Effect Of Shear Lag For Continuous Curved Steel-Concrete Composite Box-section Girder

Because of its simple section,good mechanical performance and convenient construction,steel-concrete composite box girder bridge is widely used.The shear lag effect is an important problem in the continuous curved steel-concrete composite box girder.The existing literature mostly studies the shear lag effect of reinforced concrete linear box girder,while the research on the shear lag effect of curved steel-concrete composite box girder is relatively few,and the research on the shear lag effect of continuous curved steel-concrete composite box girder is even less.Therefore,the continuous curved steel-concrete composite box girder of Xiashan Baipeng to Mazhang Tianliao village reconstruction project(Zhanjiang avenue)on line S374 of Guangdong provincial road is taken as a reference,the finite element model is established and the shear lag effect is analyzed.The main research work is as follows:(1)With continuous curved steel-concrete box girder with double box and single chamber as the research object,based on the energy variational method,in defining the appropriate shear lag warping displacement shape function,on the basis of considering the flexural deformation,twisting strain,continuous curve of steel and concrete composite box girder is derived and the solving of differential equation of the shear lag effect.(2)Finite element models of three-span continuous curved steel-concrete composite box girder under static load and dynamic load were established by using finite element software ANSYS.In the finite element analysis,the static load was simplified as uniformly distributed load and concentrated load were respectively loaded at the intersection of web and roof,and the traffic load was simplified as four point loads moving along the intersection line of web and roof,and the reliability of the finite element model was verified.(3)The influence of different structural parameters on shear lag effect of continuous curved steel-concrete composite box girder under static load.The model of continuous curved steel-concrete composite box beam under static load is established by using finite element software ANSYS.The influence of curvature,width to span ratio,roof thickness,web thickness,flange width and number of diaphragms on shear lag effect of continuous curved steel-concrete composite box girder was analyzed.The variation law of shear lag effect under the influence of different structure parameters is obtained.(4)The influence of different parameters on shear lag effect of continuous curved steel-concrete composite box girder under moving load.The ANSYS finite element model under the action of moving load is established.The influence of curvature,roof thickness,web thickness,driving speed,load position,axle weight and number of diaphragm on shear lag effect of continuous curved steel-concrete composite box girder is analyzed,and the variation law of shear lag effect under different structure parameters is found out,and some suggestions on how to reduce shear lag effect in engineering design and construction are put forward.