Experimental Investigation Of The Model And Analysis On Curvilinear Bridge With Boxed Cross-section

Because of construction of city bridge in recent years, curved bridge structure are already adopted in China. And the section of structure is box type in the most of curved bridge .By the influence of curvature, it lead to bending and torsion deflection , warp and aberration, even if outer load(the deadweight of main girder and the weight of cradle) effect on the shear center of the beam. In the cantilever construction, except for bending deflection, the deadweight of main girder and the weight of cradle lead to torsion deflection. In the course of stretching tendon, the effect of prestressed tendon that lead to beam end horizontal deflection and torsion is undeterminable. So this make complexity of curved bridge mechanical analysis. And the difference of stretching sequence of prestressed tendon will influence the beam end torsion.The engineering lie in the circular curve and adopt cantilever cradle laying construction. It's 3 spans prestressed continuous beam bridge with varible section. It spans 72 meter and 110 meter and 72 meter. The section of this bridge is single cell box. The height of the beam and the thickness of the backplane will take circular curve.Though curved bridge and cantilever construction are ripe as single technology. But the computing method and criterion are little refered in the literature. Based on computational theory of arch bridges, finite element and similarity theory, this paper has put emphasis on model test and theory analysis of continuous curved bridge. The detail as the following:Based on similarity theory of model test, the space Perspex model for the global structure is established. Under the condition of the experiment effects, the actual bridge is computed by FEM plane frame. Also the measuring point and load case are defined. Under every kind of load case, the strain and deformation of critical sections are compared between experiment and numerical solutions. The structure check coefficient is computed .And it analyze the influence of cantilever laying process and stretching tendon as to cantilever constmction. According to the computing results, some helpful suggestions are drawn for other similar bridges.A space FEM model is established with MIDAS/Civil software. Then the result of the model is checked by ANSYS. The deflection are computed with MIDAS software, and the computing result is compared with that of simplified model of FEM plane frame. And it analyze the inaccuracy of the model of FEM plane frame for this bridge.