Study On The Stability Behavior Of Cable-arch Structures

Arches are widely used in bridge engineering and structure engineering for theirbeautiful shape, large rigidity and good economic gains, etc. However, slender archessubjected to both bending and compression are easy to buckle. In order to improvethe stability behaviors of arches, a new type hybrid steel structure named cable-archstructure appears in recent years. This structure combines the arch and the tensilecables into an integrated structure system, which can fully utilize the advantages ofthe tensile cables and the arch. The deformation of arch in cable-arch structures isgreatly restrained by cables, so that the stiffness and ultimate load-carrying capacityare significantly improved.According to different arrangements of tensile cables, the styles of cable-archstructures are various. In this paper, two types of cable-arch structures are selected fordetailed investigation. For the first type, cables are arranged according to the bendingmoment diagram of the pure arch subjected to the uniformly distributed vertical load.For the second type, cables are arranged according to the bending diagram ofthree-hinge arch subjected to the half-span uniformly distributed vertical load.In order to investigate the stability of the first type cable-arch structure, thebending moment distribution of pure arch subjected to the uniformly distributedvertical load is firstly analyzed in this paper to determine the arrangement of cables inthe first type cable-arch. Then both elastic and elastic-plastic stability of the first typecable-arch subjected to the full-span and the half-span uniformly distributed verticalload are investigated, and are compared with the stability behavior of pure arches.Moreover, the effects of structural parameters, including cable section area, bracelength, prestress in cables and so on, are comprehensively analyzed in order to revealthe mechanical behavior and the failure mechanics of the cable-arch structure. Finally,the sensitivity analysis of initial crookedness for this type of structure subjected to thefull-span uniformly distributed vertical load is discussed.Before the investigation of the behaviors of the second type of cable-archstructure, the static behavior of three-hinge arches is analyzed. The elastic andelastic-plastic stability behavior of the three-hinge arch with different rise-to-spanratios and differtent hinge positions under different load case are analyzed.Meanwhile, the deformation and bending moment distribution of the three-hinge archare also analyzed in this paper to guide the following investigation of behaviors of thesecond structure. The elastic and elastic-plastic stabilities of the second cable-archstructure subjected to the full-span and half-span uniformly distributed load areinvestigated by changing the rise-to-span ratio and the hinge position, and theoptimum hinge position are achieved from the analysis results.In summary, this paper investigates the elastic and elastic-plastic stability of twotypes of cable-arch structures subjected to different load case by numerical analysisapproach, and discusses the effects of structural parameters on the stability behaviorof structures. Some conclusions drawn from this research are valuable for the analysisand design of such structures.