Abstract
The paper compares the pre-failure behavior of granular soils investigated in the classical triaxial apparatus and in the true triaxial apparatus, under plane strain conditions. Both experiments are described within the framework of an incremental model of the pre-failure behavior of sands. The methods of tensor algebra are used to compare theoretical predictions with experimental results. The analysis presented deals with the pre-failure deformations of fully drained sand, as well as with its undrained behavior, including static liquefaction and the specific behavior of an initially dilative soil. Some key questions of soil mechanics are discussed, for instance, whether soil parameters determined from one configuration, such as triaxial conditions, can be applied in other cases.