Study On Ultimate Bearing Capacity Of Curved Composite Box Girder With Corrugated Steel Webs

With the development of rail transit in our country,in order to meet the needs of the topography and urban road planning,the application of curved bridges is increasingly widespread.As a new type of bridge structure,corrugated steel web box girder bridge has been gradually applied to curved bridge engineering.Compared with linear bridges,curved corrugated steel web box girder bridges have more obvious bending-torsion coupling effect and more complex mechanical properties.Moreover,the bending-torsion correlation has not been taken into account in the current bridge specification,and the ultimate bearing capacity of curved corrugated steel web box girder bridges has been overestimated,which has potential safety hazards.The ultimate bearing capacity of curved corrugated steel web box girder which considered the correlation between bending and torsion was studied in the current study.Besides,the stress characteristics of its limit state were analyzed and the formula for calculating the bearing capacity of curved corrugated steel web box girder was also given,which could provide some reference for the formulation of relevent specification.The main contents include:(1)Based on the oblique bending failure model,the bending-torsion correlation formula of the curved corrugated steel web box girders under the composite action of bending and torsion was derived,and the bending-torsion correlation curve was drawn.(2)The finite element model of curved corrugated steel web box girder bridge with the span was designed and established.The failure mechanism of curved corrugated steel web box girder under the composite action of bending and torsion was explored by studying the stress and crack development of reinforced concrete and corrugated steel webs.(3)The influence of bending-torsion ratio,concrete strength,thickness of corrugated steel webs,reinforcement ratio,height-width ratio and other parameters on the ultimate bearing capacity of curved corrugated steel web box girder was studied according to the finite element model(4)Based on the existing bearing capacity formula and finite element parameter analysis data,the bending-torsion correlation curve of curved corrugated steel web box girder was obtained by data fitting and then combined with the Shear-Torsion correlation curve of corrugated steel web box girder,the ultimate bearing capacity formula of curved corrugated steel web box girder was proposed.The bending-torsion correlation curves of curved corrugated steel web box girders were drawn,and the formula for calculating the ultimate bearing capacity of curved corrugated steel web box girders were also derived in the current study,which could provide reference for engineering design and the setting of relevent specification.