EN ISO 18674-3:2017 PDF

Overview

EN ISO 18674-3:2017 - "Geotechnical investigation and testing - Geotechnical monitoring by field instrumentation - Part 3: Measurement of displacements across a line: Inclinometers" (CEN adoption of ISO 18674‑3:2017) specifies procedures for measuring displacements across a line using inclinometers as part of geotechnical monitoring. It defines system components, installation and measurement procedures, data processing, evaluation and reporting requirements to support performance monitoring of ground, geotechnical fills and structures interacting with the ground.

Key topics and technical requirements

• Scope and limitations
  • Measurement of displacements across a measuring line by means of inclinometers.
  • For vertical measuring lines, inclinometers determine both horizontal displacement components; for horizontal lines, inclinometers determine the vertical component only.
  • Deflectometers (Annex B) are referenced to supplement inclinometers for horizontal-line horizontal displacements.
• Instruments and components
  • Probe inclinometers (traversing probes) and in‑place inclinometers (IPI).
  • Guide tubes/casings, tilt sensors, position measurement and read-out devices.
• Installation and field procedures
  • Borehole drilling and guide tube installation, securing measurement locations, and installation in concrete or accessible surfaces.
  • Specific guidance on in‑place inclinometer installation.
• Measurement quality
  • Requirements for measuring range, accuracy, repeatability, instrument checks and calibration prior to data acquisition.
• Data handling
  • Processing and evaluation of inclination data to compute displacements; reporting formats for installation and monitoring results.
• Supporting material
  • Normative measuring procedures (Annex A), deflectometer details (Annex B), recommended backfill materials (Annex C), applications and examples (Annexes D and E).

Practical applications

EN ISO 18674‑3:2017 is applicable to:

• Checking geotechnical designs using the Observational Design procedure.
• Monitoring slopes, embankments, excavation walls, foundations, dams, tunnels, refuse dumps before, during and after construction.
• Deriving geotechnical key parameters (e.g., from pile load tests or trial tunnelling).
• Identifying and monitoring active shear planes in the ground.

Who should use this standard

• Geotechnical engineers and consultants performing site monitoring and instrumented investigations.
• Contractors and site supervisors responsible for inclinometer installation and data collection.
• Instrument manufacturers and calibration laboratories developing inclinometer systems and quality procedures.
• Project owners and safety assessors requiring standardized monitoring data for design verification and risk management.

Related standards

• ISO 18674‑1:2015 - General rules for geotechnical monitoring by field instrumentation.
• ISO 18674‑2:2016 - Measurement of displacements along a line: extensometers.
• ISO 22475‑1:2006 - Sampling and groundwater measurement technical principles.

Keywords: EN ISO 18674-3:2017, inclinometer, geotechnical monitoring, displacement measurement, deflectometer, probe inclinometer, in‑place inclinometer, borehole monitoring, observational design, monitoring report.