EFFECTS OF LOCALIZATION IN TRIAXIAL TESTS ON CLAY. PROCEEDINGS OF THE ELEVENTH INTERNATIONAL CONFERENCE ON SOIL MECHANICS AND FOUNDATION ENGINEERING, SAN FRANCISCO, 12-16 AUGUST 1985

The importance of distinguishing between two principally different types of failure, which develop under and as a consequence of different strain conditions in triaxial tests on clay is pointed out. A line failure will develop under conditions of nonuniform strain states in the test specimen, whereas a zone failure, in which multiple slip planes traverse the clay specimen, will develop under conditions of macroscopically uniform strain states in the specimen. The two types of failure will generally yield different types of behavior. Series of tests were conducted on remolded clay with overconsolidation ratios of 1, 2, 5 and 15. The tests were performed in triaxial compression and triaxial extension on specimens with line failure and with zone failure. The difference in behavior is most pronounced in triaxial extension tests. It is concluded that comparisons of stress-strain, undrained stress-path, and strength characteristics obtained under different stress conditions should only be made if these have been obtained under the same strain and failure conditions, preferably those of uniform strains and consequent zone failure. For the covering abstract of the conference see IRRD 287689. (Author/TRRL)