The use of stress discontinuities in drained plasticity calculations
If a soil at failure is assumed to be deforming plastically with full dissipation of excess pore pressure permitted, simple solutions to stability problems can often be obtained by ensuring that, at any point within the soil mass, effective stress equilibrium is satisﬁed and the effective stress failure criterion is not violated. These solutions give a lower bound on the applied loading. As with undrained solutions, discussed in Chapter 6, it is necessary to assume for most problems one or more changes in the stress field to satisfy boundary conditions. This can be accomplished by inserting effective stress discontinuities within the deforming mass.