Experimental investigation into the in-plane buckling and ultimate resistance of circular steel arches with elastic horizontal and rotational end restraints

This paper presents the experimental and simulation study of circular steel arches attached on the steel columns through the rigid connection, which are loaded to failure under static load. Local buckling of the top flange at the mid-span arch or the bottom flange at end of the arch occurs under the ultimate load. The deformation shape is approximately antisymmetrical with a 0.2 rise-to-span ratio and is symmetrical with a 0.1 rise-to-span ratio. A simplified model is proposed as an arch with elastic horizontal and rotational end restraints. The corresponding stiffness is determined as equivalent horizontal and rotational stiffness at each arch end under the ultimate load. Then a large amount of parameter analysis is conducted to investigate the influence of the elastic supported stiffness, load type, rise-to-span ratio, and slenderness on the ultimate resistance. The finding is that the reduction of the ultimate resistance for the arch with the horizontal and rotational elastic end restraints is maximal under the uniform full-span vertical load, minimal under the concentrated load. Finally, a design method of the steel arch with elastic horizontal and rotational end restraints is proposed taking both ultimate resistance and maximum horizontal displacement of the supports into account for engineering reference.