Coupling Analyses of Limiting Equilibrium State for Normally Consolidated and Lightly Overconsolidated Soils

Abstract

ABSTRACT Limiting equilibrium state of saturated soils is solved taking into account drainage conditions during loading stage before reaching limit state. In analysis procedure, non-dilatant characteristics are assumed at limit state and then the failure problem discussed in the present study is concerned with normally consolidated and/or lightly over consolidated soils. When solving statically indeterminate limiting equilibrium state one needs constitutive relations at limit state. In saturated soils, however, since the constitutive relations are generally expressed in terms of effective stresses, an additional field equation is required in order to link a velocity field to a pore pressure field. Therefore the problem should be solved as a coupling problem between these two fields. Two distinct types are discussed, one is undrained problem and the other, fully drained problem. Topics covered in the present study are as follows: (1) Undrained bearing capacity and excavation stability of soft clays, (2) Bearing capacity under partly drained and/or partly swelling condition, (3) Comparison between rapid loading condition and undrained condition, and (4) Seepage failure of loose sandy soils under fully drained condition.