Non-linear seismic response and liquefaction

The essential cause of the growth of pore pressure during cyclic loading is identified as an ‘autogenous’ shrinkage or densification of the solid phase of the soil and this is related to a strain path parameter. Introduction of this ‘shrinkage’ coupled with an elasto-plastic behaviour of the soil skeleton allows a full non-linear dynamic analysis to be conducted up to the point of structural failure for any earthquake input. Explicit time marching procedures are used. The procedure outlined is applicable to all problems of complex geometry and for conditions of undrained or partially drained behaviour at a moderate computational cost.