Overview
ISO 22476-12:2009 - Geotechnical investigation and testing - Part 12: Mechanical cone penetration test (CPTM) - defines requirements for performing mechanical cone penetration tests (CPTM). The standard covers equipment, execution and reporting for CPTM, a constant‑rate pushing test that records cone penetration resistance and, where applicable, sleeve friction and total penetration force. CPTM results are used for soil profiling, classification and estimation of geotechnical parameters such as density, shear strength and deformation/consolidation behaviour.
Keywords: ISO 22476-12, CPTM, mechanical cone penetration test, cone penetration test, geotechnical investigation, in situ testing
Key topics and technical requirements
- Scope and purpose: Specifies CPTM types, application classes and essential test features (penetration length/depth, ground elevation relative to datum, test location referencing).
- Equipment: Defines components and measurement systems including cone, friction sleeve, inner rods, push rods, thrust machine, load sensors/manometers and friction reducers.
- Measurement parameters: Addresses measured variables such as cone penetration resistance (qc), sleeve friction (fs), total penetration force (Qt), penetration length/penetration depth, and phenomena like zero drift.
- Test procedures: Distinguishes continuous vs discontinuous penetration testing, requirements for pushing at a constant rate, use of friction reducers, logging frequency, and procedures for measuring cone and sleeve forces.
- Quality and calibration: Includes tolerances, surface roughness considerations, equipment checks and calibration requirements (maintenance and calibration guidance in normative annex).
- Reporting: Specifies mandatory report items (type of CPT, application class, penetration metrics, elevation and location relative to a reproducible datum, measured and calculated parameters, presentation of results).
SEO keywords integrated: sleeve friction, cone resistance, push rods, thrust machine, measuring system, penetration depth.
Practical applications and users
- Applications:
- Soil stratification and profiling for site investigation
- Classification of soil type and relative comparison with other in‑situ tests
- Estimation of geotechnical parameters (density, shear‑strength, deformation/consolidation) to support foundation design, ground improvement and earthworks
- Baseline data for geotechnical modelling and risk assessments
- Who uses it:
- Geotechnical engineers and consultants
- Field testing contractors and drilling/pushing crews
- Civil and structural engineers using subsurface data for design
- Laboratories and researchers validating CPT procedures and equipment
Related standards
- ISO 22476 series (other field testing parts: SPT, dynamic probing, dilatometers, pressuremeter, etc.)
- Normative references cited: ISO 8503 (surface roughness) and ISO 10012 (measurement management)
- Guidance for applying investigation results in design: EN 1997‑1 / EN 1997‑2 (Eurocode 7)
ISO 22476-12:2009 is the reference standard for reliably executing and reporting mechanical CPT tests and producing consistent, comparable in‑situ geotechnical data.
Open preview (PDF)Geotechnical investigation and testing — Field testing — Part 12: Mechanical cone penetration test (CPTM)