Method of judging collapse of SRC and RC columns failed by shear and axial force

Middle stories in many SRC and RC buildings collapsed in 1995 Kobe Earthquake. Judging from the complete crash of the collapsed story, the buildings are supposed to have collapsed because it could not sustain the stationary load. Axial force P cr of the shear collapse for steel reinforced concrete (SRC) columns and reinforced concrete (RC) columns were derived by applying the principle of virtual Work under the assumed shear failure mechanism. A method of judging the collapse caused by shear and axial force is proposed. Experiments of SRC and RC beam-columns were performed to verify the validity of the proposed method. P cr of RC beam-columns in 6th story real collapsed buildings were also calculated and its collapse was judged.