ISO 14689:2017

Overview

ISO 14689:2017 - "Geotechnical investigation and testing - Identification, description and classification of rock" provides standardized rules for identifying and describing rock material and rock masses for geotechnical and engineering geology use in civil engineering. The standard covers field and sample-based descriptions (cores, rock exposures) and sets out how to record mineralogy, genetic origin, structure, grain size, discontinuities and other engineering-relevant parameters. Note: rock mass classification systems that predict behaviour are outside the scope.

Key topics and technical requirements

The standard defines procedures and terms for consistent rock identification and description, including:

• Rock identification by genetic group (sedimentary, metamorphic, igneous, duricrust), structure (bedded, foliated, massive), grain size and mineralogical composition.
• Rock material description: colour, grain size, unconfined compressive strength, weathering/alteration, carbonate content and degradation.
• Rock mass description: rock types, bedding and structure, discontinuities (orientation, spacing, persistence), weathering of the rock mass.
• Discontinuity parameters: measurement of orientation, spacing, three‑dimensional block shapes, persistence, roughness, aperture, infilling and seepage.
• Fracture indices in cores and guidance on reporting findings for engineering design and construction.
• Informative annexes that aid identification (geological features), classify weathering, and describe discontinuities in 3D.
• Cross-references normative documents: ISO 14688-1 and ISO 14688-2 for soils and intermediate materials.

These topics ensure consistent core logging, site mapping and documentation of rock properties used for geotechnical design.

Practical applications and users

ISO 14689:2017 is intended for professionals involved in ground investigation and geotechnical design, including:

• Geotechnical engineers and engineering geologists performing site investigations
• Drilling and logging teams responsible for core descriptions
• Tunnel, foundation, slope stability and dam designers assessing rock mass conditions
• Contractors and consultants preparing engineering reports or material specifications
• Researchers and regulators standardizing rock description practices

Typical uses include core logging, rock mass mapping, pre-design ground models, material selection for construction and input data for stability analyses.

Related standards

• ISO 14688‑1 / ISO 14688‑2 - Identification, description and classification of soils (referenced for materials intermediate between soil and rock).
• ISRM suggested methods (referenced for additional guidance).

ISO 14689:2017 supports reliable, repeatable rock descriptions and improves communication between site investigation teams and design engineers - critical for safe, cost‑effective civil engineering projects involving rock.