Geotechnical Hazards Induced by Montmorillonite Presence

Abstract

Often referred to as expansive soils in international literature, soils with large swelling and shrinking potential, are defined as natural materials that exhibit volume variations related to variations of moisture. Most professionals consider that the expansive manifestations are related to the mineralogic composition, especially with the presence of the smectite class of minerals, more specifically with the montmorillonite. Despite sustained worldwide studies over decades, the direct and firm correlation between the number of clayey minerals and expansive properties has not reached a conclusive form, and the behavior of expansive soils remains still unrevealed and exhibits unexpected features under moistening or drying conditions in natural habit, or in relation with infrastructure works. This chapter presents the results of an extended and complex geotechnical investigation of expansive soils which concludes with the validation of a simple procedure of identification of the areas where the swelling behavior of soils may exceed the equilibrium of the geological structure and produce a variety of effects such as lumps or landslides in areas with sloping terrain.