Assessment of the effect of mineralogy on the geotechnical parameters of clayey soils: A case study for the Orta County, Çankırı, Turkey

• Published in: Applied clay science Vol. 164; pp. 44 - 53
• Main Authors: Akgün, Haluk, Günal Türkmenoğlu, Asuman, Arslan Kelam, Arzu, Yousefi-Bavil, Karim, Öner, Gökalp, Koçkar, Mustafa Kerem
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2018
• Subjects: Clay mineralogy; Geotechnical characteristics of clays; Orta County; Regression analysis; Turkey; Çankırı; Orta County; Çankırı; Turkey; Regression analysis; Clay mineralogy; Geotechnical characteristics of clays
• ISSN: 0169-1317; 1872-9053
• DOI: 10.1016/j.clay.2017.08.029

The purpose of this study is to investigate and relate the geotechnical parameters with the mineralogical properties of the Miocene and Plio-Quaternary (Pliocene to Quaternary) lacustrine and fluvial sediments, particularly clayey soils in the Orta County, Çankırı. The study area is located about 110km northeast of Ankara which is the capital city of the Republic of Turkey and Orta is a small county of Çankırı. The study area is a structural depression in the northern part of the Orta plain which is filled by fault-controlled continental sedimentation. In order to correlate the geotechnical and mineralogical characteristics and to establish a relation between these properties, comprehensive geotechnical laboratory studies have been performed. For correlation purposes, disturbed and undisturbed soil samples were collected from twenty-two locations of the study area. On these samples, mineralogical (i.e., methylene blue absorption, specific surface area determination, X-ray powder diffraction (XRD) and scanning electron microscope (SEM-EDAX)) analysis and geotechnical (i.e., sieve analysis, hydrometer, Atterberg (consistency) limits, oedometer and swelling) tests were implemented. By the aid of the statistical analysis, cross-correlation of the soil properties was established by the regression analyses performed. In particular, the plasticity index was correlated with cation exchange capacity, specific surface area, clay content, percent of fines, smectite and smectite/kaolinite ratio (SKR). There was a direct relationship between PI and smectite percentage as well as between PI and SKR. Additionally, the liquid limit was correlated with the clay content and the effect of the specific surface area on the swelling characteristics was studied. The effects of the mineralogical properties of the Orta clays together with the geological history on geotechnical parameters were investigated by considering the relationships mentioned. The results of the study revealed that the mineralogical characteristics had a significant effect on the geotechnical behavior of clayey soils of the Orta County which was demonstrated by regression analyses. Finally it was identified that the geotechnical properties of clayey soils can be approximated and more reliably determined if the mineralogical character and composition of clay is accurately investigated and well developed. •This study investigates the evaluation of clay mineralogy with its geological history and its origin.•It investigates the geotechnical and mineralogical characteristics of Orta Clay.•It investigates the correlation of the geotechnical and mineralogical features by regression analysis.•It investigates the assessment of the geotechnical and mineralogical features by regression analysis.•It investigates the effect of mineralogical characteristics of clay on engineering behavior of soil.