🏗️ Coefficient of permeability k of soil (ratio of discharge velocity to hydraulic gradient, Darcy’s law for laminar flow in saturated soil) on a cylindrical specimen in a rigid wall permeameter (cylindrical or oedometer ring) or a flexible wall permeameter (membrane in a triaxial cell), under constant or falling head or constant flow, with correction for water temperature, PN-EN ISO 17892-11

Construction PN-EN ISO 17892-11

Overview

WHAT THE STANDARD COVERS. Scope from the PKN catalogue card of PN-EN ISO 17892-11:2019-05, in full (our translation of the Polish card text): “This document describes methods for the laboratory determination of the water flow characteristics of soil. This document is applicable to the laboratory determination of the coefficient of permeability of soil within the scope of geotechnical investigation. NOTE: This document fulfils the requirements for the laboratory determination of the coefficient of permeability of soils in geotechnical investigation and testing in accordance with EN 1997-1 and EN 1997-2”. We read the text of the standard in the preview of ISO 17892-11:2019 from the cover to clause 5.2.3.1 (flexible wall permeameter — general, page 5); we do not have the further clauses of Clause 5 (porous discs, permeant water properties, measuring devices), Clauses 6–8 (procedure, results with temperature correction, test report) or the normative Annex A (calibration and checks).

ACCORDING TO THE TEXT OF ISO 17892-11:2019 (foreword, introduction, Clauses 1–5.2.3.1). The standard was prepared by CEN/TC 341 (geotechnical investigation and testing) in collaboration with ISO/TC 182 (geotechnics) under the Vienna Agreement. The first edition replaces the specification ISO/TS 17892-11:2004 and incorporates its corrigendum Cor 1:2006; changes: new structure, revision of text and figures, added specimen preparation procedures; rigid wall permeameters — cylindrical and oedometer ring — and flexible wall permeameters are included; measurement at constant head, falling head and constant flow was added; a normative Annex A on calibration, maintenance and checks was added. Introduction: the test is carried out on a cylindrical specimen confined laterally by a rigid container or a flexible membrane; the specimen is subjected to a differential head and the flow is measured under constant or falling head; undisturbed, remoulded, compacted or reconstituted specimens may be tested; the calculation assumes Darcy’s law for laminar flow under fully saturated conditions; the specimen size may not represent the fabric features present in the field. Scope (Clause 1): methods for the laboratory determination of water flow characteristics of soil and of the coefficient of permeability in geotechnical investigation (note on EN 1997-1 and EN 1997-2). Normative references: ISO 386 (liquid-in-glass thermometers), ISO 14688-1 (identification and description of soil), ISO 17892-1 (water content), ISO 17892-2 (bulk density), ISO 17892-3 (particle density). Definitions (Clause 3): permeameter — apparatus (cell) containing the specimen; flow rate — volume of water passing through the specimen per unit time; discharge velocity — flow rate per unit cross-sectional area in the direction of flow; hydraulic gradient — ratio of the difference in head (head loss) between two points to the length of the flow path, i = Δh/l; coefficient of permeability — ratio of discharge velocity to hydraulic gradient, in accordance with Darcy’s law for laminar flow; degree of saturation — ratio of the volume of water to the volume of voids. Symbols (Clause 4): among others A — cross-sectional area of the specimen, a — cross-sectional area of the standpipe, B — pore pressure coefficient, Δh — difference in head, l — distance between measuring points, k and kT — coefficient of permeability and coefficient corrected to temperature, α — temperature correction factor. Apparatus (5.1–5.2.3.1): regular calibration, maintenance and checks according to Annex A; the minimum internal dimension of the permeameter (height and diameter) at least six times the maximum particle size of the specimen; rigid wall permeameters — of corrosion-resistant materials of sufficient rigidity, inlets and outlets of a capacity that does not influence the result; the inside may be coated with a hydrophobic coating (silicone grease, petroleum jelly with bentonite) against flow along the wall; cylindrical permeameter — a mould with porous discs on the top plate and base plate, watertight valves, possibly standpipe glands along the cylinder and a lockable piston maintaining the specimen height (Figure 2 — constant head test); oedometer ring permeameter — the ring of an oedometer for compression tests (Figure 3 — falling head test); flexible wall permeameter — when the specimen is tested under specific effective stress or with back pressure to full saturation; it may be a standard triaxial apparatus with a pressure cell, base pedestal and top cap with porous discs, connections to the flow measurement system and a membrane sealing the specimen surface — this is where the part we read ends.

