Shear strength and yield surface of a partially saturated sandy silt under generalized stress states

This paper studies the hydromechanical behavior of a slightly compacted mixture sand and clayey silt (30%/70%) under generalized stress state. The experimental study focused on analyzing yielding response shear strength at different states (characterized by intermediate principal parameter b, or Lode angle) initial total suctions (as-compacted state). For investigation, hollow cylinder apparatus was used. results allowed defining variation critical state line with angle suction. Different models were proposed for isotropic anisotropic yield surfaces, their shape rotation calibrated results. modeled surfaces fitted reasonably well results, considering inclination dependence suction, mean deviatoric stresses, angle. In addition, some relationships between stresses model parameters to normalize surface equation.