Development of fragility curves for seismic vulnerability assessment: The case of Philippine GeneralĀ 

Michael B. Baylon, Maria Emilia P. Sevilla, Miller DL. Cutora, Rikki Mae S. Villa, Princess Mherlene P. Reynes, Jhona May V. Montemayor
Corresponding email: [email protected]


The Philippine General Hospital (PGH) is a tertiary hospital in Ermita, Manila, that was founded on August 17, 1907. It adheres to the philosophy of providing all Filipinos with internationally competitive, cost-effective, compassionate, and accessible health care. It was recently one of the COVID-19 facilities. The PGH sits 9.2 kilometers east of the West Valley Fault, making it more vulnerable to ‘The Big One,’ a 7.2 magnitude earthquake. Until present, no research has been done to examine the PGH’s seismic susceptibility in the case of a large-magnitude earthquake. In keeping with this, the study intended to analyze the seismic susceptibility of the Spine Building, one of PGH’s oldest structures. It focused on constructing fragility curves to assess if the building could sustain a 0.4g peak ground acceleration (PGA) earthquake with a maximum likelihood of exceedance of 10%, as required by the Philippine National Structural Code (NSCP) for Seismic Zone 4 sites. The study employed 12 worldwide and 12 local earthquakes from the Incorporated Research Institutions for Seismology, with PGA excitation levels ranging from 0.1g to 3.0g (with a 0.1g gap) (IRIS). The structural model of the PGH Spine Building was created using SAP2000, which was subsequently utilized to perform Pushover Analysis using the Capacity Spectrum Method (CSM). The PGH Spine Building might collapse with 0.538g PGA, which corresponds to Intensity VIII, according to the results of the developed fragility curves, producing significant structural shaking. Furthermore, for 0.4g PGA, the calculated highest likelihood of exceedance in the ‘collapse damage’ condition was 5.24 percent, with no results above 10%, implying that the PGH Spine Building complies with the NSCP seismic requirement for structures located in Seismic Zone 4. As a result, an adequate retrofitting strategy is not required for the PGH Spine Building.

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Seismic vulnerability assessment of Sta. Lucia high school in Pasig City Philippines using rapid visual assessment and fragility curves

Michael B. Baylon, Crispin S. Lictaoa, Independence Jcan C. Castillo, Chariz Kate P. Dungog, Leny Rose Jerusalem
Polytechnic University of the Philippines
Adamson University, Philippines
Corresponding Email: [email protected]

The Philippines being part of the pacific ring of fire, faces huge threats of massive damage to infrastructures after extensive earthquakes. One of the most vulnerable infrastructures is public school buildings, which are considered significant structures since they have both emergency and educational function value to the society. Sta. Lucia High School in Pasig, located near the West Valley Fault, will be the focus of this paper. The main objectives of this research are to implement rapid visual assessment using Safer Communities through Safer Schools (SCOSSO) application and to generate the seismic fragility curve of the building based on the Capacity-Spectrum Method. The researchers conducted a rapid but thorough assessment of the BCE II building by following the guidelines of the SCOSSO application. The building had an estimated seismic vulnerability of 66%, thus needing further comprehensive assessment. For the generation of fragility curves, the structural plan of the building was modeled in SAP2000 and subjected to 20 ground motion data. The results from the capacity spectrum method were then used for the seismic fragility curves. The structure was found to attain its completely damaged state at a PGA of 0.352g or greater, with a probability exceedance of 10% which takes place at the weaker axis of the building in the north-south direction of the earthquake along the x-axis. The fragility curves have shown that the stronger the peak ground acceleration, the higher the chance of the building to collapse.

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