A STUDY ON THE RELATIONSHIP BETWEEN GEOTECHNICAL, MINERALOGICAL AND CHEMICAL PROPERTIES OF PLIOCENE CLAY SOILS IN ESKISEHIR

Both geotechnical and mineralogical characteristics of the sixty five disturbed Pliocene core samples taken from Eskisehir province were examined in detail. In order to evaluate the mineralogical properties of soil samples, X-ray, differential thermal analysis-thermal gravimetric (DTA-TG), infrared spectroscopic (IR) and scanning electron microscopy (SEM) analyzes were performed. In the soil samples, the predominant clay mineral is smectite and a small amount of chlorite and illite are also observed based on the ideal DTA-TG and IR peaks and SEM analysis. The percentage of smectite, chlorite and illite positive correlated with liquid limit (LL), plastic limit (PL), plasticity index (PI) and clay activity (A). As the chemical composition of major oxides and geotechnical properties was evaluated together, it was determined that LL, PL and PI values with SiO2 and Al2O3 content have a positive relationship and also the increase of Fe2O3, Na2O and K2O amounts result in increasing LL and clay's activity in Esksehir soils. As a result of the study, it was evaluated that CaO content can be used as an alternative to A value in the evaluation of swelling potential.