ABSTRACT
The stress-strain relationships of sand after liquefaction were studied by conducting torsional shear and triaxial compression tests under several conditions. A prescribed number of cyclic loadings were applied first, then a monotonic loading was applied in undrained conditions. The stress-strain curves were affected by the accumulated excess pore pressure ratio and by the severity of liquefaction. The shear and secant modulus decreased to less than 1/1000 due to liquefaction. The 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, " which increases with decreases in soil density, severity of liquefaction and fines content, and with increase with confining pressure.(AU)