Shear Failure Criterion Based on Experimental and Modeling Results for Fiber-Reinforced Clay

The present paper deals with an experimental study and an analytical model set up to predict the shear resistance of clay reinforced by short fibers in plane strain and axisymmetric cases. The primary theoretical framework of this study is an extension of the Michalowski model, which is applied to reinforced sandy soils. According to the experimental findings, the failure of soil composite material is caused by slippage of the fibers. Thus, interface behavior between single fibers and the clay has been investigated by means of pullout tests. Taking into account the fiber content, interface behavior, and soil failure criterion, a model that enables the prediction of the failure of clay/fiber composite has been produced. The comparison with the results of undrained triaxial compression tests performed on reinforced clay has shown that the axisymmetric model is best suited for reproducing the failure criterion of the reinforced material.