Stress-Strain Behavior of a Granular Fill Measured by a New Plane-Strain Apparatus

In this paper a new plane-strain apparatus is described. The main feature of the plane-strain apparatus is that the intermediate principal stress can be measured by four submersible pressure transducers. Experimental data obtained from drained tests on very loose to medium dense sand are presented. The strength and deformation behavior of the sand under plane-strain conditions and shear band formation are studied. The results show that the failure envelope obtained from plane-strain tests is lower than that from triaxial tests. However, in terms of friction angle, the value obtained from plane-strain tests is higher than that from triaxial tests. The critical state line obtained under plane-strain conditions is also different from that under axisymmetric conditions. Under plane-strain conditions, shear bands occur for medium loose to dense specimens. However, no visible shear bands are observed for very loose specimens. This is consistent with the study reported by Han and Vardoulakis (1991) but different from that by Finno et al. (1996, 1997).