SIST EN ISO 17892-10:2019 PDF

Overview

EN ISO 17892-10:2018 - Geotechnical investigation and testing - Laboratory testing of soil - Part 10: Direct shear tests (ISO 17892-10:2018) specifies laboratory procedures to determine the effective shear strength of soils under consolidated drained conditions. The standard covers two direct-shear methods: the shearbox test and the ring shear test, applicable to undisturbed, remoulded, re‑compacted or reconstituted specimens. Tests are performed under a single vertical (normal) stress, generally using three or more specimens tested at different normal stresses to derive shear strength parameters (see Annex B).

Key topics and technical requirements

• Test methods: Detailed procedures for shearbox and ring shear devices, including the distinction that shearbox tests are typically used for peak strength while ring shear tests are commonly used for residual strength.
• Specimen preparation: Requirements for preparing specimens from undisturbed samples, trimming, extrusion and laboratory-fabricated specimens; preparation methods are provided but special procedures (staged loading, pre-shearing, and interface testing) are excluded.
• Apparatus and calibration: Specifications for shear devices, loading systems, load/torque and displacement measurement devices, plus Annex A covering calibration, maintenance and checks.
• Consolidation and shearing: Requirements for consolidation under the prescribed normal stress and controlled drained shearing; measurement and recording of stresses, displacements and volumetric changes during testing.
• Data, calculations and reporting: Reporting mandatory and optional test data, calculation of initial densities and void ratios, plotting results and deriving effective shear strength parameters (further calculations summarized in Annex B).

Practical applications

• Deriving effective cohesion (c') and effective friction angle (φ') parameters for geotechnical design.
• Use in foundation design, slope stability analyses, retaining wall design, embankment and earthworks assessments, tunnelling and underground works where drained shear strength is required.
• Determination of residual strength for fine-grained soils prone to strain softening, and assessment of interface shear strength where appropriate tests are performed (note: interface tests are not covered by this part).

Who should use this standard

• Geotechnical laboratories and testing technicians performing direct shear tests.
• Geotechnical engineers and consultants interpreting lab shear strength results.
• Research institutions developing soil strength models.
• Contractors and designers needing standardized, reproducible shear strength data for compliance with EN 1997‑1 and EN 1997‑2.

Related standards

• EN 1997‑1 and EN 1997‑2 (geotechnical design and investigation) - this document fulfills requirements for drained shear strength determination referenced by these Eurocodes.
• Other parts of ISO 17892 (laboratory soil testing series) for complementary test methods and soil property characterization.

Keywords: EN ISO 17892-10:2018, direct shear tests, shearbox, ring shear, effective shear strength, consolidated drained, laboratory testing of soil, geotechnical investigation.