Influence of End Restraint in Cyclic Triaxial Tests.

摘要

Theoretical considerations concerning the effect of end restraint on the strength of soil in triaxial tests are briefly discussed herein. The theoretical aspects are supplemented by a review of all laboratory tests data available to the writer. Most of the data pertain to static drained tests on sands. There are also data from static undrained tests on saturated clays. A lesser amount of previously unpublished data from the writer's files on static and cyclic loading undrained tests on saturated sands are also included. The theoretical considerations and the available data are all consistent within themselves in demonstrating and explaining the significant conclusions which follow directly from basic considerations of the behavior of soil under various loading conditions. End restraints, such as are found in most ordinary triaxial test equipment, prevent lateral strains at the ends of the specimen and thereby lead to nonuniformities and concentrations in the stresses and strains throughout the specimen. As a result, volume changes in soils which dilate strongly when sheared will be affected. If tested undrained, this will be reflected by variations in pore pressure from that associated with uniform stress and strain distributions throughout.