EFFECT OF FINES CONTENT ON SHEAR DEFORMATION PROPERTIES OF SAND SUBJECTED TO PORE WATER INFLOW AFTER UNDRAINED CYCLIC SHEARING

Abstract

 One of the factors that cause flow deformation with a time delay after an earthquake in gently sloping ground is the presence of pore water flowing into the sand layer directly below the impermeable layer from the lower layer. This is caused by the redistribution process of excess pore water pressure, which is increased by the excitation. Although the behavior of clean sand, in which shear deformation develops with volume expansion due to the inflow of pore water, has been experimentally investigated, few studies have focused on the effect of fines content. In this study, specimens with different fines content (F_c = 0, 10, 20, 30%) were prepared and subjected to undrained cyclic shear history after loading initial shear stress using a hollow torsion shear apparatus, followed by forced expansion shear test by pore water injection. As a result, it was found that the dilatancy characteristics of the specimens under porewater injection were affected by the fines content.