Study On Mechanical Properties Of Prestressed Concrete Continuous Curved Box Girder Bridge With Large Span And Small Radius

The curved beam bridge usually refers to the beam bridge with the design axis as a curve.The appearance of the curved beam bridge is the inevitable result of the development of the bridge design.Since the reform and opening up,curvilinear bridges have begun to emerge in large numbers in China's coastal areas and many developed cities.Under the background of the increasing construction of national transportation construction,curved beam bridges have become the most important bridge construction due to their strong traffic capacity and beautiful visual effects.With the deepening of people's understanding of the curved beam bridge and the continuous increase of urban traffic flow,engineers hope to further increase the span of the curved beam,increase the curvature,increase the bearing capacity,and increase the stability.In this paper,I established a large-scale indoor small-radius long-span prestressed curve beam bridge model under the existing conditions,its scale exceeds other previous indoor model test,the model has more than 180 test points arranged with more than 40 loading conditions.In this paper,under the action of load,temperature and three-dimensional prestressed loads on the curved girder bridge,the bearing reaction force of the structure,the vertical and horizontal deformations and the strain and stress effects of the control sections were tested.And the cause and mechanism of the test phenomenon were analyzed.For some experimental phenomena,some practical suggestions have been made.It is suggested that a certain lateral camber should be set on the basis of the super high value of the structure.The best time for removing the scaffold in the project is daytime sunlight under high temperature season.Under the support of model tests,this paper uses the Midas civil finite element program to establish a 7-DOF space bar model,a 7-DOF space beam grid model and a 6-DOF space plate unit model.Combined with the experimental test results,the bending and torsion effects of the small radius curve beam under various load conditions are systematically analyzed,the distribution law of the principal stress of the curve beam is explained,and the effect of three directional prestressing on improving lateral bending and vertical shear capacity is demonstrated,the reliability of the test data and the accuracy of each finite element numerical modelis verified.This can provide reference for the future model test study,and at the same time provide a method for the selection of the calculation model for the design of small radius curve bridges in engineering.