Experimental study on nonlinear shear strength behavior of a tropical granitic residual soil (Grade VI) at various initial moisture contents

The conventional theories of soil mechanics use linear envelope to derive shear strength; this however, leads to an overestimation of the factor of safety in the examination of slopes. Therefore, the incorporation of methods that acknowledge the existence of non-linear characteristics of shear strength is necessary in the analysis of slopes specifically. This is due to the substantial influence of non-linear shear strength behavior on the slope failure mechanism when they are at low stress levels. In this paper, the nonlinearity of shear strength for grade VI granitic residual soil is studied. “Non-Axis Translation Consolidated Drained Triaxial” tests were performed at various ranges of net stress and suction. Thereafter, to characterize shear strength behavior, shear strength parameters were derived. The soil-water characteristic curve was plotted after conducting “Pressure Plate Extractor” test at a series of suction. The result substantiated the non-linearity of shear strength for granitic residual soil based on net stress and suction.