STATUS (cards as of 02.10.2026). The cards of PN-EN ISO 17892-11:2019-05 in the English version (published 08-05-2019, 34 pages, price group Q) and the Polish version (published 12-11-2021, 28 pages, price group N) do not carry the heading “Wycofana” (withdrawn): Building and Construction Sector, KT 254 Geotechnics, ICS 13.080.20, 93.020, “Introduces: EN ISO 17892-11:2019 [IDT], ISO 17892-11:2019 [IDT]”. The card of PKN-CEN ISO/TS 17892-11:2009 (Polish version, published 11-08-2009, “Permeability test with constant and falling hydraulic gradient”, introduced CEN ISO/TS 17892-11:2004 with AC:2005) does not carry the heading “Wycofana”, but its table states “Date of withdrawal: 18-04-2019”.

HOW MANY LABORATORIES AND IN WHAT FORM (copy of the accreditation scope database, load up to 17.09.2026, read on 02.10.2026). The number 17892-11 appears in 10 records at 10 laboratories: AB 005, AB 106, AB 213, AB 283, AB 300, AB 313, AB 418, AB 1059, AB 1416, AB 1806. In the current scopes on the PCA website (read on 02.10.2026, issues from 01.10.2025 to 08.09.2026): only PN-EN ISO 17892-11:2019-05 — AB 005 (“excluding cl. 5.2.2.2 and cl. 5.2.3”, i.e. only the oedometer ring), AB 106, AB 1806; both forms — the withdrawn 2009 specification and the 2019 standard — AB 283, AB 313 (entry “PN-CEN ISO/TS”) and AB 418 (specification “excluding cl. 4.4”, standard “excluding cl. 5.2.3”); only the withdrawn PKN-CEN ISO/TS 17892-11:2009 — AB 213, AB 300, AB 1059 (“cl. 4.2”) and AB 1416 (“cl. 4.2”). No row is set in bold italics. The “Laboratories” tab searches for entries STARTING WITH the entered number: “PN-EN ISO 17892-11” shows 6 laboratories and 6 items (AB 005, AB 106, AB 283, AB 313, AB 418, AB 1806), “PKN-CEN ISO/TS 17892-11” — 5 laboratories and 5 items (AB 213, AB 283, AB 300, AB 418, AB 1059) — checked with the tab query on the labcoda.pl production server on 02.10.2026; AB 1416 is not visible, because its entry in the database is split into two fields.

WHAT THE LABORATORIES TEST (items in the PCA scopes). Soils and grounds — “permeability — coefficient of permeability, hydraulic gradient method”, with ranges among others (1,0·10⁻⁹–1,0·10⁻⁴) m/s (AB 106), (1,0·10⁻⁸–1,0·10⁻⁵) m/s (AB 213), (1,0·10⁻⁹–1,0·10⁻³) m/s (AB 300, AB 418), (1,0·10⁻¹⁰–1,0·10⁻⁵) m/s (AB 313), (10⁻¹⁰–10⁻⁶) m/s (AB 1059), (1·10⁻⁵–1·10⁻¹⁰) m/s (AB 005); “coefficient of permeability”, (1·10⁻⁶–1·10⁻¹¹) m/s, in a flexible wall permeameter (AB 283); “coefficient of permeability in an oedometer ring” (AB 1806); “permeability under constant and falling hydraulic gradient” (AB 1416). Alongside particle size distribution (PN-EN ISO 17892-4), water content, oedometer tests and coefficient of permeability from empirical formulae according to in-house procedures.

