Development of risk-targeted hazard maps for the city of Manila, Philippines for low-rise and mid-rise reinforced concrete buildings

• Main Author: Mallari, Royce Argel N.
• Format: text
• Language: English
• Published: Animo Repository 2022
• Subjects: Earthquake hazard analysis; Earthquake engineering; Civil Engineering
• Online Access: https://animorepository.dlsu.edu.ph/etdm_civ/24; https://animorepository.dlsu.edu.ph/cgi/viewcontent.cgi?article=1023&context=etdm_civ
• Institution: De La Salle University

The latest Seismic Hazard Map of the Philippines used for the design of buildings is described by the probability of occurrence of an earthquake and not by the probability of collapse of buildings when that earthquake occurs. Thus, this study created the risk-targeted seismic hazard maps that will provide information on ground motion with a 1% probability of building collapse in 50 years, focusing on the City of Manila. Probabilistic and Deterministic Seismic Hazard Assessments (PSHA and DSHA) were conducted to obtain the seismic hazard at the target site. While, building samples were generated and analyzed to define the generic fragility curve function that is described by a lognormal standard deviation, β. In this study, the β=0.7 was obtained using the generated building samples. An iterative procedure to obtain the probabilistic risk-targeted ground motion (RTGM) was conducted by utilizing the hazard curves from the PSHA and the generic fragility function. Due to the different suggested values for β in different publications, a sensitivity study was conducted to compare the probabilistic RTGM results when β=0.7 to the suggested value of ASCE 7-16 (β=0.6) and Luco et al. (2007) (β=0.8). Only a 5% difference was obtained with the comparison of probabilistic RTGM values in the sensitivity study. The results of the probabilistic RTGM were compared to the deterministic ground motion. The minimum of the two was considered as the risk-targeted maximum considered earthquake (MCER). The MCER values were plotted and mapped to develop the risk-targeted hazard maps. This procedure was done for soil types A to E based on NSCP 2015 soil profile classification. The created risk-targeted hazard maps for Manila can be used to obtain the design response spectrum to be used for the design of new buildings or assessment of existing structures in Manila. Keywords: MCE; MCER; PSHA; DSHA; Risk-Targeted; Seismic Hazard