The Research On Stability Of Long-Span Continuous Rigid-Frame Bridge With Thin-walled High Piers At The Construction Stage

In the 21st century, owning to their advantages on economy and construction, long-span continuous rigid frame bridge with thin-walled high piers is commonly built in China with the development of Science & Technology and transportation enterprise. However, The geometrical nonlinear behavior of bridge becomes more and more important with the increase of its span and pier height, especially in the stage of maximum cantilever construction is more remarkable.Based on Lushuihe Bridge of Linchang highway under construction in Henan province, the research is developed around the long-span continuous rigid frame bridge with thin-wall high piers in the stage of maximum cantilever construction. The theory of bridge's stability is generally introduced in the first. Then contrapose to the structure of bar system, the geometrical nonlinear theory are discussed and the discrimination between Total Lagrangian and Updated Lagrangian Formulation in Lagrangian Formulation are emphasized. Finally, the solution of nonlinear equations and some kinds of the convergence criterion in common use are introduced.This thesis briefly discusses the temperature distribution theory of concrete box structure, the formation of sunshine temperature and its characteristics, and the basic characteristics of wind load, analyze the influence of the long span rigid frame bridge with thin-walled high piers in the stage of maximum cantilever construction on temperature effects and wind load. Adopting finite element program Midas/Civil, the geometrical nonlinearity stability of the maximum cantilever with this bridge is analyzed, taking into account the effect of static wind load and temperature effects, so as to evaluate the contribution of the geometrical nonlinearity to the stability. The conclusion can be made that constant load, construction load get up the control action and temperature load, wind load plays smaller action in the course of stability analysis.The results can make evaluation to the stability of the maximum cantilever construction and can also provide reference to the practice engineering through the analysis.