Research On Nonlinear Behavior During The Construction Process Of Long-span Rigid Frame Bridges With High Piers

With the rapid development of China's transport, more and more long-spanbridges with high piers have been emerging in recent years. Owing to the main beamand the formation of the upper frame structure bearing the load, on the one hand, themain beams bears pressure reasonably, on the other hand, piers in the structure arefull of potential, so continuous rigid frame bridge in China has been widely used andhave developed quickly. With continuous rigid frame bridge's span becoming larger,the pier height increasing, and nonlinear effects become more and more evident, moreand more experts and scholars have become more and more concerned about thisproblem.This thesis relying on a typical long-span continuous rigid frame bridge withhigh piers——Wang Jia Ba Bridge construction as a monitoring project, has studiednonlinear behaviors during the construction of long-span continuous rigid framebridge with high piers, summarized the influence rules of the internal force andelevation in the construction process, which are caused by the nonlinear, focused onthe pier stability in cantilever construction process, which is also affected bynonlinear, and summed up the universal law.Firstly, this thesis has described the causes of all kinds of nonlinear problems inthe structure of the bridge and nonlinear problems solving methods and steps, studiednonlinear stability in the construction process, and summarized some of the nonlinearequations methods. Secondly, using a bridge analysis software Midas/Civil, thisthesis has done a simulation analysis of the bridge construction phases. Comparedwith the calculations of taking into account nonlinear and not considering nonlinearduring the construction phase, this thesis has drawn the regular influence law of theinternal forces and elevation by the nonlinear during the high pier cantilever spancontinuous rigid frame bridge construction process; By comparing the theoreticalcalculation considering nonlinear stress and the stress live measurement results, thisthesis has obtained the influence of the internal forces by nonlinear factors on the bridge construction process. Finally, using ANSYS software, the model of the highestpier body construction phase, the model of the maximum pier largest cantileverbridge construction phases and the model of the phases into bridge model have allbeen established, and they were all simulated by adopting different units, this thesishas got analysis and comparison of the eigenvalue stability and nonlinear stabilityunder the various construction stages, so it can offer information and reference for theconstruction and design of the same type of bridge.