Strain softening of unsaturated swelling clays

摘要

Triaxial compression tests, direct shear tests and compaction tests are carried out on several blend samples of Toyoura standard sand, kaolinite and montmorillonite to investigate strain hardening and softening characteristics. Through the laboratory test result using above clayey soils, remarkable plastic flow during loading has been recognized especially in montmorillonite content samples, so that the plastic flow phenomena are evaluated based on a constitutive equation proposed by Richard - Abbott. The test specimen's behavior is a new evidence that supports the theory. The relationship between mechanical properties are also investigated with connection of soil physical properties. Several new relationships among parameters derived from different tests will be proposed as a function of strength and physical parameters of unsaturated swelling clays.