Measurement of Residual/Remolded Vane Shear Strength of Marine Sediments

The measurement of both residual and remolded shear strength using the vane shear apparatus is discussed. Residual shear strength is defined to be measured after 90° of vane rotation. In contrast, remolded shear strength is dependent on whether it is measured by vane remolding or hand remolding. To accomplish vane remolding, a minimum of three vane revolutions are required. The relative strengths of the various remolding methods show that (1) field vane remolding gives highest strength, (2) followed by either laboratory vane remolding or hand remolding. Order of the last two appears to depend on soils plasticity. Vane remolding is shown to be influenced by a soils anisotropy while hand remolding is not. Case studies are presented for a DSDP site in the North Pacific and the Mississippi Fan in the Gulf of Mexico. Standardization and measurement procedures to obtain repeatable and comparable results are presented.