Determining soil water content using Nuclear Magnetic Resonance logging
Tuisku, Joona (2026)
2026
Rakennustekniikan DI-ohjelma - Master's Programme in Civil Engineering
Rakennetun ympäristön tiedekunta - Faculty of Built Environment
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Hyväksymispäivämäärä
2026-03-23
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202603223423
https://urn.fi/URN:NBN:fi:tuni-202603223423
Tiivistelmä
The objective of geotechnical ground investigations is to provide sufficient and reliable data for use in geotechnical design. In the current practice, key parameters such as gravimetric water content and bulk density can only be obtained reliably via sampling, a lengthy and cost-intensive process. NMR (Nuclear Magnetic Resonance) logging is an emerging technology in geotechnical engineering which allows for estimation of the amount of water in the soil, which can be used as a design parameter.
In this thesis NMR logging is studied as a tool to estimate soil properties such as water content, bulk density, grain size distribution and permeability. For this purpose, 7 loggings were made in four sites. These results were validated against laboratory data. The different sites included various soil types ranging from clay to moraine but not including sand or gravel.
NMR logging proved to be a reliable and accurate way to estimate the porosity of soil in fully saturated conditions in connection with related parameters such as gravimetric water content and bulk density. In addition, a fair correlation was found between NMR-derived permeability estimates and laboratory measured permeability values. Decent correlation was found for key grain size distribution parameters d50 and d10 and site-adjusted values of T2ml acquired from the NMR log.
Drawbacks to the current study include lack of data with regards to validation of the im-proved calibration seen with the first probe. More data is needed to establish reliable estimates of permeability and calibrate T2ml correction factors for the Finnish practice. More research is needed to address these gaps.
In this thesis NMR logging is studied as a tool to estimate soil properties such as water content, bulk density, grain size distribution and permeability. For this purpose, 7 loggings were made in four sites. These results were validated against laboratory data. The different sites included various soil types ranging from clay to moraine but not including sand or gravel.
NMR logging proved to be a reliable and accurate way to estimate the porosity of soil in fully saturated conditions in connection with related parameters such as gravimetric water content and bulk density. In addition, a fair correlation was found between NMR-derived permeability estimates and laboratory measured permeability values. Decent correlation was found for key grain size distribution parameters d50 and d10 and site-adjusted values of T2ml acquired from the NMR log.
Drawbacks to the current study include lack of data with regards to validation of the im-proved calibration seen with the first probe. More data is needed to establish reliable estimates of permeability and calibrate T2ml correction factors for the Finnish practice. More research is needed to address these gaps.