SIST EN ISO 18674-5:2019 PDF

Overview

SIST EN ISO 18674-5:2019 specifies the methodology for measuring stress changes in soils, ground structures, and interfaces using total pressure cells (TPC). Developed by CEN and aligned with international ISO standards, this standard is crucial for geotechnical investigation and testing, especially in projects involving earthworks, underground works, and foundation construction. The document provides requirements and guidelines necessary for effective geotechnical monitoring using field instrumentation, supporting safety, design validation, and performance monitoring as outlined in related standards such as EN 1997-1 and EN 1997-2.

Key Topics

• Measurement of Stress Change: Defines how to use total pressure cells to monitor stress variations in soils and geo-engineered structures.
• Types of Installations: Covers embedment in fill, ground installations, borehole applications, and interface measurement (e.g., at foundation bases or retaining walls).
• Instrument Features:
  • Principal components: pressure compartment, tubing, measuring device, and control units.
  • Emphasizes proper selection and installation to reduce measurement errors, account for stress concentrations, and improve reliability.
• Monitoring Applications: Addresses both short-term and long-term monitoring requirements for construction and operational stages.
• Observational Design Integration: Supports the iterative design and construction process by providing real-time data for design checks and adjustments.
• Stability Assessment: Enables ongoing evaluation of structural and ground stability for improved safety and risk management.

Applications

SIST EN ISO 18674-5:2019 is widely applied in the geotechnical field for:

• Earth Dams and Embankments: Measuring stress distribution within the dam body, core, and interfaces to prevent failures and optimize design.
• Tunnel and Underground Construction: Monitoring radial and tangential stresses on tunnel linings and surrounding ground to detect potential instability or excessive load.
• Foundation Engineering: Measuring contact pressure at the base of raft and slab foundations to validate design assumptions and prevent overload.
• Retaining Wall Systems: Assessing earth pressures acting on retaining walls, ensuring wall stability and detecting unexpected load transfer.
• Performance Monitoring of Geotechnical Works: Supporting quality assurance and validation of construction against design intent.
• Instrumented Observational Design: Enabling contractors and engineers to modify work practices and designs dynamically in response to measured field data.

Related Standards

The application of SIST EN ISO 18674-5:2019 is often complemented by other standards, ensuring holistic and compliant geotechnical monitoring:

• EN ISO 18674-1: General rules for geotechnical monitoring by field instrumentation.
• EN ISO 18674-4: Measurement of pore water pressure with piezometers - crucial for effective stress determination when paired with TPC measurements.
• EN 1997-1 (Eurocode 7): General rules and requirements for geotechnical design.
• EN 1997-2 (Eurocode 7-2): Geotechnical investigation and testing.
• ISO 22475-1: Standards for sampling methods and groundwater measurements, relevant to site investigations for TPC installation.

Practical Value

Adhering to SIST EN ISO 18674-5:2019 delivers significant benefits:

• Safety: Early detection of adverse stress changes prevents failures and incidents during and after construction.
• Design Assurance: Real-time monitoring validates and informs design adjustments, supporting the Observational Design process.
• Regulatory Compliance: Fulfils European and international requirements for geotechnical monitoring and reporting.
• Adaptability: Facilitates proactive management of complex ground-structure interactions in challenging conditions.

By standardizing the use of total pressure cells for stress change measurement, this document ensures accuracy, reliability, and comparability of geotechnical monitoring data across a wide range of civil engineering projects.