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.

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.

scholarly journals Characterization of Norwegian marine clays with combined shear wave velocity and piezocone cone penetration test (CPTU) data

2010 ◽  
Vol 47 (7) ◽  
pp. 709-718 ◽  
Author(s):  
Michael Long ◽  
Shane Donohue
Keyword(s):  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Small Strain ◽  
Cone Penetration Test ◽  
Research Quality ◽  
Penetration Test ◽  
Cone Penetration ◽  
Tip Resistance ◽  
Marine Clays

A database of research-quality piezocone cone penetration test (CPTU) and shear wave velocity, Vs, information for Norwegian marine clays has been assembled to study the small-strain stiffness relationships for these materials and to examine the potential use of CPTU and Vs data in combination for the purposes of characterizing these soils. Data for sites where high-quality block sampling was carried out have mostly been used. Improvements have been suggested to existing correlations between the small-strain shear modulus, Gmax, or Vs and index properties for these soils. Recent research has shown that CPTU corrected cone tip resistance, qt, and especially the pore pressure measured during CPTUs, u2, and Vs can be measured reliably and repeatably and are not operator or equipment dependant. Therefore, a new soil classification chart involving the normalized cone resistance, Qt, and normalized shear wave velocity, Vs1, or Vs1 and Δu/[Formula: see text] (where u is the pore-water pressure and [Formula: see text] is the in situ vertical effective stress) is presented. Using this chart it is possible to clearly distinguish between clays of different overconsolidation ratios (OCRs).

FIELD ASSESSMENT OF DYNAMIC CONE PENETRATION TEST TO EVALUATE SAND DENSITY

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Abdulrahman M. Hamid ◽  
Saad A. Aiban ◽  
Omar S. Baghabra Al-Amoudi
Keyword(s):  
Field Testing ◽  
Cone Penetration Test ◽  
Engineering Properties ◽  
Dry Density ◽  
Penetration Test ◽  
Cone Penetration ◽  
Replacement Method ◽  
Dynamic Cone Penetration Test ◽  
Dynamic Cone Penetration

Rapid and accurate in-situ measurement of soil properties is still a challenge facing the construction industry and there is a need for new and advanced devices and methods. Dynamic cone penetration test (DCPT) is an effective device used for field exploration and quality assessment of subsoil. DCPT could be used to predict the engineering properties of sand because it is difficult to perform conventional density tests, such as the sand replacement method, especially when loose or submerged sandy soil is encountered. Two cases of DCP field testing were conducted in Al-Jubail and Ras Al-Khair, eastern Saudi Arabia, where the major petrochemical industries are located. These tests were utilized to evaluate the potential use of DCPT to assess the density during the construction of backfills, whereby the nuclear gauge was also used to accurately measure the in situ soil density and water content. The DCP-nuclear gauge data clearly indicated that there is a good correlation between the dry density obtained from the nuclear gauge and the dynamic cone penetration (DCP) readings, which proves that the DCPT is an effective and reliable tool in the assessment of in situ compaction of sand backfills.

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.

Detection of shear zones in a natural clay slope using the cone penetration test and continuous dynamic sampling

2000 ◽  
Vol 37 (3) ◽  
pp. 652-661 ◽  
Author(s):  
Mahmoud Mahmoud ◽  
David Woeller ◽  
Peter K Robertson
Keyword(s):  
Case History ◽  
Shear Zones ◽  
Cone Penetration Test ◽  
Slope Instability ◽  
Clay Soils ◽  
Penetration Test ◽  
Cone Penetration ◽  
Tip Resistance ◽  
Continuous Dynamic ◽  
Dynamic Sampling

The detection of shear zones along which a mass of soil is moving is essential for understanding the state of stability of natural slopes. Weaker zones in clay soils can be identified from low values of cone penetration test (CPT) tip resistance measured during penetration. This paper presents a case history illustrating the identification of softened shear zones in clay soils using the CPT and the observation of shear surfaces using continuous dynamic sampling (CDS). The analysis and interpretation of the CPT data are discussed in relation to the detection of shear surfaces using the CDS at a site with a history of slope instability. Difficulties encountered in identifying shear zones and detecting shear surfaces are discussed.Key words: cone penetration testing, slope stability, in situ testing, case history, shear zone.

Influence of placement method on the in situ density of hydraulic sand fills

1989 ◽  
Vol 26 (3) ◽  
pp. 453-466 ◽  
Author(s):  
J. A. Sladen ◽  
K. J. Hewitt
Keyword(s):  
Key Words ◽  
Cone Penetration Test ◽  
Penetration Test ◽  
Cone Penetration ◽  
Hydraulic Fill ◽  
Factors Affecting ◽  
Placement Method ◽  
Method Of Placement ◽  
Hydraulic Fills

The range of densities achievable by hydraulic placement of sand straddles the boundary between values giving acceptable potential performance and those giving unacceptable potential performance. This has led to concerns over the safety of structures using hydraulic fills, such as the artificial drilling islands in the Canadian Beaufort Sea. Liquefaction failures of hydraulically placed sand have occurred at four or more of these islands. Until recently, the factors affecting in situ density were little understood. Data obtained from several artificial islands are presented and these are used to demonstrate the overwhelming influence of method of placement on in situ density. The possible reasons for this influence and the implications for design are discussed. Recommendations are made for research that, together with conclusions drawn in the paper, should allow hydraulic fills to be used with more confidence in the future. Key words: sand, hydraulic fill, liquefaction, cone penetration test.

Evaluation of relative density profiles of sand fill at a reclaimed site

2006 ◽  
Vol 43 (9) ◽  
pp. 903-914 ◽  
Author(s):  
Ming-Fang Chang ◽  
Gu Yu ◽  
Yung-Mook Na ◽  
Victor Choa
Keyword(s):  
Relative Density ◽  
Density Profile ◽  
Cone Penetration Test ◽  
Penetration Test ◽  
Cone Penetration ◽  
Density Profiles ◽  
Indirect Methods ◽  
Marine Sand

The determination of relative density is an important part of site characterization for reclaimed sand fill. In practice, a direct determination of the relative density profile is not always possible, and very often one has to resort to indirect methods using in situ tests, such as the cone penetration test. The usefulness of the indirect method is strongly affected by the validity of available correlations. This investigation compares relative density profiles of reclaimed sand fill created from a marine sand by two distinctively different placement methods at the Changi East reclamation site in Singapore as obtained using both the direct and indirect methods. For reclaimed fill, the relative density profile is found to be predominantly influenced by the method of sand placement, although the basic characteristics of the sand also have an effect. Existing correlations developed in calibration chamber tests for indirect evaluation of relative density from the cone resistance in silicate sand are found to provide a slight underestimate of the relative density in direct-dumped fill in Changi, mainly because of the high compressibility of the marine sand. On the other hand, inadequate consideration of overconsolidation and variation in particle size from the specific placement process have led to an overestimate of the relative density in hydraulically placed sand fill in Changi using similarly derived correlations.Key words: in situ density, relative density, sand, land reclamation, cone penetration test, sand placement.

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