Journal Published Online: 06 April 2020
Volume 44, Issue 1

Variable Rate Piezocone Data Evaluated Using NTH Limit Plasticity Solution



An established effective stress limit plasticity solution for piezocone testing (CPTu) is shown to be compatible for a variety of primarily fine-grained soils that are subjected to variable rate penetration tests covering undrained to partially drained to fully drained conditions. The method is applicable to primarily clays of low overconsolidation ratio < 2.5. Data from 21 variable rate CPTu test series reported in the geotechnical literature are compiled into three categories, including: (a) field CPTu soundings, (b) laboratory 1-g chamber tests, and (c) centrifuge model tests. Using a CPTu theory developed by the Norwegian Institute of Technology (NTH), it is observed that the effective stress friction angle of clays, silty clays, sandy clays, and other fine-grained soils is consistent, regardless of the probe push rate. For 14 of the variable rate CPTu test series, the NTH CPTu solution compares well with the benchmark friction angle from laboratory triaxial testing. Selected example variable rate CPTu series are presented to illustrate the NTH procedures.

Author Information

Ouyang, Zhongkun
Geotechnical Engineering, School of Civil and Construction Engineering, Oregon State University, Corvallis, OR, USA
Mayne, Paul W.
Geosystems Engineering, School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA
Pages: 17
Price: $25.00
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Stock #: GTJ20190183
ISSN: 0149-6115
DOI: 10.1520/GTJ20190183