Study On Static And Dynamic Performance Of Corrugated Steel Webs-UHPC Composite Continuous Box Girder Bridge

This paper develops a novel continuous composite box girder bridge by combining ultra-high performance concrete(UHPC)with corrugated steel webs(CSWs)to overcome the weaknesses of traditional long-span prestressed concrete(PC)continuous girder bridges,such as excessive dead load and deflection at the mid-span,and cracking in the webs.To study the shear lag effect of CSWs-UHPC continuous composite box girder bridge,This paper uses a finite beam segment approach mixed with a general finite element method,This method is based on the energy variational approach,the shear lag coefficient matrix and generalized load array of beam element are obtained by the variational differential equations and the unit boundary conditions.The main research work is as follows:(1)Developing a novel structural style of long-span CSWs-UHPC composite continuous box girder bridge.The static and seismic performances of the CSWs-UHPC continuous composite box girder bridge are investigated,CSWs-UHPC composite continuous box girder bridge is compared to CSWs-normal concrete(NC)and PC continuous composite box girder bridges.The results reveal that:when compared,respectively,with the CSWs-NC composite box girder bridges and PC box girder bridges,the self-weight of the proposed composite structure is reduced by 45%and 54%.The CSWs-UHPC composite continuous box girder bridge is economically competitive throughout its life cycle.The static properties of the developed CSWsUHPC composite structure meet the requirements of the specification.The inertia load is reduced significantly as the dead weight of the superstructure is reduced,making the CSWs-UHPC composite box girder a type of bridge with excellent seismic performance.(2)The reasonable girder depth at the middle support and mid-span are analyzed.The ratio of the reasonable girder depth at the middle support to that at mid span(Hs/L)is 1/16～1/22,and the ratio of the reasonable girder depth at the mid-span to that at the middle support(Hm/Hs)is 1/1.5～(-0.2+0.029L/Hs).(3)To indicate that the finite beam segment method is useful in studying the shear lag effect of continuous box girders,the finite beam segment method calculation results are compared to the finite segment method,test results,theoretical analysis method and the finite element numerical method,and the data are in good agreement.The finite beam segment approach is used to investigate the shear lag effect of a CSWs-UHPC composite continuous box girder bridge.In the maximum cantilever construction stage and operational phase of CSWs-UHPC composite continuous box girder bridge,the longitudinal distribution of shear lag coefficient and the transverse distribution of normal stress in the top flanges of control section under different loads are obtained.(4)The influence of changing the ratio of middle support girder depth to middle span length(Hs/L)and the ratio of middle span girder depth to middle support girder depth(Hm/Hs)on the shear lag effect of CSWs-UHPC composite cantilever box girder and continuous box girder is investigated using the finite beam segment method.