Abstract:

Large deformation may occur in the post initial liquefied sand undergone the dynamic loading. The definitions of shear strain rate and apparent viscosity in fluid mechanics are introduced to analyze the dynamic hollow torsional tests of post initial liquefied sand. There are two states in the post liquefied sand: zero effective stress state and non-zero effective stress state. The conclusions show that the sand characterized by shear-thinning non-Newtonian fluid in zero effective stress state which is similar to the static torsional tests. The loading cycle number does not have influence on the shape of flow curves under shear–thinning state except for the amplitude of shear strain rate, which increases with the increase of cycle number. Under non–zero effective stress state, the apparent viscosity increases with the increase of strain and the decrease of pore pressure. The apparent viscosity, which obtained from all tests, has a unitary formulation with the pore pressure ratio.

Key words: post initial liquefaction, dynamic hollow torsional test, sandy soil, fluid, flow characteristics, viscosity, shear strain rate