🏗️ Determination of the compressibility and consolidation characteristics of soils in an oedometer by incremental vertical loading — cylindrical specimen in a rigid ring (diameter ≥ 35 mm, height ≥ 12 mm, D/H ≥ 2,5), axial drainage through porous discs at top and bottom, load increments held to an accuracy of 1 % or 1 kPa (the mechanism should allow an increment to be applied within 2 s), settlement measured with a resolution of 0,01 % and an accuracy of 0,1 % of the height, vertical strain, void ratio, compression–stress diagram, PN-EN ISO 17892-5

Construction PN-EN ISO 17892-5

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN ISO 17892-5:2017-06 (Polish version), in full (our translation): “This document specifies methods for determining the compressibility characteristics of soils by incremental loading in an oedometer. This document applies to the laboratory determination of the compressibility and deformation characteristics of soils within the scope of geotechnical investigation. The oedometer test is carried out on a cylindrical test specimen confined laterally by a rigid ring. The specimen is subjected to stepwise increments of vertical axial loading or unloading. Axial drainage of water from the upper and lower surfaces of the specimen is possible. Tests can be carried out on specimens of undisturbed structure, remoulded, recompacted or reconstituted specimens. Stress paths and drainage conditions in foundations are generally three-dimensional and differences may occur in the calculated values of both the magnitude and the rate of settlement. Usually specimens of small size do not reflect the structures present in natural soils. The analysis of consolidation tests is generally based on the assumption that the soil is saturated. For unsaturated soils some of the derived parameters may not be appropriate. NOTE This document fulfils the requirements for determining the compressibility properties of soils in the oedometer for geotechnical investigation and testing according to EN 1997-1 and EN 1997-2.” We read the text of the standard in the preview of ISO 17892-5:2017 from the cover to 6.2.2.2 (page 6); we do not have the rest of specimen preparation, assembly, loading (6.4–6.6), results (7), test report (8) or Annexes A and B — we only know their titles from the table of contents.

ACCORDING TO THE TEXT OF ISO 17892-5:2017 (foreword, introduction, Clauses 1–6.2.2.2, table of contents). The standard was prepared by CEN/TC 341 together with ISO/TC 182 (Vienna Agreement); the first edition replaces ISO/TS 17892-5:2004 after technical revision and incorporates Cor 1:2006. Scope (1) — as on the card. References (2): ISO 14688-1, ISO 17892-1, -2 and -3. Definitions (3): excess pore pressure (difference from the equilibrium pore pressure at the end of consolidation); primary consolidation — decrease of void ratio by increase of effective stress as excess pore pressure dissipates under constant load (rate controlled mainly by drainage conditions); secondary compression — independent of excess pore pressure dissipation (controlled by factors other than drainage); swelling; swelling pressure — pressure needed to keep constant volume when the soil is flooded with water. Symbols (4): among others e₀ and ef (initial void ratio and at the end of an increment), H₀, Hi, Hf, Hs (equivalent height of solids), md, w₀, εv,f (vertical strain, compression positive), ρ, ρd, ρs, σ′v (kPa). Equipment (5, calibration according to Annex A): corrosion-resistant ring with a sharp cutting edge, diameter not less than 35 mm, height not less than 12 mm, D/H ratio not less than 2,5, smooth (may be lubricated with silicone grease or petroleum jelly), laterally confined or stiff enough that the diameter does not expand by more than 0,05 % under the maximum horizontal stress; corrosion-resistant porous discs allowing free drainage without intrusion of particles, of negligible compressibility (filter paper of sufficient permeability if needed), top disc smaller than the ring by 0,2–0,5 mm and larger than 85 % of the loading cap diameter; fixed-ring and floating-ring oedometers (Figure 1); new discs are boiled in distilled water for at least 20 min, used ones cleaned with a brush and checked for permeability, kept immersed in water, and for soils readily absorbing water (e.g. stiff clays) air-dried immediately before use; watertight cell with water above the top disc; rigid loading cap with perforations or grooves; deformation measurement with a resolution of at least 0,01 % and an accuracy of at least 0,1 % of the initial height (dial gauge or electrical transducer); loading frame acting centrally, stress accurate to 1 % of the intended value or 1 kPa (greater value), constant throughout the increment, the mechanism should allow an increment to be applied within 2 s (recommendation), stable (e.g. bolted to the floor) and free of vibration; balance 0,01 g or 0,1 %, timer 1 s, maximum/minimum thermometer 1 °C, metal disc about 1 mm smaller than the ring and of the same height, callipers 0,05 mm; water of a chemistry similar to the pore water if the soil is susceptible to water chemistry — if unknown, tap water, because its chemistry is more likely to be similar to ground water than distilled water. Procedure (6): mean diameter of the largest particle less than one fifth of the ring height; initial water content w₀ from trimmings according to ISO 17892-1; specimens are trimmed from an undisturbed sample (extruded from a tube or block), extruded directly from a tube of larger diameter, or recompacted, remoulded or reconstituted; the cutting edge is checked before each use; a horizontal flat surface larger than the ring is prepared on the sample, and the ring is centred unless discontinuities or disturbance suggest a better position off-centre. From the table of contents: assembly of the cell and in the load frame, loading sequence and application of loads, dismantling, initial values (water content, density), specimen height, vertical strain, void ratio, compression–stress diagram, mandatory and optional reporting, Annex B with additional calculations.

