ISO 22477-4:2018

Overview

ISO 22477-4:2018 - Geotechnical investigation and testing - Part 4: Testing of piles: dynamic load testing - defines how to perform dynamic axial compression tests on single piles to assess pile compressive resistance. The standard sets out required equipment, measurements and test procedures for a range of dynamic test methods (impact testing, driving formulae, wave equation analysis and multi‑blow testing) and provides informative guidance on post‑test analysis to derive design‑relevant resistances.

Key topics and technical requirements

• Scope and applicability
  • Applies to piles loaded axially in compression and to the pile types listed in EN 1536, EN 12699 and EN 14199.
  • Tests are limited to dynamic load tests on single piles (investigation and control tests).
• Permitted test methods
  • Dynamic impact testing - measurement of strain, acceleration and/or displacement at the pile head vs time.
  • Pile driving formulae - evaluation from blow counts and hammer energy.
  • Wave equation analysis - modelling pile, soil and driving equipment to assess resistance from blow data.
  • Multi‑blow dynamic testing - series of blows producing different pile head displacements/velocities for evaluation.
• Measurements & equipment
  • Specification of transducers and recording for strain, acceleration and displacement, and requirements for loading devices (impact driving systems, drop masses, hammers).
  • Guidance on attachment of transducers, pile extensions and minimum reference separation distances for displacement measurement.
• Test types
  • Investigation tests: sacrificial piles loaded to ultimate limit state.
  • Control tests: working piles loaded to a specified load above serviceability.
• Analysis & reporting
  • Annexes provide non‑prescriptive guidance on driving formulae, wave equation analysis, signal matching, empirical damping, and multi‑blow techniques.
  • Results from dynamic tests must be analysed (per Annex guidance) to be considered equivalent to measured compressive resistance Rc,m for use with EN 1997‑1 (Eurocode 7).

Practical applications and users

• Who uses it: geotechnical engineers, foundation designers, piling contractors, test laboratories, quality control inspectors and project owners.
• Why use it:
  • To verify pile capacity and behaviour during construction.
  • To perform trial (sacrificial) pile investigations and control tests on working piles.
  • To support design decisions and compliance with EN 1997‑1 (useable results for design after appropriate analysis).
  • For construction monitoring, acceptance testing and forensic investigation of pile performance.

Related standards

• EN 1997‑1:2004+A1:2013 (Eurocode 7 - Geotechnical design) - referenced for design equivalence and partial factors.
• EN 1536, EN 12699, EN 14199 - pile type specifications referenced for applicability.
• Use together with ISO 22477 series parts for complementary geotechnical testing guidance.

Keywords: ISO 22477-4:2018, dynamic load testing, pile testing standard, wave equation analysis, dynamic impact testing, pile driving formulae, multi‑blow testing, geotechnical investigation, pile compressive resistance.