Numerical Modeling of Nonhomogeneous Behavior of Structured Soils during Triaxial Tests

The nonhomogeneous behavior of structured soils during triaxial tests has been studied using a finite element model based on the Structured Cam Clay constitutive model with Biot-type consolidation. The effect of inhomogeneities caused by the end restraint is studied by simulating drained triaxial tests for samples with a height to diameter ratio of 2. It was discovered that with the increase in degree of soil structure with respect to the same soil at the reconstituted state, the inhomogeineities caused by the end restraint will increase. By loading the sample at different strain rates and assuming different hydraulic boundary conditions, inhomogeneities caused by partial drainage were investigated. It was found that if drainage is allowed from all faces of the specimen, fully drained tests can be carried out at strain rates about ten times higher than those required when the drainage is allowed only in the vertical direction at the top and bottom of the specimen, confirming the findings of previous studi...

[1]  G. Mesri,et al.  Composition and compressibility of typical samples of Mexico City clay , 1975 .

[2]  J. H. Atkinson,et al.  Non-uniformity of triaxial samples due to consolidation with radial drainage , 1985 .

[3]  Antonio Gens,et al.  Critical state models in computational geomechanics , 1988 .

[4]  J. Carter,et al.  A structured Cam Clay model , 2002 .

[5]  À. Balla.  Stress Conditions in Triaxial Compression , 1960 .

[6]  R. Nova,et al.  An experimental and theoretical study of the behaviour of a calcarenite in triaxial compression , 1995 .

[7]  John P. Carter,et al.  Predictions of the non-homogeneous behaviour of clay in the triaxial test , 1981 .

[8]  Kenneth L. Lee.  END RESTRAINT EFFECTS ON UNDERAINED STATIC TRIAXIAL STRENGTH OF SAND , 1978 .

[9]  J. C. Small,et al.  Elasto-plastic consolidation of soil , 1976 .

[10]  Kennet Axelsson,et al.  Effects of end restraint and strain rate in triaxial tests , 1997 .

[11]  Andrew J. Whittle,et al.  Evaluation of a constitutive model for overconsolidated clays , 1993 .

[12]  A. Saada,et al.  State of the Art: Laboratory Strength Testing of Soils , 1981 .

[13]  James K. Mitchell,et al.  Time‐Dependent Strength Gain in Freshly Deposited or Densified Sand , 1984 .

[14]  D. Potts,et al.  SUBSIDENCE ABOVE THE EKOFISK OIL RESERVOIRS , 1988 .

[15]  L. Jacques,et al.  The compressibility and sensitivity of an artificially sedimented clay soil: The Grande‐Baleine Marine Clay, Québec, Canada , 1985 .

[16]  Local strains and displacement patterns in triaxial specimens of a saturated clay. , 1976 .

[17]  N. Kalteziotis,et al.  Geotechnical properties of the Corinth Canal marls , 1991 .

[18]  Angelo Amorosi,et al.  A constitutive model for structured soils , 2000 .

[19]  P. R. Vaughan,et al.  The general and congruent effects of structure in natural soils and weak rocks , 1990 .

[20]  K. Roscoe,et al.  ON THE GENERALIZED STRESS-STRAIN BEHAVIOUR OF WET CLAY , 1968 .

[21]  Mohamed Rouainia,et al.  A kinematic hardening constitutive model for natural clays with loss of structure , 2000 .

[22]  A. Bishop,et al.  The Influence of End Restraint on the Compression Strength of a Cohesionless Soil , 1965 .

[23]  James M. Duncan,et al.  The Significance of Cap and Base Restraint , 1968 .