A new theory for membrane efficiency coefficient of compacted clay

Abstract

A new method for calculation the membrane efficiency coefficient w of compacted clay is proposed in this paper. The influence of fixed negative charge on the surface of clay minerals is considered. What’s more, the change of porosity during deformation is considered. Based on the chemical potential of specimens, the true ion concentration in pore-water is obtained. Based on the true ion concentration in pore water, the disjoining pressure considering fixed negative charge inside soils and the change of void ratio is proposed. A new calculation method for the membrane efficiency coefficient of compacted clay is established. The test data of w considering different porosity are calculated and the calculated results are compared with the traditional calculation methods. The new calculation methods of w provide a more physical-based theory for environmental geotechnical engineering.