This study is aim at evaluating ultimate seismic capacity of a steel moment-resisting frame by conducting scale model tests, whose performance is improved by two structural systems. One is a proposed pinned column support system, which prevents the first story's columns from yielding, and the other is a leaning column, which controls a deformation pattern of a main frame. Furthermore, the virtual work method is applied to predict collapse mechanisms, considering the effect of beam-column flexural stiffness distribution and increase in flexural strength due to strain hardening. The method successfully predicts collapse mechanism of frames with some modification, estimated by static analysis and scaled model tests.
