SIST EN ISO 18674-4:2020 PDF

Overview

EN ISO 18674-4:2020 (CEN) - Geotechnical investigation and testing - Geotechnical monitoring by field instrumentation - Part 4: Measurement of pore water pressure: Piezometers - specifies methods for measuring pore water pressures and piezometric levels in saturated ground using piezometers installed for geotechnical monitoring. It is part of the ISO 18674 series and links to general monitoring rules in ISO 18674‑1. When applied with ISO 18674‑5, it supports determining effective stresses acting in the ground.

Key topics and requirements

• Scope and applicability: Measurement of pore water pressure in saturated soils for geotechnical structures, fills and works (quay walls, dikes, foundations, tunnels, dams, slopes, embankments, etc.).
• Instrument types: Classification and guidance for open and closed piezometer systems, including system selection and component requirements.
• Measurement principles: Distinction between absolute and relative measurements and requirements for atmospheric compensation.
• Filters and response: Requirements for piezometer filters and consideration of response time (see Annex D) to ensure representative pore pressure readings.
• Measuring range and accuracy: Specification of measurement performance expectations appropriate for geotechnical monitoring.
• Installation and procedure: Detailed guidance on installation methods for different piezometer types, pre‑ and post‑installation checks, maintenance and protective measures (Annex C).
• Data handling: Procedures for carrying out measurements, instrument calibration, data processing, evaluation and interpretation.
• Reporting: Required contents for installation and monitoring reports (installation report, monitoring report).
• Normative and informative annexes: Practical procedures (Annex A), geo‑engineering applications (Annex B), fully grouted installations (Annex E) and measurement of soil suction (Annex F).

Applications and users

EN ISO 18674‑4:2020 is used to plan, install, operate and interpret piezometric monitoring for:

• Monitoring water pressures acting on/in geotechnical structures (dams, quay walls, excavation walls, retaining structures)
• Monitoring consolidation under foundations and embankments
• Evaluating stability and serviceability of slopes, tunnels and earthworks
• Verifying geotechnical designs within an Observational Design framework

Typical users:

• Geotechnical and civil engineers
• Site instrumentation contractors
• Geotechnical consultants and survey teams
• Infrastructure owners, dam safety authorities and regulatory bodies

Related standards

• ISO 18674‑1: General rules for geotechnical monitoring
• ISO 18674‑5: Measurement of water pressures in relation to effective stress determination
• ISO 22476‑1: Pore pressure measurements associated with cone penetration testing

This standard is essential for accurate, reliable pore water pressure monitoring using piezometers, improving safety and performance assessment of geotechnical works.