Asia Conference on Earthquake Engineering 2004 – Manila, Philippines Association of Structural Engineers of the Philippines (ASEP) GIS-BASED EARTHQUAKE DAMAGE ASSESSMENT CONSIDERING SEISMIC CAPACITY OF EXISTING BULIDINGS IN METRO MANILA, PHILIPPINES Saburoh Midorikawa, Kazuo Fujimoto, Hiroaki Yamanaka, Hiroyuki Miura, Benito M. Pacheco, and Bartolome C. Bautista ABSTRACT : The building damage due to a scenario earthquake in Metro Manila, Philippines is assessed in order to provide basic information for disaster planning and risk management. The West Valley Fault is selected as the source of the scenario earthquake. Using the fault parameters of the earthquake together with the three-dimensional deep underground model, the ground motion on engineering bedrock is computed by the hybrid simulation method. The surface ground motion is computed by the equivalent linear soil response analysis by employing the surface soil profile model. The building response is evaluated by the capacity spectrum method. The existing buildings in Metro Manila are classified into several categories in terms of the structural types, the number of stories, and the design vintages. By integrating the expert opinions of experienced structural engineers, the capacity curve for each category is developed. The nonlinear building response is estimated from the capacity curve and the site-dependent response spectrum of the ground motion. Combining the GIS building inventory data updated by the high-resolution satellite image data and the damage state of each building category estimated from the fragility curve, the building damage throughout Metro Manila is computed. KEYWORDS: Building Damage Assessment; GIS; Seismic Capacity; High-Resolution Satellite Image; Metro Manila 1. INTRODUCTION Influx of population to urban areas is a common problem faced by developing countries in Asia-Pacific region. The number of mega-cities, which are vulnerable to disasters, is increasing. The disaster mitigation activities in mega-cities should be strengthening immediately. The earthquake loss estimation is indispensable to efficient earthquake disaster mitigation planning. 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 Metro Manila, the capital of Philippines, the population concentration and the urban sprawl have been strongly observed. In this paper, as an example of the GIS-based damage assessment by means of a simplified procedure, which is easily applicable to the Asia-Pacific region, we conduct the building damage assessment in Metro Manila.