RETRACTED: An Energy Based Approach to Determine the Plastic Limit of Fine-grained Soil Using Modified Cone Penetrometer

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.

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Review of Recent Developments and Understanding of Atterberg Limits Determinations

Geotechnics ◽

10.3390/geotechnics1010004 ◽

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.

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Effects of A Low-Carbon Emission Additive on Mechanical Properties of Fine-grained Soil under Freeze-Thaw Cycles

Journal of Cleaner Production ◽

10.1016/j.jclepro.2021.127157 ◽

2021 ◽

pp. 127157

Author(s):

Shervin Ahmadi ◽

Hasan Ghasemzadeh ◽

Foad Changizi

Keyword(s):

Mechanical Properties ◽

Carbon Emission ◽

Low Carbon ◽

Freeze Thaw ◽

Fine Grained ◽

Fine Grained Soil ◽

Low Carbon Emission

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Modeling the Compaction Characteristics of Fine-Grained Soils Blended with Tire-Derived Aggregates

Sustainability ◽

10.3390/su13147737 ◽

2021 ◽

Vol 13 (14) ◽

pp. 7737

Author(s):

Amin Soltani ◽

Mahdieh Azimi ◽

Brendan C. O’Kelly

Keyword(s):

Energy Levels ◽

Model Development ◽

Dry Mass ◽

Unit Weight ◽

Power Functions ◽

Compaction Characteristics ◽

Practical Applications ◽

Fine Grained ◽

Practical Procedure ◽

Fine Grained Soil

This study aims at modeling the compaction characteristics of fine-grained soils blended with sand-sized (0.075–4.75 mm) recycled tire-derived aggregates (TDAs). Model development and calibration were performed using a large and diverse database of 100 soil–TDA compaction tests (with the TDA-to-soil dry mass ratio ≤ 30%) assembled from the literature. Following a comprehensive statistical analysis, it is demonstrated that the optimum moisture content (OMC) and maximum dry unit weight (MDUW) for soil–TDA blends (across different soil types, TDA particle sizes and compaction energy levels) can be expressed as universal power functions of the OMC and MDUW of the unamended soil, along with the soil to soil–TDA specific gravity ratio. Employing the Bland–Altman analysis, the 95% upper and lower (water content) agreement limits between the predicted and measured OMC values were, respectively, obtained as +1.09% and −1.23%, both of which can be considered negligible for practical applications. For the MDUW predictions, these limits were calculated as +0.67 and −0.71 kN/m3, which (like the OMC) can be deemed acceptable for prediction purposes. Having established the OMC and MDUW of the unamended fine-grained soil, the empirical models proposed in this study offer a practical procedure towards predicting the compaction characteristics of the soil–TDA blends without the hurdles of performing separate laboratory compaction tests, and thus can be employed in practice for preliminary design assessments and/or soil–TDA optimization studies.

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Assessment for Thermal Conductivity of Frozen Soil Based on Nonlinear Regression and Support Vector Regression Methods

Advances in Civil Engineering ◽

10.1155/2020/8898126 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Fu-Qing Cui ◽

Wei Zhang ◽

Zhi-Yun Liu ◽

Wei Wang ◽

Jian-bing Chen ◽

...

Keyword(s):

Thermal Conductivity ◽

Support Vector Regression ◽

Nonlinear Regression ◽

Prediction Accuracy ◽

Prediction Models ◽

Frozen Soil ◽

Support Vector ◽

Soil Thermal Conductivity ◽

Fine Grained ◽

Fine Grained Soil

The comprehensive understanding of the variation law of soil thermal conductivity is the prerequisite of design and construction of engineering applications in permafrost regions. Compared with the unfrozen soil, the specimen preparation and experimental procedures of frozen soil thermal conductivity testing are more complex and challengeable. In this work, considering for essentially multiphase and porous structural characteristic information reflection of unfrozen soil thermal conductivity, prediction models of frozen soil thermal conductivity using nonlinear regression and Support Vector Regression (SVR) methods have been developed. Thermal conductivity of multiple types of soil samples which are sampled from the Qinghai-Tibet Engineering Corridor (QTEC) are tested by the transient plane source (TPS) method. Correlations of thermal conductivity between unfrozen and frozen soil has been analyzed and recognized. Based on the measurement data of unfrozen soil thermal conductivity, the prediction models of frozen soil thermal conductivity for 7 typical soils in the QTEC are proposed. To further facilitate engineering applications, the prediction models of two soil categories (coarse and fine-grained soil) have also been proposed. The results demonstrate that, compared with nonideal prediction accuracy of using water content and dry density as the fitting parameter, the ternary fitting model has a higher thermal conductivity prediction accuracy for 7 types of frozen soils (more than 98% of the soil specimens’ relative error are within 20%). The SVR model can further improve the frozen soil thermal conductivity prediction accuracy and more than 98% of the soil specimens’ relative error are within 15%. For coarse and fine-grained soil categories, the above two models still have reliable prediction accuracy and determine coefficient (R2) ranges from 0.8 to 0.91, which validates the applicability for small sample soils. This study provides feasible prediction models for frozen soil thermal conductivity and guidelines of the thermal design and freeze-thaw damage prevention for engineering structures in cold regions.

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Physical and Mechanical Properties of Fine-Grained Soil in the Zhejiang-Fujian Coastal Area, China

Marine Georesources and Geotechnology ◽

10.1080/1064119x.2011.558373 ◽

2011 ◽

Vol 29 (4) ◽

pp. 333-345 ◽

Cited By ~ 5

Author(s):

Yuan-Qin Xu ◽

Pei-Ying Li ◽

Ping Li ◽

Le-Jun Liu ◽

Cheng-Xiao Cao ◽

...

Keyword(s):

Mechanical Properties ◽

Coastal Area ◽

Physical And Mechanical Properties ◽

Fine Grained ◽

Fine Grained Soil

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Centrifuge testing of soil–structure interaction effects on cyclic failure potential of fine-grained soil

Earthquake Spectra ◽

10.1177/8755293020981978 ◽

2021 ◽

pp. 875529302098197

Author(s):

Jason M Buenker ◽

Scott J Brandenberg ◽

Jonathan P Stewart

Keyword(s):

Soil Structure ◽

Interaction Effects ◽

Soil Structure Interaction ◽

Centrifuge Testing ◽

Geotechnical Centrifuge ◽

Structure Interaction ◽

Fine Grained ◽

Stiffness Properties ◽

Fine Grained Soil ◽

Strip Footings

We describe two experiments performed on a 9-m-radius geotechnical centrifuge to evaluate dynamic soil–structure interaction effects on the cyclic failure potential of fine-grained soil. Each experiment incorporated three different structures with a range of mass and stiffness properties. Structures were founded on strip footings embedded in a thin layer of sand overlying lightly overconsolidated low-plasticity fine-grained soil. Shaking was applied to the base of the model container, consisting of scaled versions of recorded earthquake ground motions, sweep motions, and step waves. Data recorded during testing were processed and published on the platform DesignSafe. We describe the model configuration, sensor information, shaking events, and data processing procedures and present selected processed data to illustrate key model responses and to provide a benchmark for data use.

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