Research On Mechanical Performance Of Corrugated Steel Web PC Box Girder Bridge Segments

In recent years,corrugated steel web structures have been widely used in the field of bridge engineering.Scholars at home and abroad have carried out in-depth research on the bending,shear,torsion and stability of box-girder bridges with corrugated steel webs,but most of them are based on the analysis of simple structures(equal-section,simple-supported beams).Relying on engineering examples,this paper closely focuses on the three characteristics of cantilever construction,variable cross-section,and new type of shear connectors for PC box girder bridges with long-span corrugated steel web.The web is stable.The main research contents and results include:(1)According to the engineering example,combined with the Midas finite element software to simulate the cantilever construction process of the bridge,the cross-section internal force values of the key sections under different construction conditions were obtained.(2)Based on the differential element method and the reciprocal theorem of shear stress,the calculation formula of the shear stress of the box girder with variable cross-section corrugated steel webs is deduced.Based on this,a simplified calculation formula is proposed.The energy method was used to derive the formula for calculating the normal stress of the concrete roof and floor.Through comparative analysis of finite element simulation results,theoretical calculations,and construction monitoring values,research shows that the simplified section stress formula and finite element simulation results presented in this paper are reasonable and reliable.(3)Based on the analysis results of five sets of finite element test specimen models,the composition of the S-PBL + stud shear connector force transmission mechanism and the shear capacity are revealed,and the calculation of the shear capacity in this paper is based on the principle of linear superposition.formula.Compared with the existing theory,the results show that the calculation formula and finite element simulation results proposed in this paper are reasonable and reliable.(4)Based on the control variable method,10 groups of test specimen models were designed to study the effects of concrete strength,the number of holes in the steel plate,the diameter of the studs,and the diameter of the reinforcing bar on the shear capacity of the shear connection.The analysis shows that increasing the concrete strength is the most significant for improving the shear capacity of the shear connection.(5)Abaqus finite element software was used to perform linear analysis on 12 groups of steel web specimens.The results showed that the buckling strength of the corrugated steel web increased with the increase of the wave angle and the thickness of the steel web,and the numerical fitting was performed.The calculation formulas of buckling strength and shear strength are obtained.(6)The analysis of five groups of nonlinear finite element models by introducing initial defects of steel webs shows that the wave size defects significantly reduce the ultimate buckling strength of steel webs and the structure is sensitive to nonlinear factors.