Partial drainage characteristics of intermediate soils with low plasticity from Incheon, Korea

Abstract

According to the design code of construction for port and harbor facilities in Japan, ground that has sand size content between 50% and 80% is called intermediate soils, because of its intermediate behavior between sand and clay. Though intermediate soils with low plasticity are likely to be under partially drained conditions, stability analysis and evaluation of the shear strength for intermediate soil has been carried out based on undrained conditions. The drainage characteristics of the soil were estimated; that is, it was estimated whether the ground is under fully undrained conditions or partially drained conditions using CPTU data. The partially drained shear strength was estimated from the analysis of the distribution characteristics of CPTU based shear strength between the undrained shear strength line and the fully drained shear strength line, which was ranged approximately from φ'=5? to φ'=15°, similar to ranges of back analysis for the estimation of replacement depths.