ISO 22477-6:2026 PDF

Overview

ISO 22477-6:2026 is an international standard developed by ISO focused on geotechnical investigation and testing, specifically for load testing of soil nails and rock bolts. Together referred to as "elements" in this standard, soil nails and rock bolts are structural reinforcements commonly used in geotechnical engineering for stabilizing earth retention systems and slopes. This document specifies the procedures, equipment, and requirements for tension tests, including investigation, suitability, and acceptance tests, applicable to both grouted and non-grouted elements. The standard is essential for ensuring that geotechnical structures meet safety, performance, and design criteria, supporting reliable and comparable load testing across different projects and locations.

Key Topics

• Test Types: The standard describes three main types of tension testing for soil nails and rock bolts:

  • Investigation tests - to determine ultimate geotechnical resistance and behavior under working loads.
  • Suitability tests - to confirm the adequacy of a particular design in specific ground conditions.
  • Acceptance tests - to verify compliance of installed elements with project requirements.

• Testing Methods:

  • Test Method A: Step-loaded maintained load tension tests, where load is increased incrementally and held constant at each step.
  • Test Method B: Constant displacement rate tension tests, typically involving a steady rate of movement applied to the element head.

• Equipment Specifications:

  • Requirements for loading devices, reaction systems, load and displacement measurement, and calibration in accordance with ISO 7500-1.
  • Specification of minimum uncertainties for load and displacement measurements.

• Results and Reporting:

  • Procedures for data collection, interpretation, and reporting, including both raw data and interpretative analysis.
  • Plots and records must detail applied loads, displacements, and derived pull-out resistance values.

• Scope Limitation: The standard does not determine the number or type of tests, proof load values, or limiting criteria, which should be referenced in EN 1997-3 and national annexes or similar standards.

Applications

Implementing ISO 22477-6:2026 ensures:

• Consistent and traceable testing procedures for load testing of soil nails and rock bolts, which contributes to:

  • The assessment of load-bearing capacity and pull-out resistance.
  • Confirmation that reinforcing elements behave as intended in site-specific geotechnical conditions.
  • The safety and performance validation of geotechnical structures, such as retaining walls, slopes, and excavations.

• Support in Design Validation: Results from standardized load tests provide critical information for refining design assumptions, selecting materials, and determining installation methods.

• Quality Assurance: Acceptance and suitability tests as outlined help maintain construction quality, minimizing risk of structural failure or non-compliance.

• International Comparability: By following ISO guidance, organizations can ensure that their testing methodologies align with international best practices, facilitating project approvals and cross-border collaboration.

Related Standards

• ISO 7500-1: Metallic materials - Calibration and verification of static uniaxial testing machines - Part 1: For calibration and traceability of force-measuring equipment used in tension tests.
• EN 1997-3 (Eurocode 7): Geotechnical design - Design and execution requirements for geotechnical structures, including provisions for test numbers and limiting criteria.
• EN 1990: Basis of structural and geotechnical design.
• EN 1992-1-1: Design of concrete structures.
• EN 1993-5: Design of steel structures.
• EN 14490: Execution standard for soil nailing, referenced for test element installation procedures.

Adhering to ISO 22477-6:2026 supports robust geotechnical investigation and testing, ultimately contributing to safer, more reliable civil infrastructure globally. For further guidance and the latest updates, consult the ISO website or your national standards body.