An experimental and theoretical study of the behaviour of a calcarenite in triaxial compression

An experimental and theoretical investigation on the behaviour of a calcarenite subjected to various axisymmetric loading programmes is reported, The essential feature of the observed behaviour is the occurrence of a destructuration phase, which marks the transition from rock-like to soil-like behaviour, During this phase the state of stress remains constant, while strains increase steadily, Three phases can be distinguished: an initial elastic, a destructuration phase and a hardening or softening phase which ends on an ultimate state locus which is linear in the p'-q plane, The observed behaviour is more and more ductile for increasing confining pressures, In the softening regime the specimen is unstable, It is shown that by means of a mathematical model based on the theory of strain-hardening plasticity it is possible to describe mathematically the overall behaviour of the calcarenite in various types of triaxial compression test, Qualitative and quantitative accuracy is generally satisfactory, especially for drained tests at high confining pressures and oedometric loading, For low confining pressures agreement between calculated and observed data after peak is much less satisfactory.