VULNERABILITY ASSESSMENT OF NON ENGINEERED HOUSES BASED ON DAMAGE DATA OF THE 2009 PADANG EARTHQUAKE IN PADANG CITY, INDONESIA

Several powerful earthquakes have struck Padang during recent years, one of the largest earthquake event was an M 7.6 that occurred on September 30, 2009 and caused more than 1000 casualties. Following the event, A 12-site microtremor array investigation to gain a representative determination of the soil condition of subsurface structures in Padang has been conducted. From the dispersion curve from the array observations, the central business district of Padang corresponds to relatively soft soil condition with Vs30 less than 400 m/s. Because only one accelerometer was existing, the 2009 Padang earthquake was simulated to obtain peak ground acceleration for all sites in Padang city. By considering the damaging data of the 2009 Padang earthquake for engineered houses, Seismic risk vulnerability estimation of non-engineered houses for rock, medium and soft soil condition can be obtained, and also estimate the loss ratio based on the ground response, seismic hazard of Padang and the existing damaged to non-engineered structure houses due to Padang earthquake in 2009 data for 500 return periods of earthquake events.