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Clay swell potential can be classified based on the value of activity and it is defined as the ratio of plasticity index to clay content as a percentage. This paper outlines the investigation into how activity correlates with other key properties of clayey soils. Specifically, four approaches were evaluated for predicting activity using: (a) liquid limit (LL), specific surface area (SSA), cation exchange capacity (CEC) and clay content; (b) LL, SSA and CEC; (c) LL; and (d) SSA and CEC. For this purpose, a database of 104 samples was collected from which 35 machine learning algorithms were trained. Gradient Boosting Trees showed the highest prediction accuracy in the four approaches and, to improve its prediction performance, a Bayesian Optimization was applied to tune theirs hyperparameters, resulting in the final models. The performance of the developed models was evaluated, showing prominent results with exceptionally good metrics, except in the approach from SSA and CEC where the trained algorithm was not capable of predicting activity with confidence (R2=0.46). This algorithm can predict activity using only LL with high accuracy (R2=0.94), and when combined with SSA and CEC, the precision is further enhanced (R2=0.96). [ABSTRACT FROM AUTHOR]

Salinity and sodicity greatly influences ongoing physical processes in soils. Organic matter may rehabilitate physical and mechanical properties of soils. Vermicompost as an amendment influences moisture-related parameters including consistency (plastic – PL and liquid limit – LL) and compaction. This study was conducted on soils (sandy-clay-loam) treated with different salinity levels (0.58 (control – irrigation water quality, tap water), 4 and 8 dS m−1) to investigate the effects of different vermicompost doses (0% (control), 2.5% and 5% w/w) on soil consistency limits and compaction. The pot experiment was carried out in a total of 27 pots, i.e. 3 (vermicompost doses) x 3 (salinity levels) x 3 (number of replicates). For Proctor compaction properties, maximum dry bulk density (MDD) reduced and optimum water contents (OWC) increased with increasing vermicompost doses under different salinity levels (p <.01). Increasing vermicompost doses under the lowest salinity level (0.58 dS m−1) yielded increasing optimum water contents for control (LL = 35.93% and PL = 25.85%). Optimum water contents were determined as 42.19% (LL) and 29.93% (PL) for 2.5% vermicompost dose and as 47.33% (LL) and 36.01% (PL) for 5% vermicompost dose under the lowest salinity level. LL, PL, OWC and MDD were significantly affected by vermicompost x salinity interactions. The highest maximum dry bulk density (1.92 g cm3) and the lowest optimum water contents (13.50%) were obtained from 0% vermicompost under the 8 dS m−1 NaCl level. Mean weight diameter (MWD) values ranged from 0.690 mm for 0% VC treatment under high Na salt level (8 dS m−1 NaCl) to 0.821 mm for 5% VC treatment under lowest Na salt level (0.58 dS m−1 NaCl). The correlations between aggregate stability (particle size group 1–2 mm) and optimum water content were 0.647*, 0.587* and 0.598* as compared to correlations of −0.512*, −0.470*, and −0.617** between aggregate stability (particle size group 1–2 mm) and maximum dry bulk density for the 0, 4 and 8 dS m−1 NaCl levels, respectively. MWD was positively correlated with OWC (0.386*) and negatively correlated with MDD (−0.385*). The greatest (2.39%) and the lowest (0.32%) soil organic matter values were respectively observed in 5% VC under the lowest salinity level (0.58 dS m−1) and 0% VC with at high Na salt level (8 dS m−1 NaCl). It was concluded that vermicompost reduced compaction-induced damage in soils. [ABSTRACT FROM AUTHOR]

