Seismic performance and collapse prevention of concrete-filled thin-walled steel tubular arches

The primary objective of this paper is to investigate the seismic behaviour of concrete-filled steel tubular (CFST) arches using incremental dynamic analysis (IDA). A nonlinear elastic-plastic finite element model is developed using OpenSees software and is verified with a shaking table test. Single-record IDA studies indicate that a CFST arch undergoes global dynamic instability when subjected to ground motions of increasing intensity levels. During this process, either dynamic elastic buckling or dynamic elastic-plastic buckling may occur. Dynamic strength, which is defined as the capacity for preventing global dynamic instabilities of CFST arches, is determined with a series of multi-record IDA calculations. A lower bound equation that takes into account the effect of slenderness ratio, axial compression ratio, and included angle is proposed for the prediction of the dynamic strength of CFST arches.