Critical appraisal of the cone penetration method of determining soil plasticity

2006 ◽  
Vol 43 (8) ◽  
pp. 884-888 ◽  
Author(s):  
K Prakash ◽  
A Sridharan
Keyword(s):  
Laboratory Tests ◽  
Critical Appraisal ◽  
Soil Classification ◽  
Liquid Limit ◽  
Cone Penetration ◽  
Soil Plasticity ◽  
Testing Procedures ◽  
Thread Rolling ◽  
Rolling Method ◽  
Undrained Strength

Plasticity is a characteristic feature that all plastic soils possess. It is shown that the soil plasticity is mainly due to undrained cohesion. Soil plasticity characteristics obtained from laboratory tests are reasonable for use only when the testing procedures adopted to determine them measure the factors responsible for the soil plasticity. It is shown that this is the case with the percussion method of liquid limit determination and the 3 mm thread rolling method of plastic limit determination. Further, it is also shown that the results obtained from the cone penetration method cannot represent the soil plasticity fully, as the mechanisms that come into play during testing relate to undrained strength due to both undrained cohesion and undrained friction. It is stressed that the percussion and 3 mm thread rolling methods must be the only ones used to determine the plasticity of soils. The circumstance under which the cone penetration method can be used is also indicated.Key words: clays, laboratory tests, plasticity, soil classification.

scholarly journals Reappraisal of the ASTM/AASHTO Standard Rolling Device Method for Plastic Limit Determination of Fine-Grained Soils

Geosciences ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 247
Author(s):  
Amin Soltani ◽  
Brendan C. O’Kelly
Keyword(s):  
Soil Classification ◽  
Liquid Limit ◽  
Plastic Limit ◽  
Soil Plasticity ◽  
Reference Limit ◽  
Fine Grained ◽  
Fine Grained Soil ◽  
Thread Rolling ◽  
Hand Test ◽  
Repeatability And Reproducibility

Given its apparent limitations, various attempts have been made to develop alternative testing approaches to the standardized rolling-thread plastic limit (PLRT) method (for fine-grained soils), targeting higher degrees of repeatability and reproducibility. Among these, device-rolling techniques, including the method described in ASTM D4318/AASHTO T90 standards, based on original work by Bobrowski and Griekspoor (BG) and which follows the same basic principles as the standard thread-rolling (by hand) test, have been highly underrated by some researchers. To better understand the true potentials and/or limitations of the BG method for soil plasticity determination (i.e., PLBG), this paper presents a critical reappraisal of the PLRT–PLBG relationship using a comprehensive statistical analysis performed on a large and diverse database of 60 PLRT–PLBG test pairs. It is demonstrated that for a given fine-grained soil, the BG and RT methods produce essentially similar PL values. The 95% lower and upper (water content) statistical agreement limits between PLBG and PLRT were, respectively, obtained as −5.03% and +4.51%, and both deemed “statistically insignificant” when compared to the inductively-defined reference limit of ±8% (i.e., the highest possible difference in PLRT based on its repeatability, as reported in the literature). Furthermore, the likelihoods of PLBG underestimating and overestimating PLRT were 50% and 40%, respectively; debunking the notion presented by some researchers that the BG method generally tends to greatly underestimate PLRT. It is also shown that the degree of underestimation/overestimation does not systematically change with changes in basic soil properties; suggesting that the differences between PLBG and PLRT are most likely random in nature. Compared to PLRT, the likelihood of achieving consistent soil classifications employing PLBG (along with the liquid limit) was shown to be 98%, with the identified discrepancies being cases that plot relatively close to the A-Line. As such, PLBG can be used with confidence for soil classification purposes.

Estimation of some properties of Champlain clays with the Swedish fall cone

1977 ◽  
Vol 14 (4) ◽  
pp. 571-581 ◽  
Author(s):  
R. Garneau ◽  
J. P. LeBihan
Keyword(s):  
Void Ratio ◽  
Liquid Limit ◽  
Physical Characteristics ◽  
Unit Weight ◽  
Compression Index ◽  
Cone Penetration ◽  
Testing Procedures ◽  
Preconsolidation Pressure ◽  
Marine Clays

A large number of laboratory tests, carried out to determine index and physical characteristics of Champlain marine clays, using conventional testing procedures and the Swedish fall cone tests, have led to reliable relationships between the cone penetration and certain characteristics.The purpose of this study has been to establish a rapid method of estimating some index and physical characteristics of this clay. The method described in this paper allows the estimation of clay properties, such as liquid limit, compression index, preconsolidation pressure, undisturbed and remolded shear strength, sensitivity, water content, void ratio, and unit weight, within as little as half an hour and using a single undisturbed specimen. When testing according to conventional procedures, the determination of these characteristics takes several days or even weeks.This paper presents the method of estimation and the procedure used to establish the relationships between the results obtained by conventional methods and those derived using the Swedish fall cone.

