The Study On The Twice Vertical Swivel Technology Of Stiff Skeleton Arch For Lancang River Bridge And The Response Analysis For Bridge Structure

The Lancang River Bridge, a deck arch bridge reinforced with concrete-filled steel tube arch bridge located in Dali-Ruili Railway, are342m long of the main span. The main arc turned into a single cell and single box section of the main arch structure by filling and outsourcing concrete, as with the two times Vertical swivel construction method to make the concrete filled reinforced truss in place. To secure the construction process and satisfy the research requirement for this project, this thesis studied the safety of the two times Vertical swivel construction process and nonlinear seismic property of this bridge, which are discussed in detail as follows:1. This thesis analyzed the static property of the arc in seven typical locations when doing two times Vertical swivel allowed for the dynamic coefficients in the construction process, which inferred that the swivel process was safe as the stresses were under the allowed level.2. This thesis analyzed the construction process of the main bridge considered the techniques of swiveling the reinforced framework and the multi-working face and four rings construction method and compared the results with those used the two times vertical swivel method, once vertical swivel method and once frame located method. The force of the structure were nearly the same with several previous construction method and the stress of the steel box safe capacity were enough as the bridge are both in construction process and in service.3. The dynamic analysis of bridge based on a finite model with multi RIZE vector method considered the bridge approach inferred that the rigidity of the bridge are larger than similar ones.4. This paper discussed the geometrical nonlinear effects of the bridge vibration characteristics, deformation and internal force of impact. The results showed that frequencies reduced, the internal forces and the deformations were all increased in consideration of the geometrical nonlinearity, but the effected value is small, which can be neglected on earthquake resistance of bridge.5. The structure response under the action of frequent, design, rare earthquake wave was analyzed respectively based on linear elastic theory and material nonlinear theory. The comparison of the results showed that the outsourcing turns into plastic quickly, and the concrete filled turned into plastic under the action of the design and rare earthquake wave, while the steel skeleton kept elastic under each kind earthquake. Compare with the linear analysis, the influence of considering the material nonlinearity to the seismic response is negligible.