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Abstract: In horizontally curved steel box girder bridges, large relative displacements between box girders and individual girder rotations may occur during the deck pouring operation. Installing intermediate external cross-frames between box girders is perceived to be an effective means to control these displacements. However, it is imperative to minimize the number of such cross-frames, as these external cross-frames are not only expensive but also have adverse consequences for the fatigue characteristics of the steel box girders. A new parameter, deck unevenness ratio, was defined in this study to quantify the degree of uneven deck caused by relative deflections and rotations. In order to assess the effects of external cross-frames on the deck unevenness ratio that affect deck slab construction, a number of hypothetical twin-box girder bridges were analyzed for this study using a commercial finite element program, ABAQUS. The conventional method and Wisconsin DOT deck pouring sequences were compared for three-span continuous curved bridges. [Copyright &y& Elsevier]

Abstract: An efficient finite segment method for the analysis of curved box girders with corner stiffeners is presented in this paper. By modeling the deck of a curved box girder with modified curved beam element, using normal curved beam element for modeling the bottom plate, the webs and the corner stiffeners, a spatial displacement field is constructed for the analysis of a curved box girder. Thus the shear lag effect and local flexural behavior of the deck are taken into consideration in constructing the displacement field as well as the stiffness of the corner stiffeners. The formulation of the finite segment is developed based on the variational principle. The major advantage of the proposed approach, in comparison with the finite element method, is that it can simplify a three dimensional structure into a one dimensional structure for structural analysis, which results in significant saving in computational efforts. The effect of the stiffness of the corner stiffeners is taken into account in the analysis conveniently. Numerical example is given to illustrate the application of the proposed approach. It is shown that the effect of the corner stiffeners should not be ignored in the analysis of curved box girders. [Copyright &y& Elsevier]