Liquid and plastic limits are important parameters of soil hydraulic properties and are important in the research of collapsing gullies. To investigate the specific ion effects on the liquid and plastic limits of collapsing gullies, soil samples from three soil layers in a soil profile（red soil layer, sandy soil layer, and detritus layer) of a stable collapsing gully located in Hetian Town of Changting County, Fujian Province, were collected and exchanged with three kinds of electrolyte solutions（Li+, Na+, and K+) to analyze the liquid and plastic limits. The main results were as follows: the red soil layer had the highest plastic limit, liquid limit, and plasticity index, followed by the sandy soil and detritus layers（P＜0.05). Correlation analysis showed that the clay content, organic matter content, cation exchange capacity, and kaolinite content were positively correlated with the plastic and liquid limits（P＜0.05). Clay and organic matter contents were significantly positively correlated with the plastic limit. The plastic limit, liquid limit, and plasticity index of the red soil layer exchanged with K+ were 5.80%, 9.53%, and 12.99% higher than those exchanged with Li+, and 3.50%, 9.77%, and 15.86% higher than those exchanged with Na+, respectively. The plastic limit, liquid limit, and plasticity index of the sandy soil layer exchanged with K+ were 7.22%, 6.69%, and 6.83% higher than those exchanged with Li+, and 4.33%, 5.27%, and 7.32% higher than those exchanged with Na+, respectively. However, the liquid and plastic limits of the detritus layers did not differ significantly. The liquid and plastic limits of the red and sandy soil layers exchanged for K+ were significantly higher than those exchanged for Li+ and Na+. Therefore, compared with Li+ and Na+, K+ could increase the liquid and plastic limits of collapsing gullies. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ground Improvement is the property of Journal of Ground Improvement Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microplastics (MPs) are greatly released into soils in different ways, specifically through mulching practices in irrigated loess soils in northern Iran as the fertile and susceptible soils to water erosion. This study was conducted to examine the effects of Polyethylene (PE) (a common kind of MPs used in mulching farming in loess soils of north Iran), in a Loess soil under an experimental study. A loess soil was collected from 0- 30 cm surface and incubated at two levels of PE (2.5 and 5 % by weight) in two sizes (1-2 mm and >2mm) for 60 days, at 70% of field capacity moisture and temperature of 25-28 ° C. Soils samples were collected in 1, 15, 30, 45 and 60 days after incubation and different soil chemical, physical, mechanical and biological properties were measured. The results showed that soil pH was significantly (P<0.05) reduced by timing (time after incubation), and application rate of MPs. Inclusion of MPs led to increasing bulk density significantly (P<0.05) and also led to reducing aggregation and mean weight diameter (MWD) compared to control soil. The rate of MWD decreasing varied from 79 % to 87 % in different rates of MPs application. Among the mechanical attributes, liquid limit, plastic limit, and plastic index, all were reduced significantly (P<0.05) after mixing up and incubation with MPs. Reducing aggregation and aeration in treated soils compared to control soils, led to lowering soil microbial respiration, especially with timing. As our results about the effects of MPs in loess soils in a few cases were contrary to other soils studied worldwide, further studies are recommended to perform in loess soils in northern Iran, where receive considerable MPs by farming and open landfill practices in the studied region. [ABSTRACT FROM AUTHOR]

The impact of climate change has become increasingly severe in forests, where droughts and strong winds on the one hand and extreme rainfall events on the other hand can damage forest ecosystems. To mitigate the effects of drought and enhance soil water retention capacity, three types of soil conditioners (SCs), labeled SC_R, SC_CG, and SC_ZZC, were developed as part of the European project ONEforest. All the conditioners are based on Xanthan gum and have different types and amounts of fillers with diverse cellulose fiber lengths. These can offer the potential to optimize the SC characteristics, e.g., water absorption, water retention, and mechanical stability. This paper focuses on the influence of fillers in the SCs on the geotechnical properties of forest soils from Ljubelj in the Alpine part of Slovenia (S1), Catalonia, northeastern Spain (S2), and Heldburg, Germany (S3). The results show an increase of 53% to 100% in the water absorption of treated soil. A less favorable impact of the SCs was found on the drained shear strength and the compressibility. The drained shear strength of untreated forest soils in a saturated state was S1 c′ = 4.4 kPa, φ′ = 33.5°; S2 c′ = 1.4 kPa, φ′ = 30.0°; and S3 c′ = 12 kPa, φ′ = 28.0°. The addition of SCs results in a reduction in the drained shear strength of saturated mixtures. The reduction depends on the dosage of added SC—whether it is a low (L) or a high (H) dosage. For instance, when the soil S1 was treated with a low dosage of the soil conditioner SC_R, it demonstrated a cohesion (c′) of 11 kPa and a friction angle (φ′) of 27.0°. However, increasing the dosage of the SC_R led to a decrease in both the cohesion and the friction angle for the same soil (c′ = 7.7 kPa, φ′ = 25.0°). Additionally, the type of soil conditioner also impacts the drained shear strength. Among the mixtures with a high dosage of the SC_R, SC_CG, or SC_ZZC, those containing the SC_CG with the longest fibers stand out, demonstrating the highest friction angle. Therefore, longer fibers can be a promising component of the SCs to reduce the negative influence of XG on the mechanical properties of treated soils. [ABSTRACT FROM AUTHOR]

