Unembedded type column bases in SRC buildings were damaged by Hyogoken-Nanbu earthquake. It is thought that the tension forced due to overturning moment is the reason why these damages. Over the past few years after Hyogoken-Nanbu earthquake, several experimental studies have been carried out on seismic performance of the Unembedded type column bases under tensile force. From these structural test, it has been reported that ultimate strength under the tensile force can be evaluated by design code in AIJ, but the evaluation method of deformation capacity remain unanswered. This paper presents the equilibrium condition of forces, compatibility condition and constitutive equation in the column base, and shows the method of carrying out the elasto-plastic analysis. The analytical results are in accordance with the test results well.
