Shear Transfer Analysis Of Variable Cross-section Continuous-system Beam Bridge With Corrugated Steel Webs

Prestressed concrete box girder bridge with corrugated steel webs is a new type of composite bridge, the existed researches usually described simply and qualitatively on the shear properties of corrugated steel webs, most of the research think that the whole shear is born by the corrugated steel webs while the concrete roof and floor not participating in, which is different from the actual stress state of the structure. The paper reling on the Yellow River Bridge across the embankment on Wuxi Highway will study the shear transfer efficiency of the corrugated steel webs with the built model, the main contents and conclusions are as follows.1. Summarizes the development of composite beams with corrugated steel webs, overview the related research at home and abroad，the foreign research focused on aspects of corrugated steel web shear buckling and ultimate bearing capacity, while the domestic research focused on the study of static characteristics giving some qualitative description about its shear transfer, however, most of these studies are aimed at simply supported bridges with equal cross-section and small span, the study on continuous long-span bridges with variable cross-section is lacked.2. Combined with the Yellow River Bridge across the embankment on Wuxi Highway, the model of the relied project is built by Midas/Civil and Midas/FEA, the results shows that there is not much difference between the two models which can be later used in the analysis of the shear transfer, comparing their results under its own weight and prestresses.3. Based on the Midas/FEA model, the shear transfer of the concrete roof and floor and corrugated steel webs on the representative cross-section is analyzed under three conditions, which refer to the weight alone, the weight and prestresses occur simultaneously, as well as fully covered live loads on the deck. Data shows that the additional shear stress generated by the bending and shear under variable cross-section effect is large, resulting in an change in shear stress distribution of the beam which shows the shear born by corrugated steel webs declines while other shear born by concrete increases when the corrugated steel webs becomes high, this phenomenon has a big difference with the simply supported bridges with equal cross-section.4. The shear stress formula of the box girder bridge with variable cross-section is derived, and it is proven correct by comparing to the results of the FEA model and cross-section shear stress formula.