Shake-Table Tests of a Concrete Frame Sustaining Column Axial Failures

Earthquake simulation tests of a one-third-scale, three-story, three-bay, planar reinforced concrete frame were conducted to gain insight into the dynamic collapse of older-type construction. Collapse of the frame was the result of shear and axial failures of columns with widely spaced transverse reinforcement. The frame geometry enabled observation of the complex interactions among the failing columns and the surrounding frame. The tests showed that the failure type and rate depended, on the axial load level, stiffness of the surrounding framing, and intensity and duration of shaking. Key factors affecting the initiation and propagation of shear and axial failures are discussed.