Rapid and in-depth analysis for seismic risk evaluation

The high public demand on housing in urban areas requires the government of Indonesia to adopt a policy of encouraging the development of vertical housing. Cilacap has been allocated Rusunawa (low-income apartment) development in 2006. Evident from some earthquakes occurrence in recent years, however, Cilacap may be seen as an earthquake prone region which posing some risk to this type of vertical structures. The Appropriate strategy should be performed to evaluate the seismic risks of this local government owned four stories low-income apartment. This paper demonstrates two tier evaluation strategy; rapid evaluation and in-depth analysis and compares both results. First evaluation was conducted by means of Building Rapid Visual Screening (RVS) of FEMA 154 of the Rusunawa block A and B. The result was used further to calculate seismic risk score (SR) which exhibit the probability of the building damage given the Maximum Considered Earthquake (MCER) that will occur during the Rusunawa service life. The in-depth analysis was conducted by developing fragility function expressed in the form of fragility curves for the Rusunawa. The fragility shows the probability that certain damage states will be exceeded given the intensity of earthquakes which will occur during building service life. The fragility was developed as lognormal curves in which the building response to earthquake input was analyzed by means of pushover.