Analysis Of Shear Lag Effect Of PC Composite Box Girder Bridge With Corrugated Steel Webs

The compressive performance of concrete has been fully exerted by the external prestressed corrugated steel web box girder,which has the advantages of light weight,good shear resistance,clear stress on the top and bottom plate and web parts,etc.,and has been widely used in highway bridges in China in recent years.At present,there are still few studies on corrugated steel web box girder,especially its shear hysteresis effect,based on this,in order to further improve the research on the mechanical properties of corrugated steel web box girder,this paper takes the Bajiang River Bridge as the engineering background,based on the shear hysteresis theory of ordinary box girder,combined with the characteristics of corrugated steel web box girder bridge,and analyzes and calculates the shear hysteresis effect of long-span corrugated steel web box girder bridge under different construction stages and load conditions by establishing a finite element model,and discusses its change law.The influence of geometric parameters on the shear hysteresis effect was analyzed,and the following work was completed:(1)Establish the plane rod system model and the spatial entity finite element model of the long-span corrugated steel web composite box girder bridge,simulate each construction stage,and discuss the waveform of the different construction stages with multiple key sections as the research background.Distribution law of shear lag effect of steel web composite box girder bridge;(2)The formula for calculating the shear lag effect of the long-span corrugated steel web composite box girder bridge using the analogy method is derived.Shear lag effects are studied;(3)Based on ANSYS finite element analysis software,the distribution law of shear lag effect of long-span corrugated steel web box girder bridges with different width-span ratio,height-span ratio and roof thick Ness was studied,and the influence of corrugated steel web was investigated.The geometric parameters of the plate shear lag effect are summarized;The results show that the shear lag effect of the long-span corrugated steel web composite box girder bridge is in a dynamic change with the continuous construction stage.It is relatively slow,and the end section in the maximum cantilever state has the largest shear lag effect;the three-bar comparison method can effectively and reliably calculate the shear lag effect of large-span corrugated steel web girder bridges;From the numerical results,it was shown that the main influencing factorfor shear lag effects are the width-span ratio and the thick Ness of top plate in a single-box girder,which should be taken into account for thedesign.This results in this thesis about the shear lag effects of long-span corrugated steel web composite box girder bridges may provide a reference for the design and construction of subsequent similar projects.