,wide application range,short construction period,small building height and beautiful appearance.The application of orthotropic steel deck plate has become a symbol for the design and manufacturing level of a national steel bridge.However,the structure and stress of orthotropic steel deck plate are complex,and it directly bears the repeated action of the wheel load of the vehicle,which become one of the key issues affecting the safety and durability of steel bridges.As a new type of orthotropic steel bridge deck structure,the semi-open longitudinal rib orthotropic steel bridge deck combines the characteristics of closed ribs and open ribs,which can improve the stress of the steel bridge deck and improve the durability of the steel bridge deck.In this paper,the semi-open longitudinal rib orthotropic steel bridge deck structure is taken as the research object,and try to get its mechanical properties and design parameters,which provide reference for the design and construction of semi-open longitudinal rib orthotropic steel bridge deck.The main work and the corresponding conclusions are as follows:(1)Based on the engineering background of the Xingxinggang Bridge,the finite element analysis model of the bridge segment of the semi-open longitudinal rib orthotropic steel bridge deck structure was established for stress analysis.The results show that under the action of the rear wheel axle load of the vehicle model with different weights in the structure and the vertical and horizontal directions,the structural force of the semi-open longitudinal rib orthotropic steel bridge deck has obvious local effects,and the maximum equivalent stress of each member.Change has a certain law.(2)Based on the specification and the original design concept of the semi-open longitudinal ribs,combined with the large longitudinal rib design,a semi-open longitudinal rib size is designed.The designed half-opening longitudinal rib height is 300 mm,the bottom plate width is 80 mm,the longitudinal rib web spacing is 360 mm,and the half-opening longitudinal rib has a bending radius of zero(takes a 90° angle form).(3)The plate thickness parameters of the top plate,the semi-open longitudinal ribs and the transverse rib webs are combined and analyzed to reflect the vertical maximum deflection of the overall stiffness of the structure,the roof flexural span ratio reflecting the local stiffness of the structure,and the maximum equivalent stress of each component.As the benefit index of structural analysis,the main tensile stress of the structural details of each component is taken as the cost index.According to different benefit weight ratios,the cost-benefit analysis model of the thickness combination parameters of each component is established,and finally the cost is The ratio of the benefit to the benefit(matching coefficient)is used as the evaluation index of the parameter combination.A method for comparing the thickness parameters of the structural members of the semiopen vertical rib orthotropic steel bridge deck is proposed.Finally,taking the Tengxinggang Bridge as the engineering background,based on the designed semi-open longitudinal rib size,the benefit weight ratio is 0.125,and the thickness of the top plate is 16 mm,the thickness of the semi-open longitudinal rib is 8mm,and the thickness of the transverse rib web is 10 mm.(4)Based on national norms and engineering examples,four types of cross-sections of transverse rib webs were designed and mechanically analyzed.The results show that the stress level of the curved free edge under the four opening patterns is higher than the stress level of the free edge of the straight opening.From the maximum equivalent stress of the member and the stress level of the free edge of the arc,the four types of design are open.In the hole type,the hole type 2 and the hole type 3 are superior,the hole type is the first time,and the hole type 4 is the most unfavorable.