Soil classification using the cone penetration test

1990 ◽  
Vol 27 (1) ◽  
pp. 151-158 ◽  
Author(s):  
P. K. Robertson
Keyword(s):  
Case History ◽  
Soil Classification ◽  
Cone Penetration Test ◽  
Deep Borehole ◽  
Penetration Test ◽  
Cone Penetration ◽  
Using Data ◽  
New System ◽  
Good Agreement

Several charts exist for evaluating soil type from electric cone penetration test (CPT) data. A new system is proposed based on normalized CPT data. The new charts are based on extensive data available from published and unpublished experience worldwide. The new charts are evaluated using data from a 300 m deep borehole with wire-line CPT. Good agreement was obtained between samples and the CPT data using the new normalized charts. Recommendations are provided concerning the location at which to measure pore pressures during cone penetration. Key words: soil classification, cone penetration test, in situ, case history.

Cone penetration test (CPT)-based soil behaviour type (SBT) classification system — an update

2016 ◽  
Vol 53 (12) ◽  
pp. 1910-1927 ◽  
Author(s):  
P.K. Robertson
Keyword(s):  
Classification System ◽  
Soil Classification ◽  
Cost Effective ◽  
Cone Penetration Test ◽  
Classification Systems ◽  
Penetration Test ◽  
Cone Penetration ◽  
Soil Behaviour ◽  
Behaviour Type

A soil classification system is used to group soils according to shared qualities or characteristics based on simple cost-effective tests. The most common soil classification systems used in geotechnical engineering are based on physical (textural) characteristics such as grain size and plasticity. Ideally, geotechnical engineers would also like to classify soils based on behaviour characteristics that have a strong link to fundamental in situ behaviour. However, existing textural-based classification systems have a weak link to in situ behaviour, since they are measured on disturbed and remolded samples. The cone penetration test (CPT) has been gaining in popularity for site investigations due to the cost-effective, rapid, continuous, and reliable measurements. The most common CPT-based classification systems are based on behaviour characteristics and are often referred to as a soil behaviour type (SBT) classification. However, some confusion exists, since most CPT-based SBT classification systems use textural-based descriptions, such as sand and clay. This paper presents an update of popular CPT-based SBT classification systems to use behaviour-based descriptions. The update includes a method to identify the existence of microstructure in soils, and examples are used to illustrate the advantages and limitations of such a system.

Computerized Cone Penetration Test for Soil Classification

2008 ◽  
Vol 2053 (1) ◽  
pp. 47-64 ◽  
Author(s):  
Murad Y. Abu-Farsakh ◽  
Zhongjie Zhang ◽  
Mehmet Tumay ◽  
Mark Morvant
Keyword(s):  
Classification System ◽  
Soil Classification ◽  
Cone Penetration Test ◽  
Classification Systems ◽  
Fuzzy Classification ◽  
Classification Methods ◽  
Penetration Test ◽  
Cone Penetration ◽  
Cone Tip Resistance ◽  
Tip Resistance

Computerized MS-Windows Visual Basic software of a cone penetration test (CPT) for soil classification was developed as part of an extensive effort to facilitate the implementation of CPT technology in many geotechnical engineering applications. Five CPT soil engineering classification systems were implemented as a handy, user-friendly, software tool for geotechnical engineers. In the probabilistic region estimation and fuzzy classification methods, a conformal transformation is first applied to determine the profile of soil classification index (U) with depth from cone tip resistance (qc) and friction ratio (Rf). A statistical correlation was established in the probabilistic region estimation method between the U index and the compositional soil type given by the Unified Soil Classification System. Conversely, the CPT fuzzy classification emphasizes the certainty of soil behavior. The Schmertmann and Douglas and Olsen methods provide soil classification charts based on cone tip resistance and friction ratio. However, Robertson et al. proposed a three-dimensional classification system that is presented in two charts: one chart uses corrected tip resistance (qt) and friction ratio (Rf); the other chart uses qt and pore pressure parameter (Bq) as input data. Five sites in Louisiana were selected for this study. For each site, CPT tests and the corresponding soil boring results were correlated. The soil classification results obtained using the five different CPT soil classification methods were compared.

Practical aspects of in situ measurements of material damping with the seismic cone penetration test

1993 ◽  
Vol 30 (2) ◽  
pp. 211-219 ◽  
Author(s):  
W. P. Stewart ◽  
R. G. Campanella
Keyword(s):  
Shear Wave ◽  
Cone Penetration Test ◽  
Material Damping ◽  
Penetration Test ◽  
Cone Penetration ◽  
Seismic Shear ◽  
Laboratory Results ◽  
Calculation Methodology ◽  
Seismic Cone Penetration Test

The downhole seismic cone penetration test (SCPT) procedure has been extended to allow the measurement of material damping at small strains at minimum expense while one is measuring shear wave velocity. The nature of damping, the required equipment characteristics, and the recommended procedure and calculation methodology are presented in a practical way. SCPT results from four different sites give results that are in general agreement with laboratory measurements of damping for sands and clays and with values recommended by other authors. It appears, however, that previously reported measurements of damping by borehole methods are higher, by a factor of two or more, when compared with SCPT and laboratory results. Key words : in situ, damping, seismic, shear wave, cone penetrometers, procedures.

Calibration of a Miniature Cone Penetrometer for Highway Applications

1998 ◽  
Vol 1614 (1) ◽  
pp. 8-14 ◽  
Author(s):  
Pradeep U. Kurup ◽  
Mehmet T. Tumay
Keyword(s):  
Ground Improvement ◽  
Cone Penetration Test ◽  
Test System ◽  
Soil Parameters ◽  
Cone Penetrometer ◽  
Penetration Test ◽  
Cone Penetration ◽  
Tip Resistance ◽  
In Situ Investigation

The electronic cone penetrometer is an important in situ investigation tool of choice for site characterization. Application of this proven concept of the cone penetration test (CPT) to highway design and construction control by miniaturization is described. A miniature cone penetrometer with a projected cone area of 2 cm2 has been developed and implemented in a continuous intrusion miniature cone penetration test system (CIMCPT). This device may be used for rapid, accurate, and economical characterization of sites and to determine engineering soil parameters needed in the design of pavements, embankments, and earth structures. The miniature cone penetration test (MCPT) gives finer details than the standard 10-cm2 cross-sectional area reference cone penetrometer. This makes the MCPT attractive for subgrade characterization, quality-control assessment, compaction control of embankments, and assessment of ground improvement effectiveness for transportation infrastructure. In situ calibration of the CIMCPT system was conducted at a highway embankment site in Baton Rouge, Louisiana. MCPT penetration profiles were compared with those obtained by using the standard cone penetrometer at the same site. The tip resistance of the MCPT was 10 percent higher than that of the reference CPT. The sleeve friction and friction ratio of the reference CPT were higher than that of the MCPT by 12 and 23 percent, respectively. Calibration was also performed to determine empirical cone factors required for estimating undrained shear strength from MCPT data.

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