Study On The Stability Of Steel Arch In Construction

Steel arch in the country experienced decades of development, its span isincreasing, and played an extremely important role in the bridge construction. Steelarch is a frame structure composed of a number of slender rods made. Due to its safe,reliable, convenient assembly，reasonable structure, high intensity, short constructionperiod，it has been widely used in practical engineering. It is an important tool in thecourse of bridge construction. Because of the need to adapt to the structural designand construction, the steel arch in the decades goes through continuous optimization,and comes in many forms, including bailey beams steel arch railway,military beamsteel arch, fine-tune the steel arch, etc.With the continuous development and progressof science and technology, the improvements of the structural properties of thematerial，the stability of the structure becomes more and more prominent, due to itssmall structural rigidity with span growing increasingly. In the design, the stability ofthe structure are equally important with the structural strength. This paper mainlystudies the stability of frequently used railway military beam steel arch, to provideguidance for future applications in engineering practice.In this paper, the frequently used steel arch of Zhengzhou bridge expansionproject in Qianjiang District is used as the research object and use MIDAS/Civillarge finite element software to establish the spatial structural model,calculate criticalelastic buckling load,geometric nonlinearity stable load with different parameters andanalyze their impact on critical elastic buckling load. This paper works from thefollowing aspects:①The relationship between steel arch elastic buckling load and the number ofthe triangular units of steel arch;②The relationship between steel arch elastic buckling load and boundaryconditions of steel arch;③The relationship between steel arch elastic buckling load and temperature④The relationship between steel arch in-plane buckling elastic buckling loadand out-of-plane buckling elastic buckling load;⑤The relationship between steel arch elastic buckling load and the connectionmethod of the steel arch triangular units;⑥The relationship between steel arch elastic buckling load and pieces of steel arch;⑦The relationship between steel arch elastic buckling load and the distancebetween the piece and the piece of steel arch;⑧The relationship between steel arch elastic buckling load and the number ofpieces of steel arch;⑨The relationship between steel arch elastic buckling load and no initial defectgeometric nonlinearity;⑩The relationship between steel arch elastic buckling load and initial defectgeometric nonlinearity.Due to the method of construction of concreting by layer and layer and bysegment and segment often used for long-span arch bridge, steel arch and concretepoured into the ring work together for the stability, and analyze the steel arch stabilityvariation in the construction process to make real scientific evaluation of the stabilityof the construction process.Through the work summarized above,this paper draw some useful conclusionsproviding guidance for future similar projects.