The Spatial Analysis Of PC Curved Box-girder Bridge

In recent years, PC curved box-girder is applied more and more in construction of express high way and grade-separation bridges for its economy , fine figuration and favorable construction methods. However, people met with a lot of difficulties. The complexity of PC curved box-girder bridge lies not only in its mechanical features but also in other fields, compared with straight one.In the paper, spatial curved-girder element and straight-girder element are analyzed by finite element method for longitudinal and transversal members of grillage, considering six degrees of freedom per node, and the module for grillage static analysis is formed. And at the same time, it discusses how to divide the grillage, how to calculate the constants for longitude beams. Compared with the results of SAP90, it has been discovered that the grillage analogy method has enough accuracy to satisfy the demands of designing if the designs are made following the method given in this paper. The structural model is defined by the dimensions of control sections, while the tendons are described by a segmental fit model, and equivalent loads of tendons is introduced, which can be used for both straight and curved bridges.At last, examples presented show the validity of the theory, the arithmetic and the given programs.