Derivation Of Conventional Geotechnical Parameters From Nuclear Borehole Logging

The radiometric method of measuring density and moisture in-situ with the Russian made probes PPGR and<br>VPGR is calibrated for logging in cased holes. The accuracy of the radiometric gamma-gamma and neutronneutron<br>logging methods depends on the material properties and on the time allowed for the integration of the<br>back-scattered radiation energy, This paper presents case studies describing the accuracy and repeatability of the<br>measurements in monitoring of changes in water content and in density of soils and soil structures.