Butterfly-shape Stress Region and Its Rebar Optimization in Anchorage Zone of Main Girder of Large-span Curved Extradosed Cable-stayed Bridge
In order to explore the influence of bending torsion coupling effect on the local anchorage zone of the main girder of the curved low tower cable-stayed bridge,and optimize the local reinforcement scheme,taking Wangjiahe Bridge as the background,the segmental models of straight bridge and curved bridge were calculated and compared in terms of stress,deformation and prestress efficiency under completed and the maximum cantilever construction conditions.The butterfly-shaped shear stress concentration region of the anchoring zone caused by flexural-torsion coupled effect was proposed.The results show that the flexural-torsion coupled effect increases the principal tensile stress of each part of the main girder in the anchoring area.Meanwhile,the flexural-torsion coupling significantly increases the area of butterfly-shape shear stress concentration region by nearly 40%.The asymmetric reinforcement scheme can be adopted,and the proportion of shear reinforcement on the bending side of the curved bridge anchorage should be increased appropriately.The flexural-torsion coupled effect remarkably increases the transverse displacement of the anchoring part of the main girder by near 30%.Conversely,it has little effect on the deflection of bridge.The efficiency of prestressed application in the anchorage zone of the main girder is slightly improved under the coupling effect of bending and torsion,which should be taken into account in the calculation of beam configuration.
NETL
NSTL
万方数据
