The Study On The Effect Of The Lateral Braces On The Out-of-plane Stability Of Web Openings Circular Steel Arches

Currently, the steel arch with web openings has been widely used in buildingstructures, especially public buildings e.g. subway stations, stadiums, and airport terminals.Out-of-plane stability of steel arch with web openings is the most important controllingfactor in the design. Usually, in practical engineering, most people adopt the way of lateralbracing based on experience to ensure the out-of-plane stability of steel arch. However,current studies for this aspect are not enough. This paper mainly studies the out-of-planestability of steel arch with web openings that has lateral bracing.The paper uses the Finite Element Method (FEM) to study the out-of-plane stabilityof steel arch with web openings that does not have lateral bracing. It analyzes how theout-of-plane buckling critical load of steel arch varies with central angle, slenderness ratioand skewback condition under the acting of uniformly distributed radial load and equalreverse end-moment. It obtains the change law of the out-of-plane buckling critical load ofsteel arch and points out the reasons why the change laws of the out-of-plane bucklingcritical load are different under different loads and skewback conditions. It studies theeffects of horizontal uniformly-distributed vertical load, uniform vertical load that actsalong axis and concentrated load that acts on arch on the steel arch. It takes into accountthe impacts of the above three conditions, obtaining the change law of buckling criticalload under the acting of different vertical loads and pointing out the optimal rise-span ratioof steel arch.On the basis of above studies, this paper studies the out-of-plane stability of steel archwith web openings that has lateral bracing and points out the importance of bracing typefor improving the out-of-plane stability of steel. It considers the changes in brace stiffness,braces amount and skewback condition, obtains the change law of the out-of-planebuckling deformation of steel arch, and points out the factors that affect the criticalstiffness of lateral bracing of steel arch. In the case of completely effective bracing, itstudies the out-of-plane buckling performance of steel arch under different vertical loadsand gets the law of how buckling critical load of steel arch changes with bracing amount.Under the acting of horizontal uniformly-distributed vertical load and through fitting thelarge amounts of the results of finite element calculation, it obtains the distance formula of stability design that acts on axis between lateral bracing points.