Rational Completion Stage And Parameter Optimization Of Extradosed Cable-stayed Bridge

With the development of the bridge technology, many new bridge types have been constructed in the world.'This bridge type is a hybrid between a cable stayed bridge and a girder bridge so as to extend the span range of the girder bridge. The extradosed cable-stayed bridge, considered as a new type of structure, has been rapidly developed and extensively applied recently because of its advanced structural function and economy. Some researches on this kind of bridge type were done.It is a key problem to determine the reasonable cable forces in designing cable-stayedbridges, and the design of cable stayed bridge is usually started on determining a reasonable complete status of the structure. There are several methods to determine a reasonable completed status of prestressed concrete cable stayed bridge and each one have good and badsides. On the basis of analyzing and generalizing the former researchers' achievements, the zero-displacement method combined with stress balance method is adopted to determinethe reasonable cable forces in the paper.Based on the established finite element model, the effects with different structural parameters (the support conditions, the height of pagoda, the length of non-stayed cable segment and the ratio between the side span and the main span) on the structural internal force and deformation are analyzed and the reasonable values of the height of pagoda is obtained.Considering the former research,a new design method for extradosed cable-stayed bridges is suggested which is compared with the tradition design method.