| The PC composite box girder bridge with corrugated steel webs has been widely used home and abroad by means of its structural advantage and good mechanical behavior. Replacing the concrete webs with corrugated steel webs is the unique feature of this sort of bridge. Therefore, the key to the construction is to ensure the force, distortion and stability of webs that can accord with the requirements. Based on a certain large bridge with corrugated steel webs, this thesis mainly focuses on the following aspects, using Midas/civil to simulate the construction process and using Ansys to analyze stability parameter of the webs.(1)Analyze the force in construction stage with Midas/Civil to establish spatial finite element model, ensuring that materials' intensity fits the designing requirement in construction stage without any buckling.(2)Work out the precamber of the whole bridge according to the computing results of models.(3)Control the initial tensile stress of the internal prestressing tendon and external prestressing tendon and analyze the effect that different proportions in external beam exerting on the force and distortion of the whole bridge.(4)Control the parameters like web thickness, girder height, straight segments length, wave height and obliquity. Establish several finite elements models of box girder with corrugated steel web and carry out eigenvalue buckling computation. Count a certain part of distortion of eigenvalue buckling first—order modal computing results into initial geometrical defect of nonlinear analysis. Take the effect of material nonlinear and geometrical nonlinear into consideration and carry out buckling corresponding analysis with arc—length method to elicit relative load—displacement curve and nonlinear buckling intensity value.(5)Compare the computing results of models with computing results in theoretical formula, analyze applicability and reliability of theoretical formula and research on the effect that post—buckling intensity exerts on the structure.Following conclusions are made through the analysis:(1)PC composite box girder bridge with corrugated steel webs resembles the conventional continuous bridge in the aspect of force in the cantilever construction stage.(2)Reasonably increasing the proportion of external prestressing beam is beneficial to optimize structural force and reduce interference in the span.(3)The increase of thickness of webs and angles can effectively improve shear buckling load of webs; the increase of height of webs and straight segments length can reduce the ability of bearing the external load; the increase of wave height in a certain scope can effectively increase shear buckling strength while the loading capability can be reduced with subsequent increase of wave height.(4)Thickness of webs, straight segments length and height of webs have less impact on the shear buckling intensity of corrugated steel webs while obliquity exerts obvious influence. If obliquity and wave height are increase at the same time, overall buckling may occur in corrugated steel webs. |
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