STATUS (PKN catalogue cards as of 02.10.2026). The card of PN-EN ISO 17892-5:2017-06 (Polish version, published 30-08-2022, 32 pages, price group P) has no “Withdrawn” header: Building and Construction Sector, KT 254 Geotechnics, ICS 13.080.20 and 93.020, “Introduces: EN ISO 17892-5:2017 [IDT], ISO 17892-5:2017 [IDT]”. The PKN search for “PN-EN ISO 17892-5” (02.10.2026) shows the English and Polish versions 2017-06. The EVS catalogue (read 02.10.2026) lists ISO 17892-5:2017 as valid from 03.03.2017.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, data up to 17.09.2026, read 02.10.2026). The number 17892-5 appears in 8 records at 6 laboratories: AB 283, AB 962, AB 1770, AB 1778, AB 1806, AB 1914. In the current scopes on the PCA website (read 02.10.2026, issues from 24.09.2024 to 17.07.2026) all give “PN-EN ISO 17892-5:2017-06”; AB 1778 also lists the specification PKN-CEN ISO/TS 17892-5:2009, and AB 962 has a separate entry “Swelling pressure” citing ONLY that specification. The “Laboratories” tab searches for entries STARTING WITH “PN-EN ISO 17892-5” and shows all 6 laboratories — checked with the tab query on the production server labcoda.pl on 02.10.2026.

WHAT THE LABORATORIES TEST (PCA entries). Soils — “Oedometer test of soils” in a load range from 0 to 6400 kPa (AB 962) and from 0 to 550 kPa (AB 1806); “Oedometer modulus determined in the oedometer” from 0 to 1600 kPa (AB 1778); “Primary and secondary compressibility modulus of soil, oedometer method” (AB 283); “Compressibility and consolidation of soil” from 0 to 32 000 kPa (AB 1914); soils, marine sediments, building materials — “Compressibility and consolidation characteristics of soil” from 0 to 25 MPa, “incremental loading oedometer test method” (AB 1770, two entries).

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Specimen: the largest particle must be smaller than one fifth of the ring height, and a small specimen usually does not represent the structure of natural soil. Ring and discs: the ring may not expand by more than 0,05 %, discs must be of negligible compressibility, new ones boiled, used ones cleaned and checked that the pores are not clogged, because the permeability of the discs (and any filter paper) must not retard the drainage of the specimen (5.2); for stiff clays discs are air-dried before use. Water: distilled water instead of water similar to the pore water may change the behaviour of a soil susceptible to water chemistry — the standard then recommends tap water. Loading: an increment is held to 1 % or 1 kPa (requirement), and the mechanism should allow it to be applied within 2 s (recommendation); the frame must be stable when fully loaded and free of vibration (5.6). Interpretation: in foundations stress paths and drainage are three-dimensional, so the magnitude and rate of settlement calculated from the oedometer may differ from actual ones; for unsaturated soils some parameters may be inappropriate. Name of the quantity: laboratories give “oedometer modulus”, “primary and secondary compressibility modulus” or “compressibility and consolidation characteristics” — the part of the standard we read defines vertical strain, void ratio and the compression–stress diagram, and the formulae for moduli are in Clause 7 and Annex B, which we do not have. Specification: swelling pressure at AB 962 is based on the withdrawn 2009 technical specification, not on this standard.

WHAT WE DO NOT STATE. We do not have 6.2.2.3–6.6 or Clauses 7–8 and Annexes A and B: the sequence and size of load increments, duration of an increment, criteria for end of consolidation, formulae for height, strain, void ratio, moduli and coefficient of consolidation, content of the test report — we therefore give none of these figures or formulae.

Method principle

A cylindrical soil specimen in a rigid ring, drained through porous discs at top and bottom, is loaded (and unloaded) vertically in successive increments (the mechanism should allow an increment to be applied within 2 s), and the settlement is measured over time; vertical strain, void ratio and the compression–stress diagram are determined from the specimen height at the end of each increment.

Applications

• Cohesive and organic soils in geotechnical investigation — compressibility, consolidation, oedometer modulus; 6 laboratories in PCA scopes
• Prediction of foundation settlement (design according to EN 1997-1 and EN 1997-2)
• Marine sediments and building materials tested in the oedometer (scope of one laboratory)

Key parameters

Standard

Standard number

PN-EN ISO 17892-5:2017-06 (wersja polska; EN ISO 17892-5:2017 IDT, ISO 17892-5:2017 IDT)

Title (PL)

Rozpoznanie i badania geotechniczne — Badania laboratoryjne gruntów — Część 5: Badanie edometryczne gruntów

Title (EN)

Geotechnical investigation and testing — Laboratory testing of soil — Part 5: Incremental loading oedometer test

Step-by-step procedure

1. Preparation

   Discs boiled or cleaned; check the edge of the ring; largest particle < 1/5 of the ring height. PN-EN ISO 17892-5:2017-06 current (PKN cards as of 02.10.2026).

2. Specimen

   Trimming from an undisturbed sample, extrusion from a tube or recompaction/reconstitution; ring centred on a flat surface; w₀ from trimmings according to ISO 17892-1.

3. Assembly

   Ring with specimen between discs in the cell, loading cap, frame; flooding with water — according to 6.4 (outside the part we read).

4. Loading

   Successive increments (the mechanism should allow an increment to be applied within 2 s), constant during the increment (1 % or 1 kPa); settlement measured over time; unloading according to the programme (6.5).

5. Results

   Height, vertical strain, void ratio and compression–stress diagram according to Clause 7 (we do not have the formulae); test report according to Clause 8.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The standard contains no safety warnings in the part we read; the loading frame must be stable when fully loaded, e.g. bolted to the floor (5.6)
• TECHNICAL NOTE: oedometer results concern one-dimensional deformation of a small saturated specimen; stress paths in foundations are three-dimensional

Frequently asked questions