The Analysis On Key Techniques Of Rotation Construction Of Framework-Strengthened Concrete Arch Bridge

The bridge rotation construction technique is a method to move a pre-built bridge to its scheduled place. This technique has taken advantage of the geographic ?location to put up simple scaffolds along the river bank and prefabricate the large bridge beam structure, then a panel made up of hinge and slide way with small friction will be driven by some simple equipment to move the bridge beam around the tower to its scheduled place.It has a lot of outstanding advantages to combine rotation construction to frame-strengthened concrete-filled steel tube, such as lighter weight and higher strength, so that more and more rotation construction bridges have come out. So far it has been built more than one hundred multiform rotation construction bridges in our country. There are still many key problems to be solved, for example, it is needed too much time to produce grind centre and grind lid, it is difficult to calculate the reasonable cable tension and the structure may lose whole stabihty, so it is necessary to research on the key techniques of rotation construction of arch bridge.Firstly, the thesis describes the methods of making grind centre, grind lid, balance pier and the processing of steel framework, then analyses on the key techniques of grind centre and grind lid. Whereafter, the thesis improves the making method and structural forces of grind centre and grind lid based on the Dayandong Bridge.Secondly, an accurate 3-D space model is established with use of the FEM software MIDAS. And the internal forces and deformation as well as cable tension which rotation needed etc. of the structure, in pulling and swiveling stage, are analyzed. At the same time, the changing rules are summarized to forecast the stress and the displacement of essential sections of the Dayandong Bridge.Thirdly, in consideration of the whole stability of structure in pulling and swiveling for closure stage, the the critical load values and stabiiity safety factor of the framework are calculated, and the results show that the structure is safe relatively.Finally, the construction of the framework experiences three stages after swiveling for closure: formation of the rib, parts of the framework was wrapped by concrete and the stage of the whole framework was wrapped by concrete. The whole stability in these stages is not better enough, monitoring and controlling of the stress, strain and displacement to DaYanDong Bridge is absolutely necessary. Taking the Dayandong Bridge as an example, the supervision methods of construction and the theories of error analysis are expatiated.