Spatial Analysis Of The Prestressed Concrete Curved Bridge

It is very complicated to analyze prestressed concreted curved box girder due to many factors such as tendon, bending, torsion , shear lag and wrapping.Based on the other's research, a practical prestressed concrete curved box girder bridge model is selected to perform investigation of it's spatial mechanical characteristics.3-D isoparametric elements and virtual lamina elements are used to simulate the cuvred bridge, and equivalent node load is used to simulate the effect of prestressing force . Results show that prestressing force can efficiently resist the bending stress. However, it will increase the torque of curved bridge, thus, it is necessary to adjust the disposal of the prestressing tendons. Further study of some other factors of the curved bridge show that different tensioning sequence will influence the stress state obviously;The radius is a very important factor in curved bridge, it is advantageous to the bridge as the radius increase. And the temperature gradient can strongly influence the stress state of roof and bottom slabs of the box girder. As a spatial structure , 3-D finite element analysis is recommended in this subject. Finally, the author has analyzed the ultimate bearing capacity of the bridge which is based on the others' study in nonlinear theory of prestressed concrete bridge, with the description of the failure characteristics, and results are compared to the national design code, some suggestion is made, which are of relevant significance to structural design.