Comparison of Measured and Back Estimated Cone Penetration Resistance of Sand

2008 ◽  
Author(s):  
Meen-Wah Gui ◽  
Dong-Sheng Jeng
Keyword(s):  
Penetration Resistance ◽  
Cavity Expansion ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Cone Penetration Resistance ◽  
Expansion Theory ◽  
Cavity Expansion Theory ◽  
Penetration Tests

The application of cavity expansion theory in the back estimation of cone penetration tests conducted in calibration chambers has been carried out by many researchers. However, the theory is seldom employed by centrifuge modelers. Based on the work of spherical cavity expansion of previous researchers, this study proposed an analytical solution that incorporates the effects of cone geometry and surface roughness and the effect of compressibility to estimate the cone tip resistance. The calculated results are compared with the measured cone penetration resistance of four cone penetration tests performed in the centrifuge. The cone penetration tests were conducted in granular soil specimens having relative densities ranging between 54% and 89%. The comparison demonstrates the capacity of the cavity expansion theory in the prediction of the centrifuge cone penetration resistance.

Influence of placement method on the cone penetration resistance of hydraulically placed sand fills

2001 ◽  
Vol 38 (3) ◽  
pp. 592-607 ◽  
Author(s):  
K M Lee
Keyword(s):  
Cone Penetration ◽  
Density Profiles ◽  
Hydraulic Fill ◽  
Dense Sand ◽  
Cone Penetration Tests ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Wide Range ◽  
Penetration Tests

The reclamation for the new airport at Chek Lap Kok in Hong Kong included the placement of a substantial volume of sand fill by various hydraulic placement techniques, which resulted in a wide range of as-placed densities of the sand fill. This paper described the use of cone penetration tests (CPT) on the evaluation of the possible ranges of density achievable by various hydraulic placement methods adopted in the construction of the new airport. The results of the CPT indicated that the placement technique is one of the most important factors in controlling the as-placed density of hydraulically placed sand fill. There is a marked contrast in cone tip resistance (and the associated relative density) profiles for the sand fills formed by subaerial and subaqueous placement methods, in which the cone tip resistance of the sand fill formed by subaerial placement is substantially higher than that of the sand fill formed by subaequeous placement. The results confirm that dense sand fill cannot be formed by subaqueous placement methods. The weakest zone is generally located just beneath the water level where fill is placed by subaqueous discharge.Key words: sand, hydraulic fill, cone penetration test, calibration chamber test, in situ density.

Effect of Stress History and Shallow Embedment on Centrifuge Cone Penetration Tests in Sand

2019 ◽  
Author(s):  
Anamitra Roy ◽  
Shiaohuey Chow ◽  
Conleth O’Loughlin ◽  
Mark Randolph
Keyword(s):  
Silica Sand ◽  
Cone Penetration ◽  
Stress History ◽  
Buried Structures ◽  
Overconsolidation Ratio ◽  
Cone Penetration Tests ◽  
Cone Tip Resistance ◽  
Tip Resistance ◽  
Order Of Magnitude ◽  
Penetration Tests

Abstract The paper investigates the effect of stress history and shallow embedment on centrifuge cone penetration tests in sand. A series of centrifuge cone penetration tests were performed in loose and dense silica sand at g-levels ranging between 20 and 100 with corresponding overconsolidation ratio (OCR) between 1 and 5. Based on the measured cone tip resistance (qc) profiles, improved empirical correlations have been proposed with depth factors (fD) to impart additional flexibility in accurately back predicting sand relative density (RD) at shallow embedment in normally consolidated (NC) sands. The qc - RD correlations are then extended to capture overconsolidation effects in cone tip resistance, which is broadly consistent with the changes in compressibility and in-situ lateral stresses taking place in sands with increasing OCR levels. The proposed expressions allow accurate quantification of depth corrected CPT profiles in soils of varying overconsolidation ratio, for application in the interpretation of model tests on shallow foundations and anchors and in shallowly buried structures such as pipelines. The expressions also have application for interpretation of field CPT profiles where the thickness of interbedded layers is of similar order of magnitude to the cone diameter.

Cone penetration tests in unsaturated silty sands

2016 ◽  
Vol 53 (3) ◽  
pp. 431-444 ◽  
Author(s):  
Hongwei Yang ◽  
Adrian R. Russell
Keyword(s):  
Effective Stress ◽  
Unsaturated Soils ◽  
Penetration Resistance ◽  
Silty Sand ◽  
Cone Penetration ◽  
Confining Stress ◽  
Cone Penetration Tests ◽  
Hydraulic Hysteresis ◽  
Cone Penetration Resistance ◽  
Penetration Tests

Very little is known about how to interpret cone penetration tests (CPTs) when performed in unsaturated soils. The few published studies on CPTs in unsaturated soils have focused on either clean sands or silt. In this study, new results of laboratory-controlled CPTs in an unsaturated silty sand are presented. Silty sand exhibits hydraulic hysteresis and suction hardening. Suction is observed to have a pronounced effect on measured cone penetration resistance. For an isotropic net confining stress of 60 kPa, it is observed that higher suctions give rise to cone penetration resistances that are 50% larger than those for lower suctions. A semi-theoretical correlation is presented that links measured cone penetration resistances to initial relative density and mean effective stress. Suction has an influence on cone penetration resistances through suction hardening, as well as its contribution to effective stress. For this silty sand, it is shown that failing to account for suction may result in significant overestimations and unsafe predictions of soil properties from measured cone penetration resistances.

