Battened Thin-Walled High Pier Stability Analysis Of Long Span Continuous Rigid Frame Bridge At The Construction Stage

With the development of freeway in china especially westward, the continuous rigid frame bridge with high piers is built extensively due to complex landform, convenience construction, economy and application. It is similar important to study the stability and the strength of the fabric with high piers. Taking the Longtanhe Bridge on the Yichang to Enshi section of Hurong Freeway as the background engineering, the stability of strctrue with construction stage is studied in this thesis. The main research work is summarized as follows:(1) This thesis introduces the phylogeny, research and application actuality inland and abroad of the stability of high piers. The first and the second kind stability theories are described. The first-order buckling formula is deduced through energy method.(2) Adopting the Beam44 of the common structure analyses procedure Ansys, the first-order linear elastic stability in representative work conditions of the Longtanhe Bridge are analysed, which include the highest pier, the maxium cantalever and the fulfilled bridge. Based on the parametric analysis of the 130m pier temporary timbering at the construction stage, rationality of the design is discussed and some standpoints are presented.(3) Adopting the Solid45 of the common structure analyses procedure Ansys, the geometrical nonlinearity stability of the maxium cantilever with the Longtanhe Bridge battened thin-walled high piers is analysed, taking into account the effect of static wind load and the initial flaw of sunlight temperature difference and construct duration., which comparing to the results of the linear elastic stability so as to evaluate the contribution of the geometrical nonlinearity to the stability.(4) Adopting the Solid65 of the common structure analyses procedure Ansys, the behavior of the 130m and the 178m battened thin-walled high piers in the maximum cantilever work condition of Longtanhe Bridge are analysed, considering the effect of the material and geometrical nonlinearities, the initial flaw and the wind load. The safety stock which coincides with the practical situation is obtained. Comparing to the results of the linear eastic and the geometrical nonlinear stability, the conclusions are achieved such as the effct of the material nonlinear on the structure, the safety stock of the structure stabilization in the worst-case condition, which provides valuable reference to the engineering practice.