Investigation of tensile strength and deformation characteristics of Varamin collapsible soils at undisturbed, reconstituted and treated states

Tensile failures including tensile cracks on the upper part of instable slopes, earth fissures, tensile cracks in earth dams, and any kind of tensile failures resulted from tensile stresses within soil body are considered as important engineering geological features. Studying tensile strength and deformation characteristics of soils can have a great role in the prevention of adverse phenomena resulted from tensile failures in soils. The Varamin collapsible soils are subjected to tensile fractures and earth fissuring because of the tensile stresses raised from the land subsidence of the Varamin plain. Therefore, in this study, the strength and deformation characteristics of these soils were investigated at undisturbed, reconstituted and treated states. Results indicate that, when undisturbed collapsible soils are subjected to tensile stresses, they show a low tensile strength and behave brittle in tension. Reconstituted soils have a lower tensile strength in comparison with undisturbed soils and behave very soft and fail easily in tension. Treated soils have a higher tensile strength in comparison with undisturbed soils and behave more ductile in tension and tolerate more deformation before tensile failure. Results indicate that the treatment of the collapsible soils with stabilizer materials together with compaction is an efficient method for strengthening these soils against tensile stresses and for improving their performance in tension.