Analysis of road embankments under earthquake effects

In this thesis study, the roads within the network of the General Directorate of Highways that were damaged following two earthquakes—occurring approximately 9 hours apart and centered within the provincial borders of Kahramanmaraş on February 6, 2023—were identified among the provincial, state, and motorway roads located in the disaster zone. The post-earthquake actions taken by the institution regarding these damaged roads were examined in detail. In addition, to analyze road embankments under the effect of earthquakes, a road embankment that sustained damage during the earthquakes was studied. For this purpose, a literature review was conducted, and the 53.5 km long Şanlıurfa-Hilvan Junction Bozova–8th Regional Border road, part of the road network under the jurisdiction of the 9th Regional Directorate (Diyarbakır) of the General Directorate of Highways, was analyzed. Following the earthquakes, the retaining walls composed of five anodes located within the 100-meter section between Km: 50+970 - 51+070 of the road collapsed, and severe damage occurred in the embankment on the left side of the road. These damages were evaluated as a case study within the scope of this thesis. In this context, the geological and geotechnical reports as well as the soil surveys conducted before the earthquakes for the Şanlıurfa-Hilvan Junction Bozova–8th Regional Border road were examined. Moreover, the damage that occurred after the earthquakes was observed through field investigations. As a result of these studies, the soil parameters to be used in the analyses were determined. For data that could not be directly identified but were necessary for the analysis, values used in previous literature studies related to the investigation area were utilized. To analyze the road embankments under seismic effects, the finite element method-based software PLAXIS 2D was used. Based on the earthquake and non-earthquake analyses conducted on the road embankment, it was determined that the obtained displacement and stress distributions were consistent with field observations, and relevant recommendations on the subject were presented.