Effects of cone tip roughness, in-situ stress anisotropy and strength inhomogeneity on CPT data interpretation in layered marine clays: numerical study

The results have shown that the noted factors have significant influence on net cone penetration resistance in stratified deposits. These influences in the layered deposits were found to be similar in magnitude to those on the cone limiting resistance in a single clay layer, leading to the resultant influence on a thin layer correction factor for cone penetration resistance minimal. This was confirmed by the evidence of the evolving soil flow mechanisms around the cone tip. Therefore, the design charts and formulas developed for a smooth cone in uniform three-layer soils are applicable for delineating layer boundaries and interpreting the undrained shear strength of each identified layer for a partially rough cone in three-layer non-homogeneous clay deposits. However, the cone tip roughness factor was shown to have an influence in the layer boundary identification, especially for the cone penetration from a stiff layer to a soft layer.