Abstract
When dealing with slope stability considerations in deposits where sensitive and quick clays might be encountered it is vital to map the extent of these clays. For the geotechnical engineer, the cone penetration test with pore pressure measurement (CPTU) is a powerful tool in this respect. With its combined measurement of tip resistance, pore pressure and sleeve friction, the CPTU holds a great potential for identification of quick and sensitive clays. Such interpretations can be done based on measured data directly or by combining parameters in dimensionless numbers. Amongst the more popular dimensionless numbers are the pore pressure ratio (B q ), the cone resistance number (N m ) and the friction ratio (R f ). Diagrams exist which allow classification of soils based on the combination of such numbers. Robertson (Can Geotech J 27:151–158, 1990) is one widely used example. However, In Norway, it is found that existing diagrams to a large extent fail to identify sensitive and quick clays. Based on a database of 10 Norwegian sites a new set of classification diagrams are presented with focus on identifying quick and sensitive clays. The diagrams are based on a pore pressure ratio where the tip pore pressure is used (u 1 ) rather than the u 2 -position as this is found to better capture the actual collapsible response of sensitive clays. The cone resistance number is modified to also include an effect of overconsolidation (OCR) instead of only accounting for vertical effective overburden. Also, the friction ratio is normalized with pore pressure (u 1 ) rather than the cone resistance. Electrical resistivity values from R-CPTU-soundings are also included in the considerations. The outcome is a set of revised classification diagrams that provides more accurate identification of Norwegian sensitive and quick clays compared to existing classification diagrams.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Begemann HKS (1965) The friction jacket cone as an aid in determining the soil profile. In: Proceedings of the 6th ICSMFE, 2, (17–20). Montreal, 8–15 September
Jones GA, Rust E (1982) Piezometer penetration testing, CUPT. In: Proceedings of the 2nd European Symposium on Penetration Testing, ESOPT-2, 2, (607–614), Amsterdam, 24–27 May
Karlsrud K, Hernandez-Martinez FG (2013) Strength and deformation properties of Norwegian clays from laboratory tests on high-quality block samples. Can Geotech J 50(12):1273–1293
Karlsrud K, Lunne T, Kort DA, Strandvik S (2005) CPTU correlations for clays. International conference on soil mechanics and foundation engineering, 16, Osaka 2005, pp 693–702
Ladd CC, Foott R (1974) New design procedure for stability of soft clays. J Geotech Eng Div ASCE 100(7):763–786
Larsson R, Mulabdic M (1991) Piezocone tests in clay. Swedish Geotechnical Institute, SGI, Report No. 42, 240
NIFS report no 2015-126 2015 Detection of quick clay – final report, Sandven et al. In Norwegian
Olsen RS, Mitchell JK (1995) CPT stress normalization and prediction of soil classification. CPT95, Linköping, 2, (257–262). Sweden, SGI Report 3:95
Robertson PK (1990) Soil classification using cone penetration test. Can Geotech J 27:151–158
Robertson PK, Campanella RG (1983) Interpretation of cone penetrometer tests, Part I sand. Can Geotech J 20(4):718–733
Sandven R (1990) Strength and deformation parameters from piezocone tests. Ph.D. thesis, Norwegian University of Science and Technology
Sandven R, Gylland A, Montafia A, Kåsin K, Pfaffhuber AA, Long M (2016a) In situ detection of sensitive clays – Part I: selected test methods. NGM 2016 Reykjavik Proceedings, 123–132
Sandven R, Gylland A, Montafia A, Kåsin K, Pfaffhuber AA, Long M (2016b) In situ detection of sensitive clays – Part II: results. NGM 2016 Reykjavik Proceedings, 113–122
Schmertmann JH (1978) Guidelines for cone test, performance, and design. Federal Highway Administration, Report FHWA-TS-78209, Washington
Schneider J, Randolph M, Mayne P, Ramsey N (2008) Analysis of factors influencing soil classification using normalized piezocone tip resistance and pore pressure parameters. J Geotech Geoenviron Eng ASCE 134(11):1569–1586
Senneset K, Sandven R, Janbu N (1989) Evaluation of soil parameters from piezocone test. In-situ Test. Soil property for transportation. Transportation Research Record, No. 1235. C., 24–37
Sully JP, Campanella RG, Robertson PK (1988) Overconsolidation ratio of clays from penetration pore water pressures. ASCE J Geotech Eng 114(2):209–215
Valsson SM (2016) Detecting quick clay with CPTu. NGM 2016 Reykjavik Proceedings, 143–152
Acknowledgements
Partners in the NIFS project are greatly acknowledged for the financial support and good discussions throughout the study. The board of the Norwegian Geotechnical Society (NGF) are also acknowledged for financial support. The authors want to extend thanks to Rambøll, Multiconsult, NGI, Norwegian Public Roads Administration and NGU for allowing the use of data in the study. The authors also wish to express their gratitude to the reviewer Dr. Maj Gøril Bæverfjord for her valuable comments.
Author information
Authors and Affiliations
Corresponding author
Editor information
Editors and Affiliations
Rights and permissions
Copyright information
© 2017 Springer International Publishing AG
About this chapter
Cite this chapter
Gylland, A.S., Sandven, R., Montafia, A., Pfaffhuber, A.A., Kåsin, K., Long, M. (2017). CPTU Classification Diagrams for Identification of Sensitive Clays. In: Thakur, V., L'Heureux, JS., Locat, A. (eds) Landslides in Sensitive Clays. Advances in Natural and Technological Hazards Research, vol 46. Springer, Cham. https://doi.org/10.1007/978-3-319-56487-6_5
Download citation
DOI: https://doi.org/10.1007/978-3-319-56487-6_5
Published:
Publisher Name: Springer, Cham
Print ISBN: 978-3-319-56486-9
Online ISBN: 978-3-319-56487-6
eBook Packages: Earth and Environmental ScienceEarth and Environmental Science (R0)