In-situ and numerical assessments to evaluate site effects in Orta-Çankırı province by comparative geophysical and geotechnical investigations


Thesis Type: Doctorate

Institution Of The Thesis: Middle East Technical University, Faculty of Engineering, Department of Geological Engineering, Turkey

Approval Date: 2016

Thesis Language: English

Student: Arif Mert Eker

Supervisor: HALUK AKGÜN

Abstract:

Local site conditions of Orta district in Çankırı were deduced from in-situ measurements of dynamic and geotechnical properties of the soils in the context of evaluation of the site effects under a possible earthquake. The study area is under the control of active faults in the form of a strike slip basin and is almost entirely located within this basin. Plio-Quaternary and especially Quaternary alluvial sediment conditions were determined through the development of a geo-engineering database for the study area. The database was constructed by the results obtained by destructive geotechnical and non-destructive geophysical field methods along with geotechnical laboratory tests. In order to identify the dynamic soil behavior within the Orta pull apart basin under a possible ground motion, 1D and 2D numerical analyses utilizing equivalent linear approach were performed. Additionally, an experimental site effect study was carried out by using a single mobile velocimeter in the study area. The results of the microtremor method and the numerical analyses were compared with each other and the performances of the utilized methods were evaluated to determine the site effects at the study area. As a result, the seismic responses of the young and soft sedimentary units within the Orta pull apart basin have been proposed.