Date of Award

January 2022

Document Type


Degree Name

Master of Science (MS)


Civil Engineering

First Advisor



Thin-walled circular steel tubular columns have been used as bridge piers widely around the globe because of their excellent seismic performance: ductility, strength, and energy dissipation capacity. This thesis investigates the inelastic behavior of thin-walled circular steel tubular columns with a uniform section and thin-walled circular steel columns with diaphragms. The loading protocol considered for this study is either pushover or cyclic lateral loading in the presence of a constant axial load. The effects of a pushover and cyclic lateral loading on the behavior of the thin-walled circular steel tubular bridge piers have been evaluated through analysis of failure mode, hysteresis curve, envelope curve, stiffness and strength degradation characteristic, and energy-dissipating capacity, including interaction effects of local buckling and flexural buckling, and post-buckling regimes. The analysis applies the finite element model (FEM) that considers the effect of both material and geometric nonlinearities. Also, in this research a comprehensive parametric study was carried out to investigate the effects of the key design parameters and namely are: the radius to thickness parameter (Rt), the column slenderness ratio parameter (λ), and the magnitude of axial load (P/Py). Finally, a series of proposed formulae for strength and ductility evaluation for thin-walled circular steel tubular columns are given.