Papers by Keyword: I-Girder

Abstract: A new type of preflex I-girder with corrugated steel web has been proposed to provide better solution for urban elevated bridge. The purpose of this study is to explore shear stress distribution and deflection of such preflex I-girder. Shear stress distribution in section of steel-concrete composite girder was analyzed by shearing stress integral equation and piecewise function, and a quarter-scale preflex I-girder with corrugated steel web was fabricated and tested. Experimental and analytical results show that the shear stiffness is only depends on corrugated steel web, and the shear stress is uniformly distributed along the height of corrugated web. It is found that the proposed shear stress equation is consistent with the experimental result and the deflection integral equation is agreed well with the FEA result. The result suggests that the shear deflection is as larger as 25.8% of the total deflection, and should take shearing deflection into consideration.

Abstract: The axial stiffness of the corrugated steel plate is negligible by nature of unique geometric characteristics of the plate called as the accordion effect. This unique effect results in high efficiency on post-tensioning. Thus, corrugated steel plate is very suitable for a web of PC-box girder. Recent researches show that strain and stress in sub-panel of corrugated steel webs, that are induced by local bending of the sub-panel, exist even if the axial stiffness is negligible. These strain and stress in sub-panel are important since it might cause fatigue failure of the structure under repeated loading. This study presents the analytical simulation of the accordion effect of the I-girder with corrugated steel webs under pure axial load or bending including the effect of local bending of sub-panel of the corrugated steel webs. Theoretical study and numerical results were combined to develop the simplified equation to evaluate the accordion effect including the effect of local bending of the sub-panel.

Abstract: For I-girder with high strength steel, it is known that the flexural ductility is considerably decreased by increasing the yield strength of material. Thus, it is necessary to conduct a study for guaranteeing proper flexural ductility of I-girder with high-strength steel. In this study, the evaluation of flexural ductility of negative moment region of I-girder with high strength steel where yield stress of steel is 690Mpa is presented based on the results of finite element analysis and experiment. From the results, it is found that the flexural ductility of the I-girder is significantly reduced due to the increase of elastic deformation and the decrease of plastic deformation ability of the material when the yield strength increases. This study proposed equation predicted flexural ductility of high strength steel in negative moment region. It is also proposed the method to improve the flexural ductility by an unequal installation of cross beam and an optimal position of cross beam. Finally, the effects of the unequal installation of cross beam on the flexural ductility are discussed based on the finite element results and the experimental results.