Earthquake simulation tests on a 1:15 scale 25-story RC flat-plate core-wall building model

To verify the seismic performance of high-rise reinforced concrete flat-plate core-wall building structures designed as per the recent seismic code KBC 2009 or IBC 2006, the earthquake simulation tests were conducted on a 1:15 scale 25-story building model. The following conclusions are drawn from the test results: (1) The vertical distribution of acceleration during the table excitations revealed the effect of the higher modes, whereas the free vibration after the termination of table excitations was governed by the first mode. The maximum values of base shear and roof drift during the free vibration can be either similar to, or sometimes larger than the values of the maximum responses during the table excitation. (2) With the maximum roof drift ratio of 0.7% under the maximum considered earthquake in Korea, the lateral stiffness degraded to approximately 50% of the initial stiffness. (3) The modes of cracks appear to be a combination of flexure and shear, in the slab around the peripheral columns, and in the coupling beam. The energy dissipation through the inelastic deformation was dominant during the free vibration after the termination of table excitation rather than during table excitation. Finally, (4) the walls with special boundary elements at the first story did not reveal any significant inelastic behavior, with the maximum curvature being only 21% of the ultimate curvature corresponding to the ultimate concrete compressive strain of 0.00638 m/m intended in the displacement-based design approach.