Estimation of liquefaction potential using geostatistics in Eskisehir

Abstract

The scope of this study is to estimate liquefaction risk of locations that have no data, according to the 64 bore-hole locations, those Standard Penetration Test (SPT) values known and factors of safety against liquefaction are calculated. The scenario is depending on 0.4g ground acceleration may be occurred by an earthquake, which magnitude is 6.4 on Richter Scale, impact Eskisehir City Center. Ordinary Kriging is chosen as an estimation method, which is a well known methodology of geostatistics, in this study. GIS (Geographic Information System) tools are also used for mapping, analyzing the spatial distributions of the data, and overlaying different layers of the studied region such as lithology, elevation, building blocks, district boundaries, etc. Classification of factors of liquefaction values, which are estimated according to the scenario, is made by GIS tools as risky, potential, and no risk, respectively. Due to the liquefaction potential prediction map, conglomerate and alluvial regions beside the Porsuk River, which passes through the city center, are liquefiable zones. Hilly regions in the south, laid on schist lithology, are non-liquefied, and the contact zones between these lithologies, are estimated as moderate liquefiable zones, in respect of the scenario. Finally, the results are compared with the Eskisehir Preliminary Disaster Mitigation Plan.