Mechanical Behavior of an Unsaturated Soil Under Multi-Axial Stress States
Macari EJ, Hoyos Jr. LR
(Received 14 June 1999; accepted 11 July 2000)

Abstract
A series of drained (constant suction) true triaxial tests has been conducted on several identically prepared, 10-cm side, cubical specimens of recompacted silty sand to study the stress-strain-strength behavior of an unsaturated soil under multi-axial stress states and suction-controlled conditions. The experiments were conducted in a stress/suction-controlled true triaxial (cubical) setup following a multi-stage testing scheme. Matric suction states in the specimens were induced and maintained constant during testing by using the axis-translation technique. Imposed stress paths included an initial hydrostatic compression followed by conventional triaxial compression, triaxial compression, or simple shear in the first octant of the octahedral stress plane. Test results are used to evaluate the nature of principal strain response of an unsaturated soil along multi-axial stress paths, and to observe the influence of matric suction on the shape, size, and position of the failure envelopes in the octahedral stress plane.

Keywords:
axis-translation technique, failure envelope, matric suction, multi-axial stress state, octahedral stress plane, soil, triaxial, true triaxial testing, unsaturated soils

Paper ID: GTJ2410014

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Author Macari EJ, Hoyos Jr. LR Title Mechanical Behavior of an Unsaturated Soil Under Multi-Axial Stress States Symposium , Committee on