Liquefaction responses of specimens prepared by ips tested in dss-c and shaking table

In this study, the liquefaction responses of partially saturated sand samples prepared by Induced Partial Saturation (IPS) technique were investigated on small-size specimens tested in dynamic simple shear test device with confining pressure (DSS-C) and compared to the published findings from large-size specimen tests performed on shaking table. The small-size specimens were prepared at 70–87% degrees of saturation (S). The tests were performed under 50–150 kPa vertical effective stresses (σ′_v) where equal amount of back pressure (u₀) was applied. Shaking table tests were performed by Eseller-Bayat et al. (2013) on large-size specimens with S=60–80% and excess pore water pressures were measured under σ ′_v=2–3 kPa. In both experimental setups, shear strain amplitudes (γ) were kept constant at 0.1–0.2%. As a comparison of strain controlled liquefaction tests, excess pore water pressure ratio (r_u) increased with number of cycles (N) and stabilized at a maximum value (r_u,max) which was less than 1.0 in large-size specimens. However, in small-size specimens, r_u was increasing with increasing N and did not stabilize at a constant r_u,max value.