4. References

The published sources behind the methods, and the standards and data formats the program relies on. Each method in the methods chapter names the reference it implements; this list gathers them in one place.

4.1. CPT correlations

  • Robertson, P. K. (2009). Interpretation of cone penetration tests - A unified approach. Canadian Geotechnical Journal, 46(11), 1337–1355. The normalised cone parameters, the soil-behaviour-type index, and the iterative stress exponent.

  • Robertson, P. K., & Cabal, K. L. (2015). Guide to Cone Penetration Testing for Geotechnical Engineering. The CPT unit-weight correlation, the soil-behaviour-type chart and zones, the non-normalised index, and the relative-density correlation as tabulated for practice.

  • Jamiolkowski, M., lo Presti, D. C. F., & Manassero, M. (2003). Evaluation of Relative Density and Shear Strength of Sands from CPT and DMT, 201–238. The relative-density correlation for clean sands and its compressibility factor.

  • Lengkeek, A. W., & Brinkgreve, R. B. J. (2022). Automated CPT-based peat identification. The organic and peat boundary extension to the soil-behaviour-type chart.

  • Lunne, T., Robertson, P. K., & Powell, J. J. M. (1997). Cone Penetration Testing in Geotechnical Practice. The standard practitioner text on CPT interpretation, the background to the correlations above.

4.2. Soil mechanics

  • Terzaghi, K., Peck, R. B., & Mesri, G. (1996). Soil Mechanics in Engineering Practice (3rd edition). The effective-stress principle behind the vertical-stress profile.

  • Verruijt, A. (2001). Soil Mechanics. A modern treatment of the same effective-stress principle.

4.3. Soil identification and classification

The lithological descriptions follow the soil-identification standard.

  • NBN (Belgisch normalisatie bureau). (2018). Geotechnical investigation and testing - Identification and classification of soil - Part 1: Identification and description (ISO 14688-1:2018).

  • NBN (Belgisch normalisatie bureau). (2018). Geotechnical investigation and testing - Identification and classification of soil - Part 2: Principles for a classification (ISO 14688-2:2018).

4.4. Field and sampling standards

  • NBN (Belgisch normalisatie bureau). (2023). Geotechnical investigation and testing - Field testing - Part 1: Electrical cone and piezocone penetration test, NBN EN ISO 22476-1:2023. The CPT itself.

  • NBN (Belgisch normalisatie bureau). (2021). Geotechnical investigation and testing - Sampling methods and groundwater measurements - Part 1: Technical principles for the sampling of soil, rock and groundwater (ISO 22475-1:2021). The borehole sampling.

4.5. The NAD classification table

  • NBN (Belgisch normalisatie bureau). (2022). Eurocode 7 : Geotechnisch ontwerp - Deel 1 : Algemene regels - Nationale bijlage (NBN EN 1997-1 ANB), the Belgian national annex to Eurocode 7, Tabel 2.1. The NAD packing-class table (classes 1 to 31, and the characteristic soil parameters per class). The Dutch annex NEN 9997-1 carries an analogous table; it is not the source used here.

4.6. Belgian stratigraphy

The formation names follow the Belgian stratigraphic nomenclature maintained by the National Commission for Stratigraphy Belgium (NCS) (https://ncs.naturalsciences.be).

4.7. Eurocode 7, second generation

  • NBN (Belgisch normalisatie bureau). (2024). Eurocode 7 - Geotechnical design - Part 1: General rules.

  • NBN (Belgisch normalisatie bureau). (2024). Eurocode 7 - Geotechnical design - Part 2: Ground properties.

StrixGeo does not target EC7 design conformance and performs no EC7 design calculation. These are listed because the NAD packing-class table is the Belgian national annex to Eurocode 7, and because the second generation asks for a ground model to be built and maintained per project.

4.8. Data sources and formats

  • GEF, the Geotechnical Exchange Format, the Dutch text format for CPT data that StrixGeo’s GEF importer reads (quantities, measurement variables, coordinate-system codes).

  • DOV, Databank Ondergrond Vlaanderen (https://www.dov.vlaanderen.be), the public Flemish subsurface database, read for CPT and borehole downloads over a bounding box, with the DOV code lists translated at the presentation boundary.