Shear strength characteristics of saturated montmorillonite and kaolinite clays

This paper deals with the shear strength characteristics of saturated, remoulded, montmorillonite and Kaolinite clays as affected by changes in soil structure. The changes in soil structure were made by changes in initial moulding water content, stress history and type of cation and its concentration in the electrolyte system. Throughout the investigation, isotropically consolidated undrained tests with pore water pressure measurements were conducted. The experimental results show a definite cohesion intercept even for saturated normally consolidated clays, under certain conditions. The modified effective stress concept, which takes into consideration the electrical attractive and repulsive forces appears to explain satisfactorily the strength mechanism. The qualitative analysis of the test data brings out the dire need for quantitative evaluation of electrical attractive and repulsive forces in order that a realistic determination of strength parameters could be made. The manifestation of components of shear resistance has also been discussed briefly