Seismic response characteristics of high-rise RC wall buildings having different irregularities in lower stories

Three 1:12 scale 17-story RC wall building models having different types of irregularity at the bottom two stories were subjected to the same series of simulated earthquake excitations to observe their seismic response characteristics. The first model has a symmetrical moment-resisting frame (Model 1), the second has an infilled shear wall in the central frame (Model 2), and the third has an infilled shear wall in only one of the exterior frames (Model 3) at the bottom two stories. Based on the test results, which are analyzed and compared, the following conclusions are drawn. The estimated fundamental periods for other structures than moment frames and bearing wall structures in UBC 97 and AIK 2000 appear to be reasonable. The total amounts of energy absorption by damage are similar regardless of the existence and location of the infilled shear wall. The largest energy absorption is due to overturning, followed by that due to shear deformation. The rigid upper system renders rocking behavior in the lower frame, and thereby, the self weight contributes up to about 23% of the resistance against the total overturning moment.