Influence of particle size on the correlation between shear wave velocity and cone tip resistance

2011 ◽  
Vol 48 (4) ◽  
pp. 599-615 ◽  
Author(s):  
Mourad Karray ◽  
Guy Lefebvre ◽  
Yannic Ethier ◽  
Annick Bigras
Keyword(s):  
Particle Size ◽  
Shear Wave ◽  
Wave Velocity ◽  
Shear Wave Velocity ◽  
Data Bank ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Tip Resistance ◽  
Project Data ◽  
Penetration Tests

The construction of the Péribonka dam involved deep compaction of its foundation using vibroflotation and dynamic compaction. Surface wave testing was used, in addition to classical tests (cone penetration tests (CPTs) and standard penetration tests (SPTs)) for the assessment of vibrocompaction. More than 900 shear wave velocity (Vs) and 1000 CPT profiles were obtained. This set of tests performed prior to and following vibrocompaction constitutes an important data bank, used in this study to establish a relationship between normalized shear wave velocity, Vs1, normalized tip resistance, qc1, and mean grain size, D50. Using the Péribonka project data obtained on fairly coarse sands in conjunction with the Canadian Liquefaction Experiment (CANLEX) project data obtained on fine sands has confirmed the significant effect of particle-size distribution on the relationship between Vs and qc. The paper proposes a correlation between Vs1, qc1, and D50 for uncemented and Holocene-age granular soils in continuity with the relation developed by Wride et al. from the CANLEX project.

Effects of Aging on Freshly Deposited or Densified Calcareous Sands

1996 ◽  
Vol 1547 (1) ◽  
pp. 76-81 ◽  
Author(s):  
Hasan A. Al-Sanad ◽  
Nabil F. Ismael
Keyword(s):  
Field Tests ◽  
Penetration Resistance ◽  
Cone Penetration ◽  
Calcareous Sand ◽  
Cemented Sand ◽  
Cone Penetration Tests ◽  
Effects Of Aging ◽  
Penetration Tests ◽  
Zero Time ◽  
Dynamic Cone Penetration

The effect of aging on the strength and compressibility of calcareous desert sands was examined by laboratory and field tests. The field tests included standard penetration and dynamic cone penetration tests on freshly deposited loose calcareous sand at one site in Kuwait City. The laboratory tests included direct shear, consolidation, and California bearing ratio tests on reconstituted compacted specimens from a naturally cemented sand. These tests were conducted at zero time and after aging for different periods in the laboratory. The results indicate an increase in the shear strength and a reduction in compressibility at a decreasing rate with time. The penetration resistance increased by 100 to 200 percent as a result of aging over a period of 1 year. The changes in strength and compressibility are attributed to mechanical effects resulting from particle interlocking, reorientation, and dispersion and increased friction at a constant effective stress.

A comparison of foundation compaction techniques

1986 ◽  
Vol 23 (3) ◽  
pp. 271-280 ◽  
Author(s):  
Zoltan V. Solymar ◽  
David J. Reed
Keyword(s):  
Detailed Comparison ◽  
Penetration Resistance ◽  
Time Dependent ◽  
Soil Parameters ◽  
Strength Increase ◽  
Cone Penetration ◽  
Industrial Project ◽  
Design Considerations ◽  
Cone Penetration Resistance ◽  
Penetration Tests

Soil investigation programs established the presence of locally loose to medium dense noncohesive foundation materials at three major industrial project sites. It was neccessary to densify these materials to ensure that unacceptable differential settlements did not occur between separate foundations and to reduce the potential for liquefaction of the looser zones in the event of seismic disturbance. Horizontal ground accelerations of 0.05, 0.1, and 0.3 g were used in the respective seismic analyses for the three sites. Four different techniques for in-place compaction were employed to densify the loose to medium dense soils: vibro and impact compaction, compaction piling, and deep blasting.Site descriptions and soil parameters measured are presented. A short explanation of design considerations and production work procedures is followed by a detailed comparison of the improvements obtained, measured in terms of standard or static cone penetration resistance and true relative density. Problems encountered and phenomena observed during performance of the work are described, such as the time-dependent strength increase in disturbed sands. Key words: compaction piling, deep blasting, impact compaction, vibrocompaction, foundation, penetration tests.

scholarly journals Verification of strength resistance of sandy soil using small scale penetrometer tests

2021 ◽  
Vol 30 (2) ◽  
pp. 304-314
Author(s):  
Hiba Saleem ◽  
Asad Aldefae ◽  
Wissam Humaish
Keyword(s):  
Relative Density ◽  
Sandy Soil ◽  
Penetration Resistance ◽  
Small Scale ◽  
Empirical Equations ◽  
Cone Penetrometer ◽  
Cone Penetration ◽  
Angle Of Friction ◽  
Tip Resistance ◽  
Cone Penetration Resistance

This study focuses on utilizing cone penetrometer models to determine strength (resistance) of sandy soil and also assessment how the relative density and the angle of friction effects on the measured cone penetration resistance in sandy soil. Simple empirical equations are used also to determine the cone penetration resistance components such as the sleeve resistance and the tip resistance. Simple comparison is performed between the measured and calculated soil strength and well agreement is noticed between them.

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