ISO 22476-1:2022

Overview

ISO 22476-1:2022 - "Geotechnical investigation and testing - Field testing - Part 1: Electrical cone and piezocone penetration test" defines equipment, procedural and reporting requirements for electronic cone penetration tests (CPT) and piezocone tests (CPTU). The standard covers onshore and nearshore investigations, specifying required test features such as cone penetrometer class, test category, penetration length/depth, site elevation and location references, and pore pressure dissipation tests (PPDT). It applies to electronic transducer systems; mechanical CPT practice is covered in ISO 22476-12. For offshore CPT requirements see ISO 19901-8.

Key topics and technical requirements

• Equipment requirements: cone penetrometer, friction sleeve, filter element for pore-pressure measurement, pushrods, thrust machine and measuring system (sensors for cone resistance, sleeve friction, pore pressure, inclination and temperature).
• Penetrometer classification and test categories: the standard requires reporting of cone penetrometer class (see Table 2) and test category (see Table 3) to document suitability and accuracy.
• Calibration and verification: provisions for calibration, checks and conformity assessment of penetrometers and measuring systems are included to ensure data reliability.
• Test procedures: procedures for positioning the thrust machine, preparing and pushing the cone at constant rate, data recording frequency, registration of penetration length, and use of friction-reduction techniques.
• Pore pressure and PPDT: guidance on measuring pore pressures during CPTU and conducting pore pressure dissipation tests to obtain consolidation and hydraulic information.
• Data handling and reporting: required measured and calculated parameters, corrections, presentation and minimum reporting content (location, elevation, equipment, raw and processed data).
• Quality, safety and maintenance: requirements for equipment tolerances, maintenance, environmental/temperature considerations (including internal temperature monitoring for certain classes), and safety measures.

Practical applications and users

ISO 22476-1:2022 is used for geotechnical site characterization and provides data for:

• Stratification and soil behaviour type profiling
• Estimating geotechnical parameters: density, shear strength, deformation/consolidation properties, hydraulic conductivity and groundwater pressures
• Foundation design, earthworks, slope stability, liquefaction assessment and construction risk management

Primary users:

• Geotechnical engineers and site investigation consultants
• Field technicians and CPT service providers
• Manufacturers of cone penetrometers and instrumentation
• Laboratories interpreting CPT/CPTU data and clients requiring contractual test reporting
• Regulators and designers applying EN 1997 (Eurocode 7) requirements

Related standards

• ISO 22476-12 (mechanical CPT practice)
• ISO 22475-1 (sampling) and ISO 14688-1 (soil identification)
• EN 1997 series (Eurocode 7) - geotechnical design
• ISO 19901-8 (offshore CPT requirements)

Keywords: ISO 22476-1:2022, cone penetration test, piezocone, CPT, CPTU, geotechnical investigation, pore pressure, penetrometer class, test reporting, field testing.