SEISMIC FRAGILITY FUNCTION FOR SINGLE STOREY MASONRY WALL RC BUILDING IN PADANG CITY, INDONESIA

Abstract

Historical earthquakes in Indonesia show that low storey Reinforced Concrete with masonry wall buildings is vulnerable under seismic load. However, an adequate fragility function is suggested as a potential seismic assessment tool for RC buildings based on the actual condition of the existing structures. Therefore, this study aims to develop the fragility function for a typical low-storey RC building with a masonry wall in Padang City, Indonesia, based on the actual condition of the existing structures. The development of the fragility function used an analytical technique by incorporating the Applied Element Method (AEM) and Incremental Dynamic Analysis (IDA). AEM enables high accuracy of damage observation to the no-damage structures till the collapse stage. The damage stages at every PGA increment were compiled to obtain the cumulative probability. The log-normal distribution was used to derive the fragility function and create a curve. The developed fragility curve showed that at 0.3g PGA, the damage ratio of buildings sustained by slight, moderate, heavy dilapidation were 0.24, 0.54, and 0.92, respectively. The obtained fragility function to the damage ratio was validated based on the actual damage record from the 2009 West Sumatra Earthquake (2009 WSE). The comparison showed that the damage ratio obtained from the developed fragility function is close to the actual dilapidation from the 2009 West Sumatra Earthquake. Hence, the developed fragility function is potentially used as an assessment tool to predict the damage due to the Mega-Earthquake incident.