ISO 17892-9:2018 specifies a method for consolidated triaxial compression tests on water-saturated soils.

ISO 17892-9:2018 is applicable to the laboratory determination of triaxial shear strength under compression loading within the scope of geotechnical investigations.

The cylindrical specimen, which can comprise undisturbed, re-compacted, remoulded or reconstituted soil, is subjected to an isotropic or an anisotropic stress under drained conditions and thereafter is sheared under undrained or drained conditions. The test allows the determination of shear strength, stress-strain relationships and effective stress paths. All stresses and strains are denoted as positive numerical values in compression.

NOTE 1 This document provides a test for a single specimen. A set of at least three relatable tests are required to determine the shear strength parameters from these tests. Procedures for evaluating the results are included in Annex B and, where required, the shear strength parameters are to be included in the report.

Special procedures such as:

a) tests with lubricated ends;

b) multi-stage tests;

c) tests with zero lateral strain (K0) consolidation;

d) tests with local measurement of strain or local measurement of pore pressure;

e) tests without rubber membranes;

f) extension tests;

g) shearing where cell pressure varies,

are not fully covered in this procedure. However, these specific tests can refer to general procedures described in this document.

NOTE 2 This document fulfils the requirements of consolidated triaxial compression tests for geotechnical investigation and testing in accordance with EN 1997‑1 and EN 1997‑2.