The generation of earthquake damage probability curves for recovery time of school buildings in Taiwan

In this study, 247 school buildings whose derived site ground motion was larger than seismic intensity 5+ from the Chiahsien, Hualien, Taitung, and Hengchun earthquakes were surveyed. In addition, 138 school buildings from the 1999 Chi-Chi earthquake whose derived site ground motion was larger than seismic intensity 5+ were also investigated. After classifying the recovery time of each school building into slight, moderate, and extensive levels, the probability ratios of recovery time were computed by using the log-normal distribution method, survival analysis and nonlinear regression. λ and η are estimated by the process of non-linear regression. Finally, probability curves for school buildings grouped in three categories, "small-intensity", "large-intensity", and "all-intensity" based on collected earthquake recovery data sources, are developed. The log-normal distribution curve fitting algorithm was used to plot their corresponding recovery time probability curves. In addition, four probability curves of recovery time events for the school buildings were provided in this study such as "Earthquake to Start construction (ES)", "Start to Finish construction (SF)", "Finish construction to Use (FU)", "Earthquake to Use (EU)". This study concludes that the stage of "From earthquake to start construction (ES)" influenced the recovery time needed most. Hence, an appropriate administrative procedure can definitely shorten school reconstruction periods, and the probability curves of recovery time can be useful for planning school reconstruction after an earthquake.