Evaluation of Liquefaction Potential of a Coastal Region in Atakum

Abstract

Liquefaction became a major seismic phenomena just after the earthquakes occurred in Alaska and Niigata in 1964. Soil liquefaction is one of the most important causes of damages induced by earthquakes. Liquefaction can be defined as temporary loss of strength of saturated, coheisonless soil deposits under transient and cyclic loading due to excess pore water pressure generation. Consequently, the most appropriate and typical soil condition which brings the potential out to liquefy is loose sand with a groundwater table close to ground surface. This study is concerned with determination of liquefaction potential in a coastal region in Atakum County of Samsun Province, Turkey. Therefore, empirical equations were used to determine the peak ground accelerations for three scenario earthquakes with the magnitudes of 6.5, 7.0 and 7.2 in order to consider in the Simplified Procedure context proposed by Seed and Idriss (1971). Liquefaction potential evaluations were performed using SPT blow counts for four boreholes for sandy portions of the soil profile which exist in the first 20 meters below ground surface. In addition to analytical evaluations, two dimensional nonlinear analyses were ran with Towhata-Iai constitutive model suitable for liquefaction analysis available in DIANA finite element software to clarify excess pore pressure generation that leads to liquefaction. Finally, all the results are presented and discussed as a conclusion.