Stress-Strain Relationships of Sand after Liquefaction

The stress-strain relationships of sand after liquefaction were studied by conducting torsional shear tests under several conditions. A prescribed number of cyclic loadings were applied first, then a monotonic loading was applied in undrained condition. The stress-strain relationships during the monotonic loading are discussed. The stress-strain curves were affected by excess pore pressure ratio, soil density, confining pressure and severity of liquefaction. The shear modulus decreased to less than 111000 due to liquefaction, and shear strain increased more than 10% with very low stress in the liquefied specimen. And, there exists a so called reference strain at resistance transformation γL which increases with decreases in soil density and severity of liquefaction