Fundamentals Of Plasticity In Geomechanics Pdf Jun 2026

Standard metal plasticity models like Von Mises or Tresca fail in geomechanics because they ignore pressure-dependence. Soil and rock require shear strength models that scale with confining pressure.

Understanding plasticity in geomechanics is essential for designing safe civil engineering structures. It allows engineers to predict the failure of foundations, the stability of slopes, and the collapse behavior of underground excavations. Elastic vs. Plastic Behavior Elastic Deformation

: The stress state is on the yield surface (Plastic yielding is occurring). fundamentals of plasticity in geomechanics pdf

: Second invariant of the deviatoric stress tensor (represents shear stress)

The ultimate goal of deformation in geomechanics is the . At this state, continuous shear distortion occurs under constant effective stress and constant volume. Plasticity models incorporate critical state parameters to define the line toward which all stress paths converge during failure. Standard metal plasticity models like Von Mises or

The yield criterion is a scalar function, typically denoted as

The yield surface expands uniformly in all directions, indicating an increase in material strength. It allows engineers to predict the failure of

The Drucker-Prager model smooths out the sharp corners of the Mohr-Coulomb criterion. It represents a smooth, right-circular cone in principal stress space.

. The plastic strain is orthogonal to the yield surface. This overestimates soil dilation.

: These describe how the yield surface evolves (expands or shifts) as plastic deformation occurs. In geomechanics, this is often linked to changes in void ratio or plastic volumetric strain (e.g., the Cam-Clay model ).