New 2019 Risk-Targeted Ground Motions for Spectral Design Criteria in Indonesian Seismic Building Code

Abstract

Indonesia has followed development of new seismic design criteria in the new seismic building codes, from hazard-based in the former SNI-03-1726-2002 to the current risk-based SNI-1726-2012. The major changes in SNI-1726-2012 are using Risk-Targeted Maximum Considered Earthquake (MCER) Spectral Response Acceleration maps. Five years later (2017), the seismic hazard maps have been updated adopting the most recent data and current state of knowledge in probabilistic and deterministic seismic hazard assessment methodologies. To establish the New 2019 Risk Targeted Ground Motion (RTGM) of spectral acceleration (Ss and S1), and risk coefficients (CRS and CR1), for both short (T=0.2s) and 1-second (T=1s) periods, respectively have been developed based on the 2017 Indonesian hazard maps. The RTGM was calculated as the spectral value resulting in 1% probability of building collapse in 50 years through numerical integration of hazard curves and structural capacity. The log-normal standard deviation (?) of the structural capacity envelope has been revised from 0.70 to 0.65. This paper presents the new resulted RTGM maps. Furthermore, the paper also presents revision of seismic amplification factors for 0, 0.2, and 1 second periods (FPGA, Fa, and, Fv) to generate ground surface maximum and design spectra associated with the siteclassifications.

Field Insights and Analysis of the 2018 Mw 7.5 Palu, Indonesia Earthquake, Tsunami and Landslides

“…The updated seismic hazard map has led to new seismic design criteria in the most updated seismic building codes (Sengara et al, 2020). The results from our study will lead to a further improvement to the seismic hazards maps of Indonesia and can provide critical engineering parameters such as peak ground acceleration (PGA) or peak ground velocity (PGV) where limited instrumental ground motion recordings are available, such as in Palu.…”

Studi Komparasi Perhitungan Beban Gempa Statik Ekuivalen Menggunakan Software Sap 2000 Dengan Sni 1726 2019

“…Ada banyak international code yang disediakan oleh SAP 2000 untuk menghitung beban gempa, seperti Italian Code, Chinnes Code, Domminician Republic Code, Eurocode dan Minimum Design Loads and Associated Criteria for Buildings and Other Structures (ASCE/SEI 7-16), dll. Negara Indonesia saat ini telah menggunakan SNI 1726 2019 sebagai peraturan pembebanan gempa terbaru, yang isinya mengadopsi ASCE 7-16 [16] [17]. Dalam penentuan beban gempa statik ekuivalen dapat menggunakan ASCE 7-16 dengan menyesuaikan seismic coefficient dan parameter gempa.…”

Review and comparison of different strategies to define earthquake design accelerations

“…Risk‐targeted design was chosen as the basis for the current United States of America earthquake design code 9 and that of Indonesia 10 . In these cases, a single fragility curve has been used, assigning a large uncertainty to the true strength, aiming to make it representative for all types of buildings (i.e., structural configurations and materials), thus yielding a single design‐coefficient map.…”

“…Risk-targeted design was chosen as the basis for the current United States of America earthquake design code 9 and that of Indonesia. 10 In these cases, a single fragility curve has been used, assigning a large uncertainty to the true strength, aiming to make it representative for all types of buildings (i.e., structural configurations and materials), thus yielding a single design-coefficient map. Although practical from the coding perspective, the chosen fragility curve may be over-conservative for certain building types, yielding larger collapse probabilities than the real ones, thus moving the approach away from the initial target of uniform collapse probabilities.…”