Influence of Imperfect Saturation on Deformation Characteristics and Pore Water Pressure Buildup Under Cyclic Loading for Sand

Abstract

This paper presents an influence of imperfect saturation on undrained deformation behavior for sand. A torsional shear apparatus is newly modified and capable of undrained shear tests and measurements of S- and P-wave velocities for a saturated soil specimen. S- and P-wave velocities were measured for various partially saturated sand specimens, and P-wave velocity was found to be very sensitive to imperfect saturation. Undrained torsional shear tests were performed at various partially saturated conditions, measuring excess pore water pressure; this decreases significantly as the degree of saturation decreases. Nonlinear deformation characteristics were slightly influenced by B-value at the mean effective stress of 30 kPa.