Abstract:
This paper summarizes the experimental results of a study conducted in
order to investigate the effect of initial static shear on the undrained cyclic behavior of
saturated sand under cyclic torsional shear loading up to single amplitude shear strain of
about 50 (~o. Several hollow cylinder specimens at relative density of about 45 % were
performed with varying the initial static shear and the subsequent cyclic hear stress
levels. The observed failure behavior of specimens could be distinguished into
liquefaction and residual deformation failures depending on the magnitude of' combined
static and cyclic shear stress. In addition. it was found that the presence of static shear
does not always lead to an increase in the resistances to liquefaction and strain
accumulation. They could either increase or decrease with increasing the static shear
depending 011 the magnitude of combined shear stress, the type of loading and the failure behavior.