scholarly journals STABILISASI TANAH LEMPUNG MENGGUNAKAN KERIKIL UNTUK MENINGKATKAN DAYA DUKUNG (CBR) DI LABORATORIUM SEBAGAI BAHAN TIMBUNAN

2018 ◽  
Vol 1 (1) ◽  
pp. 41
Author(s):  
Annisaa Dwiretnani
Keyword(s):  
Carrying Capacity ◽  
Clay Soil ◽  
Soil Classification ◽  
Liquid Limit ◽  
Optimum Moisture Content ◽  
Plasticity Index ◽  
Test Results ◽  
Plastic Limit ◽  
Soil Plasticity ◽  
Cbr Test

Clay is a type of soil that has a high shrinkage when the change in water content. Construction of roads built on clay soil often damaged, eg cracked or bumpy roads would be damaged so that road before reaching the age of the plan. This study analyzes the behavior of clay in the area of Mendalo Darat, Provinsi Jambi, get maximum soil density and optimum moisture content with the addition of gravel 10%, 20%, 30% and 40%, then tested in the from of nature of the soil, the California Bearing Ratio (CBR). The results, according to the Unified Soil Classification System (USCS) methods. The addition of gravel will cause the properties of the soil Liquid Limit (LL) decreased with Plastic Limit (PL) decreased so that the Plasticity Index (PI) decreased. The addition of gravel will be working actively on the CBR test. From the test results obtained, clay that is stabilized with gravel on variations of 10%, 20%, 30% and 40% indicate an increase in crayying capacity soil and significant decrease in plasticity index. On the gravel mixture of 40% there is significant increase in carrying capacity of 11,90% of power support for the original soil, and on the gravel mixture of 40% also decreased index plasticity of 1,21 % of the original soil plasticity index. The smaller the plasticity index, the carrying capacity is getting bigger.Keywords: clay, stabilized, CBR

scholarly journals Review of Recent Developments and Understanding of Atterberg Limits Determinations

Geotechnics ◽  
2021 ◽  
Vol 1 (1) ◽  
pp. 59-75
Author(s):  
Brendan C. O’Kelly
Keyword(s):  
Water Content ◽  
Experimental Testing ◽  
Soil Classification ◽  
Liquid Limit ◽  
Engineering Industry ◽  
Plastic Limit ◽  
Fine Grained ◽  
Limit Test ◽  
Fine Grained Soil ◽  
Thread Rolling

Among the most commonly specified tests in the geotechnical engineering industry, the liquid limit and plastic limit tests are principally used for (i) deducing useful design parameter values from existing correlations with these consistency limits and (ii) for classifying fine-grained soils, typically employing the Casagrande-style plasticity chart. This updated state-of-the-art review paper gives a comprehensive presentation of salient latest research and understanding of soil consistency limits determinations/measurement, elaborating concisely on the many standardized and proposed experimental testing approaches, their various fundamental aspects and possibly pitfalls, as well as some very recent alternative proposals for consistency limits determinations. Specific attention is given to fall cone testing methods advocated (but totally unsuitable) for plastic limit determination; that is, the water content at the plastic–brittle transition point, as defined using the hand rolling of threads method. A framework (utilizing strength-based fall cone-derived parameters) appropriate for correlating shear strength variation with water content over the conventional plastic range is presented. This paper then describes two new fine-grained soil classification system advancements (charts) that do not rely on the thread-rolling plastic limit test, known to have high operator variability, and concludes by discussing alternative and emerging proposals for consistency limits determinations and fine-grained soil classification.

scholarly journals Laboratory Tests and Analyses of the Level of Vibration Suppression of Prototype under Ballast Mats (UBM) in the Ballasted Track Systems

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 313
Author(s):  
Cezary Kraśkiewicz ◽  
Artur Zbiciak ◽  
Kacper Wasilewski ◽  
Anna Al Sabouni-Zawadzka
Keyword(s):  
Mechanical Model ◽  
Laboratory Tests ◽  
Vibration Suppression ◽  
Track Structure ◽  
European Standard ◽  
Static And Dynamic Characteristics ◽  
Vibration Isolators ◽  
Testing Procedures ◽  
Ballasted Track ◽  
German Standard

The present paper is aimed at the analysis of under ballast mats (UBM) which are used in ballasted track structures as vibration isolators and to protect the ballast layer against fast degradation. The mats were tested in the laboratory and afterwards a novel 4-DoF mechanical model of the track structure with UBM was developed. The novelty of this study consists in the comparison of two testing procedures: a procedure based on the popular German standard DIN 45673-5 and a new European standard EN 17282, released in October 2020. Major discrepancies were demonstrated in the determined values of the static and dynamic characteristics using both approaches—especially in reference to the mats with higher stiffness.

