Overview
EN ISO 22476-8:2018 - Geotechnical investigation and testing - Field testing - Part 8: Full displacement pressuremeter test (FDP) - specifies equipment requirements, execution and reporting for full displacement pressuremeter tests. The standard defines how to measure in situ deformation of soils and weak rocks by expansion and contraction of a cylindrical flexible membrane mounted on a probe. EN ISO 22476-8:2018 also fulfils FDP test requirements for geotechnical investigation services referenced in EN 1997-1 and EN 1997-2.
Key topics and technical requirements
- Scope and intent: Defines the FDP assembly (pressuremeter module + cone module) and limits of use - the FDP is jacked or driven directly into undisturbed ground and creates its own test cavity (no pre-boring or pre-pushing).
- Equipment specification: Requirements for the pressuremeter module, cone module, membrane, push rod connection and measuring systems. Differentiates volume-displacement and radial-displacement pressuremeters.
- Performance characteristics: Concepts specified include membrane length, membrane pressure loss, membrane compressibility, and system compliance - factors required for correct calibration and interpretation.
- Test procedure: Guidance on selection of equipment, site preparation, installation, staged pressure testing (including optional stages), logging frequency, test completion, and handling of test data.
- Calibration and corrections: Normative annexes address calibrations, corrections to measured volume and pressure, and procedures to account for system compliance and membrane behaviour.
- Reporting and uncertainty: Required content for test reports and informative annex on measurement uncertainties, plus normative references for measurement management (e.g., ISO 10012).
Practical applications and users
Who uses EN ISO 22476-8:2018:
- Geotechnical engineers, site investigation teams and geotechnical consultants
- Foundation and geotechnical design offices (foundation design, retaining structures)
- Contractors conducting in situ testing and geotechnical laboratories
- Regulators and standards bodies enforcing compliant site investigation practice
Typical applications:
- Determining in situ stress–strain response of soils and weak rocks
- Estimating deformability and modulus parameters for foundation and pile design
- Assessing lateral earth pressures and settlement behaviour
- Characterising ground for excavation support and underground works
Related standards
- ISO 22476-1 (Electrical cone and piezocone penetration test)
- ISO 22476-4:2012 (Ménard pressuremeter test)
- ISO 10012 (Measurement management systems)
- EN 1997-1 / EN 1997-2 (Eurocode 7 geotechnical design / investigations)
EN ISO 22476-8:2018 is essential for consistent, reliable pressuremeter testing and reporting in modern geotechnical site investigations. Keywords: EN ISO 22476-8:2018, full displacement pressuremeter, FDP test, pressuremeter testing, geotechnical investigation, in situ soil testing, pressuremeter equipment, field testing.
