Drained behaviour of Changi sand in triaxial and plane-strain compression

Many geotechnical problems are under plane-strain conditions. However, geotechnical designs still rely largely on testing data obtained under axisymmetric conditions. Therefore a good understanding of the similarities and differences between the strength and deformation behaviours of soil under plane-strain and axisymmetric conditions is important. Experimental data obtained from drained triaxial and plane-strain tests on very loose and medium dense sand are presented in this paper. The strength and deformation characteristics of the sand under plane-strain conditions are studied and compared with those under axisymmetric conditions. The results show that the failure envelope on the [image omitted] plane under plane-strain conditions is below that under axisymmetric conditions, although the friction angle under plane-strain conditions is higher than that under axisymmetric conditions. The critical state line and the stress-dilatancy relationship under plane-strain conditions are also different from those under axisymmetric conditions.