Characterisation of shearing behaviour at soil-structure interfaces is critical in the analysis and design of a wide range of geotechnical structures. Large-displacement ring shear interface testing employing pre-shearing stages has been recognised as a robust approach for characterising interface resistance, particularly when large rela-tive displacements are developed between soil and interface during either installation or operation. Such tests are applied in practical design approaches, for example in the ICP method for driven piles (Jardine et al., 2005). This paper presents a database of interface shearing tests involving sandy-silty materials, integrating outcomes from research and project studies conducted at Imperial College London (ICL) and the Norwegian Geotechnical Institute (NGI) using Bishop Ring Shear apparatuses. The outcomes enable a critical review of the potential effects of a wide range of factors, including: soil physical index properties (grading, fines con-tent); interface characteristics (mild/stainless steel, surface roughness); and applied testing conditions (shear rate and normal effective stresses). Trends identified from the datasets are integrated with previously reported studies to indicate the interface shear strength parameters that may be adopted for preliminary design with sandy-silty soils on the basis of simple index tests.
Liu et al. (2019) studied this question.