Characterizing shear properties of fine-grained subgrade soils under large capacity construction equipment

Abstract

The routine operations of large capacity off-road construction equipment on fine-grained cohesive soils have become a concern to the construction and equipment manufacturing sectors due to problems with mobility on these soils. In this study, both monotonic and cyclic triaxial tests were conducted to determine shear properties of a fine-grained subgrade soil at the optimum moisture content and 3% above and below the optimum. The complete test results provided an extensive database of material properties including friction angle and cohesion for strength properties and shear modulus of the soil at three moisture states. Mohr-Coulomb failure models were developed together with shear modulus correlations for the soil sample. These models can be used for evaluating the impact of moisture on shear strength and stiffness behaviour of fine-grained soils with similar characteristics for their sustainable use in construction applications.