Study on Impact of Clay Minerals on the Characteristics of Volume Changes of Heavy Soils

Clay minerals can absorb water and incorporate it into its microstructure. During these processes (water absorption or loss), volume changes occur in clay particles. High content of clay particles in soils can lead to their volume changes, provided there are simultaneous changes in moisture. Volume changes of heavy soils occuring during shrinking and swelling processes are important because they are accompanied with soil surface shrinkage and cracks formation. Formation and dynamics of cracks have an important impact on transport processes in heavy soils and consequently on their water regime. The presented chapter describes the results of the analysis of the influence of clay content on the coefficient of linear extensibility (COLE), potential of linear extensibility (PLE) and geometric factor of soils. The hypothesis about the influence of texture on the value of the volume change potential and the geometric factor, and thus on the degree of distribution of volume changes on the vertical and horizontal components, was verified. The hypothesis assumes that the clay soil component has the greatest influence on the potential of volume changes and on the geometric factor value. New information is obtained on the basis of field and laboratory measurements. Results will be used as inputs for numerical simulation of water regimes of heavy soils.