Full-scale test of composite frame subjected to long-period ground motions-e-defense shaking table test

A series of full-scale shaking table tests on a substructure specimen representing lower stories of a 21-story steel building are conducted. The specimen is designed as a four-story, two-span by one-bay full-scale steel moment frame structure topped with an equivalent mass and rubber system. A series of long-period, long-duration ground motions are applied to the specimen successively, and the maximum inter-story drift angles are found to be smaller than 0.5% and 1.0% under medium and large ground motion levels. Composite beams exhibit an increase in the strength on the order of 10 to 35% over the corresponding bare beams, and fractures are developed in the bottom flanges after serious cyclic loading. Shop-weld connections show better cumulative deformation capacities than field-weld connections. Hysteretic behavior remained relatively stable, with no severe strength deterioration observed even after the connections fractured.