The Study Of Stability And Ultimate Load Carrying Capacity Of Long-Span Steel Arch Bridge

With the increase of the span of the arch bridge, the stability problem becomemore and more evidence and become one of the most important control factor of archbridge design. This paper basese on the xinguang bridge , through processingstability analysis ,and discusses all kinds of factors affecting the stability of long－span steelarch bridge and provides profitable suggestion for desigen of the same kindof bridge. Stability problem generally is divided into two sorts.The first type comes downto evaluate eigenvalue problem,whichis easy to be calculated,due to the effect of thematerial nonlinear,geometry nonlinear and original bug ,the second kind stability isultimate load carrying capacityproblem which is more reasonable comparing to thetrue result.The existing theory is my paper's guidance,considering both of theeigenvalue stability and ultimate load carrying capacity,I use finite element method,analysising the braceing style and layout's influence upon stability of arch bridge,intensity of deck's influence upon stability, arch rib obliquity's influence uponstability and ultimate load carrying capacity of arch bridge,transverse wind load'sinfluence upon ultimate load carrying capacity of arch bridge. The result of the calculation indicates that stability satety coefficient usingnonlinear stability analysis method is far lower thanthe result of eigenvalue bucklinganalysis method due to the influence of material nonlinear,eigenvalue bucklinganalysis may induce non-conservative result;The "一"style braceing is adapt to setupon the top of arch and "K"style braceing is adapt to setup on the 1/4 span and near ofthe top of arch;Due to the influence of non-keep-direction force,with the increase ofrigidity of deck ,the lateral stability of arch bridge will be enhanced;With the increaseof arch rib obliquity ,the linear stability coefficient will increase,but it will decreasethe ultimate load carrying capacity;Transverse wind load will greatly reduce theultimate load carrying capacity,it is necessary to verify the stability of wind duringbridge construction.