Strength and stiffness on lab-mixed specimens of stabilized Norwegian clays

Abstract

In situ ground improvement by deep mixing the soil with stabilizing agents or binders as lime, cement, cement kiln dust or a combination of these is the most common method applied in the Nordic countries. In Norway, soil stabilization with deep mixing has been applied to soft to medium stiff clays with sensitivity ranging from about 5 to over 100. In this paper, a large database of laboratory results from lab-stabilized Norwegian clays is presented. The data show, for example, that shear strength of the stabilized clays decreases when the water to binder ratio (i.e. total clay water to binder content ratio) increases, and that the stiffness development is mainly controlled by time. Some observations from more advanced laboratory testing on samples taken from stabilized columns in the field highlight the anisotropic behaviour of the stabilized clays and the increase in strength with in situ stresses. The data presented is a useful guide on the selection of binder mixes for specific project applications and it should always be supplemented by testing on site-specific lab-mixed specimens.