The behavior of a compressible silty fine sand

1999 ◽  
Vol 36 (1) ◽  
pp. 88-101 ◽  
Author(s):  
An-Bin Huang ◽  
Huai-Houh Hsu ◽  
Jia-Wei Chang
Keyword(s):  
Quartz Sand ◽  
Experimental Studies ◽  
Fine Sand ◽  
Silty Sand ◽  
Small Range ◽  
Cone Penetration ◽  
Fines Content ◽  
Cone Penetration Tests ◽  
Extensive Field ◽  
Tip Resistance

Publications associated with sands are often limited to clean (i.e., little fines content), uniform, uncemented silica or quartz sand. On the other hand, the importance of mineral content, particle shapes, as well as gradation to the behavior of sand has long been recognized. Although systematic studies of sands other than clean quartz sand have been limited, there is increasing attention being paid to sands with an appreciable fines content. Because of a major construction project, extensive field and laboratory experiments were performed on a silty fine sand from Mai-Liao, which is located on the central west coast of Taiwan. Results show that Mai-Liao Sand (MLS), a silty sand, can be significantly more compressible than clean quartz sand under static load. The particles of MLS have moderate strength, and significant crushing can be induced by triaxial shearing. As a result, MLS has low dilatancy and a relatively small range of peak friction angles. Cone penetration tests in MLS were conducted in a calibration chamber. Analyses of the data indicate that interpreting cone tip resistance in MLS using methods developed based on clean quartz sand without considering the differences of compressibility can be unrealistic. This paper documents results of the experimental studies on MLS.Key words: silty fine sand, strength, dilatancy, compressibility, crushing, in situ test.

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 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.

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.

Prediction of pile shaft resistance using cone penetration tests (CPTs)

2012 ◽  
Vol 45 ◽  
pp. 74-82 ◽  
Author(s):  
Mohammad Hassan Baziar ◽  
Armin Kashkooli ◽  
Alireza Saeedi-Azizkandi
Keyword(s):  
Cone Penetration ◽  
Shaft Resistance ◽  
Pile Shaft ◽  
Cone Penetration Tests ◽  
Penetration Tests

A Bayesian unsupervised learning approach for identifying soil stratification using cone penetration data

2019 ◽  
Vol 56 (8) ◽  
pp. 1184-1205 ◽  
Author(s):  
Hui Wang ◽  
Xiangrong Wang ◽  
J. Florian Wellmann ◽  
Robert Y. Liang
Keyword(s):  
Computational Cost ◽  
Physical Space ◽  
Soil Classification ◽  
Feature Space ◽  
Soil Behavior ◽  
Cone Penetration ◽  
Soil Layers ◽  
Tip Resistance ◽  
Input Dataset ◽  
Spatial Configurations

This paper presents a novel perspective to understanding the spatial and statistical patterns of a cone penetration dataset and identifying soil stratification using these patterns. Both local consistency in physical space (i.e., along depth) and statistical similarity in feature space (i.e., logQt–logFrspace, where Qtis the normalized tip resistance and Fris the normalized friction ratio, or the Robertson chart) between data points are considered simultaneously. The proposed approach, in essence, consists of two parts: (i) a pattern detection approach using the Bayesian inferential framework and (ii) a pattern interpretation protocol using the Robertson chart. The first part is the mathematical core of the proposed approach, which infers both spatial pattern in physical space and statistical pattern in feature space from the input dataset; the second part converts the abstract patterns into intuitive spatial configurations of multiple soil layers having different soil behavior types. The advantages of the proposed approach include probabilistic soil classification and identification of soil stratification in an automatic and fully unsupervised manner. The proposed approach has been implemented in MATLAB R2015b and Python 3.6, and tested using various datasets including both synthetic and real-world cone penetration test soundings. The results show that the proposed approach can accurately and automatically detect soil layers with quantified uncertainty and reasonable computational cost.

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.

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