Abstract
In order to investigate the seismic behavior of the hollow circular RC piers having reinforcement cut-off planes and variable wall thickness and to examine the effect of the strengthening with carbon fiber sheets for the improvement of seismic performance, static and pseudo-dynamic tests using elaborately modelled specimens were carried out. From the experimental results, it was verified that the unstrengthened specimens were sound and well designed under the conventional design earthquake. It was shown that the specimens failed in shear when a severe earthquake which was several times as great as the design earthquake applied and that the seismic performance of the specimens were sufficiently improved by strengthening with carbon fiber sheets. Furthermore, it was found that the reinforced concrete hollow circular cross section had a specific mechanical characteristics under the severe seismic forces.
