ISO 17892-6:2017
Geotechnical investigation and testing — Laboratory testing of soil — Part 6: Fall cone test
Geotechnical investigation and testing — Laboratory testing of soil — Part 6: Fall cone test
- Статус документа:
- Действующий
- Формат:
- Электронный (PDF)
- Количество страниц:
- 11
- Дата публикации:
- 3 марта 2017 г.
- Издание:
- ISO IS 17892 edition 1 version 1
- ICS:
- 13.080.20
ISO 17892-6:2017 specifies a method of undrained strength index testing of both undisturbed and remoulded specimens of fine grained soils by the fall cone method. ISO 17892-6:2017 is applicable to the laboratory estimation of undrained shear strength of a soil test specimen within the scope of geotechnical investigations. In the fall cone test, a cone is allowed to fall with its tip towards a soil specimen, and the resulting penetration of the cone into the soil is measured. The penetration values are used to estimate the undrained shear strength. The fall cone test produces a complex shear in the test specimen, and does not represent either a vertical triaxial compression or a horizontal shear test. However, this index test may be correlated to some estimate of undrained shear strength determined in the laboratory by other test methods. As the test is performed on a small laboratory specimen, the result may not agree with laboratory tests on larger specimens. In addition, the test specimen may not be fully representative of the soil in its natural state in the field; for example, the test specimen may not have fissures present in situ at a larger spacing than the specimen size. Therefore, for the above reasons, the test can be regarded as an estimation of undrained shear strength, rather than a true measurement of it. The ratio of the remoulded shear strength to the undisturbed shear strength may be used to estimate the sensitivity of a soil specimen. Time-dependent measurement of the shear strength may be used to assess the thixotropic regain of strength of a remoulded soil specimen. NOTE This document fulfils the requirements of the strength index testing of soils for geotechnical investigation and testing in accordance with EN 1997?1 and EN 1997?2.
Abstract
Overview
ISO 17892-6:2017 - "Geotechnical investigation and testing - Laboratory testing of soil - Part 6: Fall cone test" specifies a standardized laboratory method for estimating the undrained shear strength of fine‑grained soils using the fall cone test. The standard covers testing of both undisturbed and remoulded specimens, describes equipment and specimen preparation, measurement procedures, reporting and calibration requirements, and notes limitations when correlating results with other laboratory strength tests.
Key topics and technical requirements
- Scope: Index method for estimating undrained shear strength of fine‑grained soils; results are estimations and may not equal strengths measured on larger specimens or in situ.
- Test principle: A cone is released to fall into a soil specimen; cone penetration is measured and used to estimate undrained shear strength.
- Equipment:
- Penetration measurement range of at least 4 mm to 20 mm (manual scale or electronic transducer).
- Fall cones with typical total masses and tip angles (examples: 10, 60, 80, 100, 400 g; tip angles 30° or 60°).
- Cones: corrosion‑resistant, polished (average roughness Ra < 0.8 µm); mass within ±1%; tip angle within ±0.2°; geometrical tip deviation < 0.1 mm; max wear < 0.3 mm.
- Specimen requirements:
- Undisturbed specimen diameter ≥ 50 mm, height ≥ 25 mm.
- Remoulded specimens prepared in rigid, non‑corrodible cups (≥ 50 mm diameter, 25 mm depth).
- Test spacing and repetition:
- Penetration zones ≥ 7 mm from specimen edge; test point spacing ≥ 14 mm.
- Derived indices:
- Fall cone undrained shear strengths for undisturbed (c_ufc) and remoulded (c_urfc) specimens.
- Sensitivity estimated as ratio c_urfc / c_ufc.
- Time‑dependent measurements for assessing thixotropic strength regain.
Applications and who uses it
ISO 17892-6 is used in geotechnical investigations, laboratory testing programs, and research where rapid index estimates of undrained shear strength are required. Typical users:
- Geotechnical engineers and consultants performing site investigations
- Laboratory technicians conducting soil strength index tests
- Researchers studying sensitivity, thixotropy, or soil behavior
- Contractors and designers needing quick undrained strength estimates for foundation and slope assessments
Related standards
- ISO 17892-1 (Determination of water content)
- ISO 14688-1 (Identification and classification of soil)
- EN 1997-1 and EN 1997-2 (Eurocode 7 references for strength index testing)
Keywords: ISO 17892-6, fall cone test, undrained shear strength, geotechnical investigation, laboratory testing of soil, fine‑grained soils, sensitivity, thixotropic.
Технические детали
- Технический комитет
- ISO/TC 182 - Geotechnics
- SKU
- ISO 17892-6:2017
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