GIS-based Building Damage Assessment due to A Scenario Earthquake in Metro Manila, Philippines Saburoh MIDORIKAWA 1 / smidorik@enveng.titech.ac.jp Kazuo FUJIMOTO 1 / kazu@enveng.titech.ac.jp Hiroaki YAMANAKA 1 / yamanaka@depe.titech.ac.jp Hiroyuki MIURA 1 / hmiura@enveng.titech.ac.jp Benito M. PACHECO 2 / bmpacheco@vibrametrics.net Bartolome C. BAUTISTA 3 / bart@phivolcs.dost.gov.ph 1) Tokyo Institute of Technology, Japan 2) Vibrametrics, Inc., Philippines 3) Philippine Institute of Volcanology and Seismology, Philippines Abstract This paper presents the procedure for GIS-based building damage assessment which is applicable to mega cities in the Asia-Pacific region. The procedure consists of ground motion estimation using the hybrid simulation technique, building response estimation using the capacity spectrum method, and damage distribution estimation using the GIS building inventory data. The procedure is applied to Metro Manila, Philippines. The results should be useful for the stakeholders such as administrators and structural engineers, in order to plan disaster mitigation strategies. Key Words: damage assessment, building, vulnerability, seismic risk, Metro Manila 1. Background and Objectives Concentration of population to urban areas is a common problem in developing countries including the Asia-Pacific region. The number of mega-cities, which are vulnerable to disasters, is increasing. The disaster mitigation activities in mega-cities should be strengthen immediately. In order for efficient earthquake disaster mitigation planning, the earthquake loss estimation is indispensable. It is, however, common that the data necessary for the loss estimation is not fully available in developing countries. As a result, it is difficult to practice the reliable loss estimation such as the GIS-based damage assessment. In this paper, we propose a simplified procedure for the GIS-based damage assessment which is applicable to the Asia-Pacific region. The procedure consists of ground motion estimation using the hybrid simulation technique, building response estimation using the capacity spectrum method, and damage distribution estimation using the GIS building inventory data. The procedure is applied to Metro Manila, the capital of Philippines, where the influx of population and the urban sprawl have been strongly observed. The results will be provided to the stakeholders as a part of the Metro Manila case study. 2. Methodology In order to provide basic information for disaster planning, the building damage due to a scenario earthquake is assessed. The flow of the damage assessment is shown in Fig. 1. The ground motion at engineering bedrock is computed by the hybrid simulation method. Then, the ground motion at surface is computed by the equivalent-linear soil response analysis using the soil profile model at each site. 1