Studies On Out-of-plane Stability And Design Of Tubular Trussed And Solid-web Section Arches

Until recently, tubular trussed arches and solid-web section arches have beenwidely used in practice. However, out-of-plane stability theory has not been fullystudied, and out-of-plane design method has not been estabilished. This paper isconcerned with the out-of-plane elastic buckling and inelastic strength of tubular trussedarches and lateral braced solid-web section arches, and design methods for out-of-planeinelastic stability of the two types of arches are presented.Out-of-plane stability theory of steel tubular trussed arches is more complex thanthat of solid-web one because of the propertities of latticed sections. Shearingdeformation of latticed sections is involved in the study of out-of-plane buckling loadsof tubular trussed arches. Futher, geometrical nonlinear and material inelsatic behaviorof tubular trussed arches subjected to uniform compression or uniform bending isinvestigated respectively, and the corresponding design equations are obtained byemploying the normalized slenderness of tubular trussed arches. Effects of individualcomponent deformation on the out-of-plane strength of tubular trussed arches aresubsequently studied and they are reflected further in the design equations by twoparameters. Tubular trussed arches subjected to full-span uniformly distributed loads orhalf-span uniformly distributed loads are studied. Based on FE numerical results, theinteraction equations for the out-of-plane strength of tubular trussed arches undercombined load types are proposed. These interaction equations can be used for theout-of-plane strength design of tubular trussed arches with rectangle section or trianglesection.Based on the early buckling study of lateral braced columns, out-of-plane elasticbuckling and inelastic strength of lateral braced solid-web section arches areinvestigated by energy approach, and a close solution for elastic or inelastic thresholdstiffness of lateral bracings is proposed. Out-of-plane buckling loads of arches withelastic ending restains are obtained firstly. After that, for solid-web section arches withnon-uniformly distributed lateral bracings, elastic end restraints resulting from adjacentarch segments are considered in the out-of-plane buckling analysis of an intermidatearch segment. Effects of initial geometric imperfection distribution on the out-of-plane inelastic strength are studied subsequently. The most detrimental geometricimperfection distribution resulting in the lowest out-of-plane inelastic strength isobtained and proposed theoretically. And the inelastic design method of lateral bracedarches and the principle of the arrangement of lateral bracings are proposed.A test device is proposed to study the out-of-plane inelastic stability of steel arches,and nine specimens are designed and tested to investigate the effect of boundaryconditions, section types, rise-to-span ratio, slenderness ratio and out-of-planegeometric imperfection of arches as well as in-plane loading types on the out-of-planeinelastic strength of arches, and conclutions obtained by test are verified by finiteelement method. The results obtained by tests may supply the reliable verification forthe out-of-plane inelastic design of steel arches.