A thesis submitted in partial fulfillment of the requirements for t h e degree of Master of Engineering, School of Engineering and Technology

Thesis (M.Eng.) - Asian Institute of Technology, 1989

In this study the yield locus and stress strain relationship of very soft and medium soft Muar Clay <Malaysia> are studied experimentally by loading the clay samples along different constant stress ratio paths under axisymmetric triaxial condition. From these tests the experimental yield locus were determined and compared with the existing theoretical models such as Cam Clay and Modified Cam Clay. A mathematical model according to WONG & MITCHELL (1975> was also formulated using experimentally defined flow rule. The yield locus determined from the tests has skewed elliptical s hape with axis approximately on the K0 line. The plastic potential surface is elliptical in shape with minor axis on the p axis. Constant p tests were conducted to compare predictions given by the results of stress strain relationship to failure with the above described theoretical models as well as Pender' s model. From comparison it is noted that the Pender' s model predicts well the shear strains for lightly overconsolidated specimens. While the Modified Cam Clay model give a better prediction on normally consolidated specimens.