Shaking Table Tests of a High-Rise RC Bearing-Wall Structure with Bottom Piloti Stories

The severe shortage of available sites in highly developed metropolitan areas in Korea necessitates the construction of high-rise buildings which meet the needs of residence and commercial activity simultaneously. These buildings are constructed, in general, using the bearing-wall system for the upper apartments and the frame system for the lower commercial space. The objective of this study is to investigate the seismic performance of this type of building structure. For this purpose, a 1:12 scale 17-story reinforced concrete model structure was constructed according to the similitude law, in which the upper 15 stories have a bearing-wall system while the lower 2 stories consist of a moment-resisting frame system. This model was then subjected to a series of excitations which simulated the Taft N21E accelerogram, whose peak ground acceleration (PGA) was modified to be 0.11g, 0.22g, 0.3g, 0.4g, 0.6g, and 0.8g, respectively. Test results show that the piloti stories experience the shear and overturning deformation simultaneously and that the axial force in the column due to overturning moment can be reasonably predicted by using the UBC-97 load combination while the shear resistance of the column can vary dramatically with variations of the axial forces.