In-plane Stability Of Parabolic Concrete-filled Steel Tubular Arches

The concrete filled steel tubular (CFST) arches have obtained a wideapplications in bridge engineering, large-span stadium pavilion and the subwaytunnel excavation due to its pleasing aesthetic, convenient construction process,high spanning ability and high compressive strength. The CFST arch bridges are themost representative application, and have been developed rapidly in recent20yearssince WangCang bridge being bulit as the first CFST arch bridge in China in1990.More than300CFST arch bridges have been built till now according to incompletestatistics, with about40bridges spanning more than200meters, and the maximumspan of the CFST arch bridges is longer than500meters. With the development ofCFST arch bridges, new construction technology and new types of bridges appeared.However, compared with such a wide usage, the design guidance is yet to bedeveloped. Thus, it’s necessary to investigate the mechanical behavior of CFSTarches. This paper is intended to investigate the in-plane stability of parabolic CFSTarches, and the following parts are concluded:(1) Finite element modeling and verificationIn this chapter, a nonlinear finite element model is built using ABAQUS anddescribed in detail, including the stress-strain relationships, element types andgeometric imperfections. In addition, the FE model is verified with testresults.obtained from previous CFST columns tests and CFST arches tests.(2) In-plane stability of CFST parabolic arches subjected to axial compressionThe in-plane stability of CFST parabolic arches that are subjected to axialcompression is investigated considering both geometric and material nonlinearities.The key issues including rise to span ratio, slenderness, steel proportions are takeninto account. A new slenderness reduction factor is proposed to predict the in-planestrength of CFST parabolic arches subjected to axial compression. This factor isconsistent with the Chinese steel structures design code GB50017.(3) In-plane stability of CFST parabolic arches subjected to typical verticalloadingsIn design practice, the parabolic arches are mainly subjected to differentvertical loadings, where both the axial compression and bending actions aredominant internal forces. Thus, four typical vertical loading types are selected andinvestigated in this chapter to obtain the buckling behaviors of CFST parabolicarches subjected to combined axial compression and bending actions. The keyissues including rise to span ratio, slenderness, steel proportions are taken into account. A moment-correct coefficient is proposed to predict the in-plane strength ofCFST parabolic arches subjected to combined axial compression and bendingactions.