抄録
A model is presented for pushover analysis of reinforced concrete soft-first-story frames with columns extended toward inside of frames. The model includes a rotational spring of first-story column and that of beam. The beam spring represents the flexural resistance of the section which includes the beam and the second-story column. The yield deformation of each spring is determined based on the observed strain distribution of the longitudinal bars. The proposed model agreed with the test results much better than the conventional model, which provided up to twice of the observed strength and a half of the observed yield deformation.