Document: NRC Regulatory Guide
Document ID: a094549d-8685-4dad-b90f-c28c7d279a53
Document Type: regulatory_guide
Title: Geologic and Geotechnical Site Characterization Investigations for Nuclear Power Plants + HISTORY – HISTORY 08/2021 – DG-1392 , Proposed Revision 3 07/2014 – Periodic Review of Revision 2 – Reviewed with no issues identified 02/2001 – DG-1101 , Proposed Revision 2 (Rev. 3)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2119/ML21194A176.pdf
Revision Date: 2023-05
Chapter: 
Section ID: RG-1.132
CFR Part: 
CFR Title: 

Content:
free fall of controlled height. Representative samples in unconsolidated marine sediments. Samples may be seriously disturbed. Cable-supported piston remains in contact with soil surface during drive. Gravity corer Open core tube attached to drop weight is driven into soil by gravity after free fall. Representative samples at shallow depth in unconsolidated marine sediments. No control of specific recovery ratio. Samples are disturbed. DG-1392, Appendix C, Page C-4 APPENDIX C, Cont’d. METHOD PROCEDURE APPLICABILITY LIMITATIONS 3. Methods of In Situ Testing of Soil and Rock Standard Penetration Test (SPT) Split-barrel sampler is driven into soil by blows of free-falling weight. Blow count for each 15 centimeters (6 inches) of penetration is recorded. Blow count may be used as an index of consistency or density of soil. May be used for detection of changes in consistency or density in clays or sands. May be used with empirical relationships to estimate relative density of clean sand. Extremely unreliable in silts, silty sands, or soils containing gravel. In sands below water table, positive head must be maintained in borehole. Determination of relative density in sands requires site-specific correlation or highly conservative use of published correlations. Results are sensitive to details of apparatus and procedure. The technique should not be applied to soils containing large amounts of cobbles. Cone Penetration Test/Seismic Cone Penetration Test (SCPT) Instrument steel cone is pushed continuously into the ground and measures resistance to penetration, skin friction, and other properties depending on devices incorporated in the cone. SCPT consists of a receiver to conduct downhole seismic test. Detection of changes in consistency, strength, and density in soils ranging from clays to finer gravel. Used to estimate static undrained shear strength of clays, liquefaction potential of cohesionless soils, and, if so instrumented, changes in pore water pressure in