Overview
EN ISO 22476-6:2018 - "Geotechnical investigation and testing - Field testing - Part 6: Self boring pressuremeter test" - specifies equipment, execution and reporting for the self-boring pressuremeter (SBP) test. The standard covers in situ measurement of soil and weak rock deformation by the controlled expansion and contraction of a cylindrical flexible membrane. EN ISO 22476-6:2018 also fulfils SBP requirements for geotechnical investigations under EN 1997-1 and EN 1997-2.
Key topics and requirements
- Scope and definitions: clear terminology for SBP, pressuremeter, self-boring head, sounding and test depth.
- Equipment requirements: composition of an SBP system - self-boring head, pressuremeter probe, hydraulic pump or pressure source, Control Unit (CU), data logger, pressure/displacement lines and connections.
- Probe placement and drilling: use of the self-boring head to create a test pocket while minimising disturbance to surrounding soil.
- Calibration and corrections: procedures for device calibration and correction of readings (normative Annex A) to ensure reliable displacement and pressure data.
- Test procedure and loading program: steps for selection of equipment, probe insertion, relaxation, staged loading/unloading, and defined end-of-test criteria (Clause 6).
- Measurement and data acquisition: requirements for pressure and displacement measurement, display and recording (data acquisition and CU requirements).
- Result interpretation and reporting: required content of SBP test reports and guidance for interpreting pressure versus displacement curves.
- Accuracy and conversions: guidance on measurement accuracy (Annex C) and strain/displacement conversions (Annex D).
- Normative references: links to ISO 10012 (measurement management) and ISO 22475-1 (sampling and groundwater measurement principles).
Applications
- In situ determination of soil and weak rock deformation properties for:
- Foundation design (shallow and deep foundations)
- Earthworks, retaining structures and slope stability assessments
- Underground works and tunnelling ground characterization
- Ground improvement and anchor design verification
- Useful where minimal disturbance of the test zone is required and where pressuremeter curves inform stiffness, limit pressures and deformation modulus.
Who should use this standard
- Geotechnical engineers and consultants performing site investigations
- Field testing contractors and drilling/boring operators using self-boring pressuremeters
- Structural and foundation designers referencing EN 1997 compliance
- Laboratories and QA/QC personnel responsible for calibration, data acquisition and test reporting
Related standards
- EN 1997-1 / EN 1997-2 (Eurocode 7 geotechnical design and investigation)
- ISO 22475-1 (sampling and groundwater measurement)
- ISO 10012 (measurement management systems)
EN ISO 22476-6:2018 is essential for consistent, reliable SBP field testing and for integrating pressuremeter data into geotechnical design and site investigation workflows.
