Effects of fly ash and desulphogypsum on the strength and permeability properties of Çayırhan soil

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Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, İnşaat Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2005

Öğrenci: MURAT ŞAHİN

Danışman: ERDAL ÇOKÇA

Özet:

Çayırhan soil is a collapsible soil. Collapsible soils are generally unsaturated, low-density soils with high voids between grains where the binding agents are sensitive to saturation. When exposed to water, binding agents break, soften or dissolve such that the soil grains shear against each other and reorient in denser configurations. This reconfiguration causes a net decrease in the soil mass, resulting in large and often unexpected settlements, which can totally destroy roads, underground utilities, and structures and alter surface drainage. Uses of collapsible soils as a natural construction material in fills or embankments also may cause serious stability problems. In this study, an extensive research program was carried out to investigate some geotechnical properties such as compaction, triaxial strength, bearing ratio and permeability of collapsible soil, found in Çayırhan Thermal Power Plant area, by treating with Class C fly ash and desulphogypsum (thermal power plant by-products that are to be handled for environmental reasons) in various proportions. The study has revealed that 20% and 25% fly ash or 5% desulphogypsum treatments (by dry weight of the mixture) improve the strength and bearing characteristics of Çayırhan soil.