ABSTRACT
Soils of interest for slope instability are inherently subjected to initial shear stress. In order to examine the characteristics of undrained flow behaviour of such soils, undrained triaxial compression tests are carried out on isotropically as well as anisotropically consolidated soil specimens. The degree of anisotropic consolidation is defined by Kc (=σ3c’/σ1c’). The two soil materials are used in this study; Omigawa silty sand and Jamuna river silty sand. The steady state and phase transformation envelopes are found to be uniquely determined independently of the Kc values, in the plot of effective mean stress p′ against shear stress q, however, there are a series of peak stress state envelopes for different Kc values. The steady state and phase transformation lines are examined in (e, p′) and (e, q) plots. The flow characteristics of anisotropically consolidated soil specimens are then examined with the initial state ratio rc.
