Plasticity concepts are set forth in a rather general mamer for the treatment of soil as an isotropic strain-hardening or strain-softening material, and different assumptions are discussed for the derivation of incremental stress-strain relations. Strainsoftening flow laws violate Drucker's postulate, but it is shown how uniqueness can still be ensured by constraining the relative magnitude of the rate of strain softening with respect to the recoverable elastic energy of the material. The stability of the solution is discussed, and in order to illustrate the stability concepts, closed form solutions for the undrained expansion of a cylindrical cavity in a finite and infinite saturated medium are presented.
All Science Journal Classification (ASJC) codes
- Geotechnical Engineering and Engineering Geology
- Earth and Planetary Sciences (miscellaneous)