A Microstructural Model for Soils and Granular Materials - Multiscale Geomechanics: From Soil to Engineering Projects - page 206

e ref p ref (kPa) m

λ φ μ (°) φ 0 (°)

1.08 10.00 0.11 38.00 38.00 1.00

Table 7.6. Model parameters for the decomposed granitic soil

After applying an initial suction of 40 kPa, unsaturated samples were
isotropically compressed and then sheared at constant water content. Figure 7.17
presents the results obtained for three different confining pressures, 50 kPa, 100 kPa
and 150 kPa, on specimens with the same initial void ratio e 0 = 1.09. The results
show a constant increase in deviatoric stress up to a constant value for axial strain
over 25%. The deviatoric stress increased with the applied mean stress. The three
specimens exhibited a contractive volumetric behavior, with higher contraction for
the specimen subjected to higher confining stress.

Figure 7.17. Triaxial tests at constant water content on unsaturated silty sand