Analysis And Research On Shear-lag Effect In Combined Box-girder With Corrugated Steel Webs

Composite box girder with corrugated steel webs is a new kind bridge structure, which uses fold effect of corrugated steel webs to replace the traditional concrete girder, and also uses a lot of new type of externally prestressed。Compared with the traditional concrete box girder bridge, it has many advantages, such as small weight, good crack resistance, aesthetically pleasing, etc., thus it has been widely promoted and used in the countries all over the world. On the basis of widely collecting and understanding about the research results on shear lag effect of corrugated steel webs, this paper is mainly for a simply model supported beam with a single box and a single chamber, it total length is 3 meters,it calculation of span is 2.8, meters. the main work is as follows:(l)It introduces the development of corrugated steel web composite box girder bridge and structure characteristic, and the advantages and disadvantages of this new type of bridge structure. Then introduces the research status of domestic and foreign scholars from various countries on a combination of box girder with corrugated steel webs. Finally, it explains the basic concepts of shear lag effect, and various methods of analyzing shear lag effect;(2)Using the energy variational method and peace section assumes, it deduces Corrugated steel web plate shear lag of box girder bridge differential control equation, computes shear lag coefficient of span section under different load combinations. And then introduces how to use the finite element method to model composite box girder with corrugated steel webs and computers it. Finally, compared the results of finite element analysis with the results of energy variational method, verify the correctness of the theoretical formula is derived;(3)It analyzes various geometric parameters such as high aspect ratio, hanging wing than, wave, web Angle on the influence of shear lag effect detaily. The analyzes the shear lag coefficient along the lateral variation law, and the transverse diaphragm effect on the shear lag coefficient;(4)This paper briefly introduces the effective distribution width of norms in domestic and foreign, Introduced the concept of effective width ratio According to the different width span ratio of effective width ratio Fitting the experience formula with effective width ratio and the wide span ratio Through compareing with the results of other documents and specifications, verify the correctness of the formula.This paper got the further research on the shear lag effect of corrugated steel webs composite box girder by two different methods, deduce the calculation formula of shear lag on corrugated steel webs composite box girder bridge across the cross section calculation, establish the finite element model of corrugated steel webs composite box girder bridge。Analyze the various factors of effecting shear lag, propose fitting formula that applicable to engineering practice and calculation formula of the chart。Through calculating chart and fitting formula, calculate the shear lag coefficient of corrugated steel webs composite box girder bridge easily, in order to guide such construction and design of the bridge。...