Real time earthquake hazard map of liquefaction in Korea

The purpose of this study was to create a real-time liquefaction hazard map at national level by taking into consideration the differences between the site acceleration and intensity scale distribution depending on the occurrence site when an earthquake would take place. To this end, the two sub-studies were conducted. The first was to create a liquefaction hazard map for each site acceleration for an earthquake based on the evaluation method of macro-liquefaction for each site acceleration. The second was to establish a real-time liquefaction hazard map DB that could be linked with the system for earthquake disaster prevention by integrating the liquefaction hazard maps of all the site accelerations. First, this study conducted the liquefaction evaluation by developing the metropolitan area liquefaction evaluation program based on Excel in order to use approximately 14,040 metropolitan area site data. This study deducted the Liquefaction Potential Index (LPI) for each site depth by using the correction Seed & Idriss method and the site amplification coefficient satisfying South Korea’s earthquake-resistant criteria in relation to the liquefaction evaluation. This metropolitan area liquefaction evaluation program is able to skip the site response analysis for earthquake used when creating a facility-centric hazard map in order to create a liquefaction hazard map at city, provincial and national levels. Also, this metropolitan area liquefaction evaluation program is able to substitute it with a site amplification coefficient in order to reduce the duration of liquefaction evaluation. As a result, it was possible to reduce the time taken to create a liquefaction hazard map by approximately 50,000 hours. In the end, the liquefaction hazard map for each site acceleration was created based on the interval of 0.04g from 0.06g to 0.38g. In regard to the second sub-task that was to create a real-time liquefaction hazard map, the basemap that would become a basis of creating a liquefaction hazard map was designed to be linkable after using the cell unit of 2Km by 2Km used by the system for earthquake disaster prevention. Then, this study deducted the relational formula through the earthquake acceleration for each coordinate and the correlation with LPI. At this time, the optimal relational formula was applied in relation to LPI for each site acceleration and the correlation between the relational formulas among those two-variable 4 relational formulas. For the verification of this study, a real-time liquefaction hazard map of earthquake scale 6.0 was created in consideration of the difference in the site distribution for an earthquake as to Hongseong Earthquake and Odae-mountain Earthquake, which took place previously.