The Study on the Effect of the Lateral Braces on the out-of-Plane Stability of Web Openings Circular Steel Arches

The paper adopts large deformation elastic buckling finite element method, researches the out-of-plane stability of lateral braced web openings circular steel arches under the distributed radial load and considers the effects of rise-span ratio, arch foot condition, brace rigidity and brace quantity. Research results demonstrate that the out-of-plane buckling load of web openings circular arches increases with the rise of rise-span ratio and increases with the improvement of arch foot constraint. Buckling half waves increase gradually with the increase of lateral brace stiffness. When brace stiffness reaches the brace critical stiffness, the out-of-plane buckling load of steel arches increases will no longer increase with the rise of the brace stiffness, and the buckling mode of steel arches will transit from out-of-plane instability to in-plane instability. The improvement degree of lateral brace to the bucking load of web openings circular steel arches depends on the lateral brace quantity and the size of the brace intervals.