Experimental Investigation into In-plane Stability of Concrete-Filled Steel Tubular Parabolic Arches Under Five-Point Concentrated Loads

This paper deals with experimental investigations into in-plane stability of fixed concrete-filled steel tubular (CFST) parabolic arches. Three CFST arches with the same span but different rise-to-span ratios were tested under five-point symmetrical concentrated loads over the full span. All applied loads were controlled in synchronization. The test results show that the test arches buckled in an antisymmetric failure mode and the section positions with the maximum deformation were slightly different for three test arches. It is found that the bearing capacity of CFST arches decreased significantly with the decline of rise-to-span ratios, and the outer steel tube provided significant confinement effects on the core concrete after the load reaches 80% of the load-carrying capacity. Moreover, comparisons between the test and finite element results indicate that the existing beam-element modeling method can predict the in-plane stability performance of CFST arches very well.