16 th World Conference on Earthquake, 16WCEE 2017 Santiago Chile, January 9th to 13th 2017 Paper No 659 Registration Code: S-Y1463240354 Sensitivity Analysis on Seismic Risk-Coefficients for Input to Indonesian Earthquake Resistance Building Code I Wayan Sengara (1) , Indra D. Sidi (1) , Widiadnyana Merati (2) , and Andri Mulia (3) (1) Associate Professor, Faculty of Civil and Environment Engineering, Institut Teknologi Bandung (ITB), Indonesia iws@geotech.pauir.itb.ac.id and wayansengara@yahoo.com; indradjati@gmail.com (2) Professor, Faculty of Civil and Environment Engineering-ITB, Indonesia widimerati@gmail.com (3) Research Assistant, Faculty of Civil and Environment Engineering-ITB, Indonesia andri.mulia@comlabs.itb.ac.id Abstract New development in seismic design criteria of buildings is by adopting risk-targeted ground motions (RTGM)-based instead of previously adopted uniform hazard-based criteria. The RTGM adopts 1% probability of building collapse in 50 years, introducing a risk-coefficient. Risk-coefficient is defined as ratio of RTGM and maximum considered earthquake (MCE) hazard adopting 2% probability of exceedance in 50 years. The RTGM integrates hazard curve and building fragility, with a logarithmic standard deviation, β, value. This paper presents sensitivity analysis on hazard curves and β-values of six (6) specific sites in Indonesia. The hazard curves are represented by various seismic source conditions representing both subduction and shallow crystal zones with various level of intensities. This is obtained from recent probabilistic seismic hazard analysis conducted for revision of Indonesian seismic hazard maps. β-values are varied representing variation of building qualities. The sensitivity analysis is conducted for two spectral accelerations at periods of 0.2-second (short) and 1- second period. The analysis shows that there is about 7-14% deviation in risk coefficient values resulted from 0.6-0.8 variation in β-value and about 18-34% deviation resulted from 0.6-1.0 variation in β-value. Use of β value of 0.7 in the current Indonesian code is considered to be acceptable. Keywords: Seismic; building code, spectral acceleration; ground-motion; fragility; risk-coefficient