Seismic Performance of Structures with Vertical Geometric Irregularity Designed Using Partial Capacity Design

This Partial Capacity Design (PCD) offers new alternative in seismic design of structures. PCD allows some columns to be elastic during severe earthquake while the other columns and beams are allowed to be plastic. In order to keep the selected columns to be elastic, they are designed based on the ultimate load multiplied by a Magnification Factor (MF). Several researches show that the method is applied well especially on the medium-rise buildings (under 10-story) which are designed as special moment resisting frame in Indonesia. The plastic hinges occur at the expected member and structures having safe collapse mechanism. Continuing the prospective results, PCD needs to be observed on irregular structures. Therefore this research is aimed to evaluate the structural performance of 6- and 10-story buildings with vertical irregularity (vertical set-back). The limitation of natural fundamental period as stated in SNI 03-1726-2002 clause 5.6 is not considered to avoid the use of minimum reinforcement in the design. The structural performance is evaluated using static nonlinear pushover and dynamic nonlinear time history analysis. Results show that PCD fail to meet the expected failure mechanism due to improper use of Magnification Factor and incorrect selection of column dimension at the vertical set-back region.