WHERE A SEEMINGLY CORRECT RESULT IS EASY TO GET. Saturation: Darcy’s law requires full saturation and laminar flow — a specimen with air in the pores gives a low k; therefore for cohesive soils a flexible wall permeameter with back pressure is used. Wall: in a rigid permeameter water flows through a gap along the wall and increases k — the standard allows a hydrophobic coating; in swelling and shrinking soils the problem is greatest. Dimensions: a permeameter smaller than six times the largest particle gives an unrepresentative result; a small specimen may not represent fissures and layering in the field. Temperature: water viscosity changes with temperature — a result without correction to the reference temperature (kT) is not comparable (method of correction in 7.3, NOT GIVEN). Apparatus: too small inlets and outlets restrict flow and lower k in permeable soils. Reference: the specification PKN-CEN ISO/TS 17892-11:2009 has been withdrawn since 18-04-2019, and four laboratories cite only it; in the 2019 standard Clause 4 is symbols (without clauses 4.2 and 4.4), so exclusions recorded with the 2009 specification (e.g. “cl. 4.2”, “cl. 4.4”) cannot be transferred to the standard directly; we have not read the text of the specification.

WHAT WE DO NOT GIVE. We do not have clauses 5.3–5.6 (porous discs, water properties, measuring devices), Clause 6 (saturation, choice of gradient, water temperature, specimen preparation, flow measurement), Clause 7 (formulae for k under constant and falling head, temperature correction), Clause 8 (test report) or Annex A — so we do not give formulae, permissible gradients or the reference temperature.

Method principle

A cylindrical, water-saturated soil specimen in a rigid or flexible wall permeameter is subjected to a differential head and the volume of water flowing over time is measured — under constant head, falling head or constant flow; the coefficient of permeability is the ratio of discharge velocity to the hydraulic gradient i = Δh/l (Darcy’s law), corrected to a reference temperature.

Applications

• Soils and grounds in geotechnical investigation (EN 1997-1 and EN 1997-2) — coefficient of permeability, 10 laboratories
• Mineral barriers, seals and embankments — compacted and reconstituted soils, tested under specific effective stress
• Undisturbed, remoulded, compacted or reconstituted specimens; testing in the oedometer together with compressibility

Key parameters

Standard

Standard number

PN-EN ISO 17892-11:2019-05 (wersje angielska i polska; EN ISO 17892-11:2019 IDT, ISO 17892-11:2019 IDT)

Title (PL)

Rozpoznanie i badania geotechniczne — Badania laboratoryjne gruntów — Część 11: Badania filtracji

Title (EN)

Geotechnical investigation and testing — Laboratory testing of soil — Part 11: Permeability tests

Step-by-step procedure

1. Choice of permeameter

   Rigid (cylinder or oedometer ring) or flexible (triaxial apparatus) according to the soil and purpose; interior ≥ 6 × the largest particle. PN-EN ISO 17892-11:2019-05 current (cards as of 02.10.2026).

2. Specimen preparation

   Undisturbed, remoulded, compacted or reconstituted specimen; water content, bulk density and particle density according to ISO 17892-1, -2 and -3 (details of preparation — 6.2, NOT GIVEN).

3. Saturation

   Full saturation of the specimen — in a flexible permeameter with back pressure (6.1.1, criteria NOT GIVEN).

4. Flow measurement

   Constant head, falling head or constant flow; readings of head, volume and time and of water temperature (6.4, details NOT GIVEN).

5. Result

   Coefficient of permeability k from Darcy’s law, corrected to the reference temperature (kT); formulae and report — Clauses 7 and 8 (NOT GIVEN).

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• The triaxial apparatus operates under pressure — check the tightness of the cell and the safety valves; soil samples from contaminated sites to be treated as potentially hazardous material; the part of the standard we read contains no safety warnings
• SUBSTANTIVE NOTE: k depends on saturation, flow along the wall and water temperature; four laboratories cite only the withdrawn specification PKN-CEN ISO/TS 17892-11:2009, whose exclusions (cl. 4.2, 4.4) have no counterpart in the 2019 standard, where Clause 4 is symbols

Frequently asked questions