ISO 14688-1:2017

Overview

ISO 14688-1:2017 - "Geotechnical investigation and testing - Identification and classification of soil - Part 1: Identification and description" defines rules and procedures for identifying and describing soils for engineering purposes. It provides a flexible, visual-and-manual system for experienced practitioners to record material and mass characteristics (including bedding and discontinuities), and is intended to be read together with ISO 14688‑2 (principles for classification). The standard applies to natural, man‑made and synthetic soils used in geotechnical projects.

Key topics and technical requirements

• Rules for soil identification and description using visual and hand-test techniques (Clauses 4–6).
• Material types covered: mineral soils, organic soils, carbonate, sulfide, volcanic soils, loess, glacial soils and anthropogenic soils (Clauses 5.1–5.9).
• Soil properties to record: particle size distribution, particle shape and strength, mineral composition, fines content, plasticity/consistency, colour, organic and carbonate content, degree of peat decomposition (Clause 6).
• Mass characteristics: bedding, discontinuities, interbedding and mixed soils (Clause 7).
• Reporting requirements: how to document identifications and descriptions for engineering use (Clause 8).
• Support materials: informative Annex A on procedures to identify the primary fraction in mineral soils and a bibliography.
• References and interactions with related standards (e.g., Atterberg limits referenced via ISO 14688‑2; rocks handled by ISO 14689‑1).

Practical applications

• Standardizes field and laboratory descriptions used in geotechnical site investigations, foundation design, slope stability assessments, tunnelling and earthworks.
• Provides consistent terminology and descriptors for geotechnical reports, improving communication among engineers, geologists, contractors and regulators.
• Helps quality‑control of sample descriptions and supports later classification and testing (by linking to ISO 14688‑2).
• Useful when evaluating made ground, fills, engineered backfills and materials intermediate between soil and rock.

Who uses this standard

• Geotechnical engineers and engineering geologists performing site investigations.
• Field engineers, drilling contractors and laboratory technicians preparing descriptive logs.
• Consultants, regulators and infrastructure owners who specify or review ground investigation deliverables.
• Educators and trainers developing curricula on soil description and classification.

Related standards

• ISO 14688‑2 - Principles for a classification (complements Part 1).
• ISO 14689‑1 - Identification and description of rock.
• ISO 25177 - Soil identification/classification for pedology and remediation contexts (different scope).

Keywords: ISO 14688-1:2017, geotechnical investigation, soil identification, soil description, soil classification, field testing, geotechnical standard.