Abstract

The Seyrek highway intersection bridge on the İzmir-Menemen-Aliağa Highway is the study site of this research and is located in the Menemen town of İzmir city in Turkey. It has been determined that deformations have occurred in the bridge piers and approach embankment at the Seyrek highway intersection bridge on the İzmir-Menemen-Aliağa Highway. There is an active stream starting from 830m southwest of the study area and passing 2km northwest of the study area and the groundwater level determined according to the borehole data is between 3.1 and 4.05m. The liquefaction potential of the study area was calculated using the “Simplified Method” approach in this study. The liquefaction potential of the project area was found to be between 3.80m and 10.5m in depth using laboratory and field tests. Moreover, no liquefaction potential was found after 10.5 meters despite the soil type being SM-SC with low SPT-N values. Therefore, the importance of the effects of grain properties such as the percentage of plastic fines, average grain diameter and plasticity index in liquefaction analysis based on the SPT-N number was also shown in this study. According to the settlement analyses, the time required for the total settlement to decrease to the allowable levels has been calculated as approximately 49.33 years and since the filling has been present for more than 7.5 years, the remaining settlement is above the allowable specification criteria. As a result, soil improvement and reinforcement methods such as DSM columns and drainage canals were advised to be used in Seyrek highway intersection bridge embankments in the study field to ensure the safety of the engineering projects against the damage caused by liquefaction and settlement in the study area.

Keywords:Liquefaction potential; Simplified method; Earthquake and liquefaction