Finite Element Analysis On Shear-lag Effect In Curved Continuous Box-girder With Corrugated Steel Webs

With the increase of bridge span, it is of crucial importance to decrease the deadweight of the superstructure. It is used corrugated steel webs to replace the traditional concrete web. It is a new type of steel-concrete structures by using externally prestressed techniques, which makes full use of the strong shear capability of box-girder with corrugated steel webs and high compressive strength of concrete. it has reasonable mechanic property. Compared with the normal reinforced concrete beam, it has remarkable economical benefit and conforms to the development of lightening of bridge structures. In recent years, Following the rapid development of constructing of interchange and viaduct in city, the curved continuous box-girder which was created by the cooperation of box-girder with corrugated steel webs and single column pier has the characteristics of beauty shapes, light weight, less land occupation and orientation to good view, It is worthily popularized in the engineering application.When the box-girder bends, Normal Stress of box-girder's superior and inferior margin present nonlinear distribution. So it is shear-lag effect of box-girder. There has been many accidents becausing of ignorance of shear-lag effect. Bridge staffs in our country have realized that shear-lag effect is one of the reasons which lead to creaking of concrete box-girder. Especially in modern bridge engineering, Along with widely used in big outriggers of box-girder and large interval between both ribs of single box-beam, we should pay more attention to shear-lag effect of box-girder.On the basis of referring to related documents and analysis of builded bridge, By means of general finite element analysis software ANSYS to study on 3x20m-span curved continuous box-girder with corrugated steel webs, and modeled curved continuous box-girder with corrugated steel webs bridges at different factors which can influence shear-lag effect. Analyzed the documents by comparing with changing Radius of Curvature, width-span ratio, width-height ratio,distance of webs, stiffness ratio of box-girder, twist-stiffness ratio, The numbers of bridge Cross Slab, type of Cross-section by box-girder, the height of web-wave ,and then got the changing tendency of shear-lag effect, the rule of distribution and its characters. The conclusions could be used to engineers to design.