Performance of Direct Displacement Based Design on Regular Concrete Building Against Indonesian Response Spectrum

The renewal of Indonesian seismic code from SNI 1726-2002 into SNI 1726-2012 brings significant change in the design spectrum. Focused on several regular plan concrete building which have been design using displacement based design method, the aim of this study is to verify their performance using nonlinear time history analysis based on parameters: drift, damage indices, and plastic mechanism determined by FEMA 356. The excitation is spectrum consistent accelerogram based on El-Centro 1940 N-S, to match with the new Indonesian response spectrum for soft soil in low- and high intensity area. It is found that the code-designed buildings are not suitable for the targeted design of level-2 with maximum drift of 2.5% due to major. This is caused by improper selection of SNI spectrum as the design major earthquake. In fact, it is only equivalent to small earthquake. Although buildings survive up to a very rare earthquake without collapse but they suffer excessive damage and rotation due to small- to major-earthquake. The capacity design procedure is able to maintain ductile mechanism, but some columns experience yielding at prohibited locations