Behavior of Fine Sand Under Cyclic Rotation of Principal Stresses Using the Hollow Cylinder Apparatus

Results of an experimental investigation on a saturated fine Ottawa Silica Sand subjected to three different types of cyclic tests are presented in this paper. The effects of principal stress rotation at a constant deviator stress on the pore water pressure buildup and the deformation characteristics of sand are evaluated in comparison with results from cyclic triaxial and cyclic torsional simple shear using the hollow cylinder apparatus. The results presented and discussed in this article, representing a small part of the experimental program, suggest that the effects of rotational shear are more important than the effects of cyclic triaxial loading or cyclic torsional simple shear loading (of the same amplitude) in terms of the rate of pore water pressure buildup, the triggering of a liquefaction flow failure in contractive sand and the rate of accumulation of plastic deformation. Moreover, results from the monotonic test program on fine Ottawa Silica Sand under drained conditions were found in very good agreement with the failure surface incorporated in Lade's constitutive model for frictional materials.