GIS (geographical information system) based investigation of liquefaction potential of Saray (Van) waste water treatment plant area

In this study, within the scope of the Final Project of Saray (Van) Waste Water Treatment Plant, Liquefaction Potential Index values were assessed under the coordination of Iller Bank General Directorate and Van Regional Directorate by using Geological Information Systems (GIS) for geological and geotechnical studies. The aim of this study is to investigate the liquefaction potential of the soils in the area where the Waste Water Treatment Plant planned to be constructed in Saray district of Van province. For this purpose, firstly, the mechanism of liquefaction, factors controlling the liquefaction of soils, soil deformations caused by liquefaction and evaluation of liquefaction potential were investigated. By considering all these issues, in this study, analyses were performed based on available geotechnical data from the boreholes which are carried out under the coordination of Iller Bank General Directorate and Iller Bank Van Regional Directorate. According to the laboratory results, soil size distributions in the study area were specified and soils were classified according to Atterberg limits and Unified Soil Classification system. Geotechnical data from the boreholes which are carried out under the coordination of Iller Bank General Directorate and Iller Bank Van Regional Directorate were used to prepare a map based on liquefaction potential. The peak ground acceleration value was calculated by taking into consideration the lengths of the active faults that will effect area of investigation and their distances to the investigation area. Within this scope, the data collected from earthquake investigations were categorized based on selected criteria and then liquefaction potential map of the waste water area based on this analysis results and calculated liquefaction severity index was established. The liquefaction potential of the study area was evaluated by using the potential earthquake scenario of magnitude Mw = 7 and the peak ground acceleration value of 0.300g, 0.360g and 0.400g, which may effect the waste water area. Liqueafaction analyses were carried out by using these values to produce liquefaction potential maps of the selected area where the liquefaction potential has been evaluated as low, medium and high.