Study on φ’ of normally consolidated marine clay using simple CU test

Abstract

The simplified CU test is a test to determine the strength of seabed clay soil, and is a triaxial CIU test in which a clay sample is isotropically consolidated at 2/3 of the in-situ effective overburden pressure σ_v0’. From a series of laboratory test, of Tokyo Bay marine clay with overconsolidation ratio of 1.00-2.77, the internal friction angle φ’_SCU obtained with c’ = 0 in the simple CU test was compared with the internal friction angle φ’_NC obtained by the triaxial CIU test consolidating to the normal consolidation state. Regarding the representative valueφ’_NC(AVG.), the relationships φ’_NC(AVG.)=(0.75-0.95)φ’_SCU and φ’_NC(AVG.)=(0.85-1.05) φ’_SCU were obtained for the highly plastic clay layer with a liquidity limit of 100% or more and for the low-plasticity clay with a liquidity limit of 60% or less, respectively.