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.

scholarly journals Soil classification at Muaro Baru beach of Padang City using CPT data

2021 ◽  
Vol 331 ◽  
pp. 03005
Author(s):  
Rina Yuliet ◽  
Mas Mera ◽  
Krismon Hidayat
Keyword(s):  
Soil Classification ◽  
Soil Profiles ◽  
Sieve Analysis ◽  
Penetration Test ◽  
Empirical Correlations ◽  
Cone Penetration ◽  
Geotechnical Parameters ◽  
Semi Empirical ◽  
Soil Behaviour ◽  
Behaviour Type

Many semi-empiric correlations have been developed to estimate geotechnical parameters based on Cone Penetration Test (CPT) data for various types of soils. This paper aims to classify soil types based on CPT data with several semi-empiric correlations and compare the results of some of these correlations. In this study, the field CPT and the laboratory test were carried out on soil from two closely spaced locations in the estuary area of Muaro Baru, Padang city. The CPT data was used to determine the soil type using several semi-empirical correlations, namely; friction ratios, Schertmann (1978), Robertson and Campanella (1983), and Robertson et al. (1986), then updated by Robertson in 2010. Soil Behaviour Type (SBT) is based on the cone resistance (qc), sleeve friction (qs), and friction ratio (Rf). The Unified Soil Classification System (USCS) is also used to classify soils using sieve analysis. The results showed that from the several semi-empirical correlations obtained compatibility soil classification and soil profiles.

scholarly journals Using CPTs to derive thermal properties of soil

2020 ◽  
Vol 205 ◽  
pp. 04005
Author(s):  
Philip J. Vardon ◽  
Joek Peuchen
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Laboratory Tests ◽  
Field Investigation ◽  
Volumetric Heat Capacity ◽  
Cone Penetration ◽  
Cone Penetration Tests ◽  
Penetration Tests ◽  
Properties Of Soil

A method of utilizing cone penetration tests (CPTs) is presented which gives continuous profiles of both the in situ thermal conductivity and volumetric heat capacity, along with the in situ temperature, for the upper tens of meters of the ground. Correlations from standard CPT results (cone resistance, sleeve friction and pore pressure) are utilized for both thermal conductivity and volumetric heat capacity for saturated soil. These, in conjunction with point-wise thermal conductivity and in situ temperature results using a Thermal CPT (T-CPT), allow accurate continuous profiles to be derived. The CPT-based method is shown via a field investigation supported by laboratory tests to give accurate and robust results.

Evaluation of Suitability of Red Clay from Selected Areas of Gercus Formation, Sulaimaniyah, North Iraq, for the Construction of Embankment Dams

2021 ◽  
pp. 3417-3427
Author(s):  
Amera I. Hussain Hussain ◽  
Ibraheem I. Ibraheem
Keyword(s):  
Ph Value ◽  
Soil Classification ◽  
Liquid Limit ◽  
Dry Density ◽  
Maximum Dry Density ◽  
Red Clay ◽  
Embankment Dams ◽  
Filling Materials ◽  
The North ◽  
Geotechnical Assessment

      In this research, a geotechnical assessment was conducted for clay of the Gercus Formation to determine its suitability for embankment dams. The selected area is located in the north of Iraq. Six samples were collected from two sites in Dokan (Sulaimaniyah) and Haibat Sultan mountain (Koysinjaq), three samples each. Various geotechnical (physical, mechanical and chemical) tests were conducted based on standard specifications.      The results of the grain size test of clay samples showed their conformity with Zone C curves and their suitability for the construction of embankment dams, according to the Iraqi standard for roads and bridges.  The results of the plasticity limits test showed that the soil is made of fine, low plasticity silt (ML), and low plasticity clay (CL), according to the unified standard soil classification. The water content and plasticity limit tests (liquid limit, plastic limit, and plasticity index) demonstrated that these clays are conformable with the limits of the Iraqi standards. The results of the modified compaction test found a maximum dry density value of 1.962 g/cm3 with an optimum moisture content of 11.5%. The results of the permeability index (K) revealed low permeability according to the Das classification and, therefore, showed the suitability of the samples as raw filling materials in the construction of dams. Chemical tests (sulfate content, organic materials content, total dissolved salts, gypsum content, and pH value) showed compatibility with the requirements for the use in dams construction under the Iraqi standard (SoRB/ R5).

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