The shear strength of soil is a crucial property that is difficult to measure in unsaturated soils. It requires several tests and a long time to establish the strength variation with matric suction. Predictive models can be utilized to evaluate the unsaturated shear strength of heaving soil. The research aims to develop models to determine the shear strength parameters of partly saturated soils, including the angle of increase in shear strength with matric suction, the angle of internal friction related to net normal stress, and effective cohesion. Soil properties were evaluated using various tests such as particle size distribution, specific gravity, consistency limits, swelling test, modified Proctor compaction test, suction test, and advanced triaxial testing. Regression analysis was performed to develop predictive models using MINITAB 20 Software. The validation process includes p-value, determination coefficient, comparing predicted with experimental values, and comparing other models in literature with models developed in this study. The developed models can estimate the shear strength characteristics of compacted, unsaturated soils with acceptable precision.
Author(s) Details:
Armand Augustin Fondjo,
Department of Civil Engineering, Faculty of Engineering, Built Environment & Information Technology, Central University of Technology, Free State, South Africa.
Elizabeth Theron,
Department of Civil Engineering, Faculty of Engineering, Built Environment & Information Technology, Central University of Technology, Free State, South Africa.
Richard P. Ray,
Structural and Geotechnical Engineering Department, Széchenyi István Egyetem University, 9026 Gyor, Egyetem Tér 1, Hungary.