Mineralogical and geotechnical properties used to analyse the swelling potentials of Al-Hartha City. According to mineralogy, montmorillonite is a dominated clay mineral (33.61%) followed by montmorillonite-chlorite (33.34%), kaolinite (9.18%) and illite (5.38%). While calcite, Quartz, Feldspar, and dolomite are non-clay minerals that are also present. According to geotechnical analysis, the percent of clay range between 9-42% with an average of 25.5%, silt 55-80% with an average of 67.5% and sand 0-17% with an average of 8.5%. While liquid limits and plasticity index are, respectively, 10–25% with an average of 17.5% and 35%–51% with an average of 43%. According to the unified soil classification system (USCS), these soils are mainly low plasticity lean clay soils (CL) and 10% classified as medium stiff elastic silt (MH). According to activity values, soils are primarily inactive-(70%), normally active-(20%), active-(10%), and their consistency is plastic. according to an assessment of soil expansivity based on index properties and activity, a significant amount of the soil is expansive. Additionally, there is an agreement between the results of the mineralogical tests performed on these soils and the results of the measures of soil expansivity obtained from the evaluation of the swelling of the soil based on assessments of its index properties. [ABSTRACT FROM AUTHOR]

Determining the liquid limit (LL) of fine-grained soils is crucial in geotechnical site investigations. For a long time, the Casagrande Percussion Cup (CPC) test has been the standard method for this purpose. Although the Fall Cone Test (FCT) provides more repeatable results compared to the CPC test, its utilization remains limited in Algeria. To assess the effectiveness of the FCT, a comparative study was conducted using mixtures of bentonite and natural soils from Algeria. The choice of bentonite as an additive to soils with low plasticity is in order to formulate new samples with a wide range of plasticity. Our results showed that the LLCONE values slightly exceeded the LLCUP values for natural soil samples with medium plasticity. However, for soils with high and extreme plasticity, the LLCONE values significantly underestimated the LLCUP values. To address this issue, an equation was developed to convert LLCONE measurements to LLCUP values. This equation is consistent with previous literature and could help promote the adoption of the FCT method for geotechnical site investigations in Algeria. [ABSTRACT FROM AUTHOR]

The aim of this study was to propose a new approach to determine the liquid limit and plastic limit of clay soils by considering electrical conductivity (EC) measurements. The proposed method included incorporating a new parameter, F, which is the ratio of the volumetric water contents of diffuse double layer (DDL) water and free water. In addition, the EC parameter, σ, was considered as the ratio of electrical surface conductivity and electrical conductivity of water. The changes in the thickness of DDL (χ) were also assessed to obtain corresponding equations to establish a connection with clay mineralogy, water content, and specific gravity in the final prediction. Three-dimensional surface analyses were conducted to find a correlation among F, σ, and χ to identify an appropriate method to predict liquid limit and plastic limit. The study was conducted with 39 different types of samples, and the outcomes from the EC approach were validated against the conventional methods. Overall, the coefficient of determination, R2 = 0.90, and Lin's concordance correlation coefficient, (LCCC) = 0.91, were obtained for liquid limit prediction, whereas R2 = 0.64 and LCCC = 0.80 were obtained for plastic limit determination. [ABSTRACT FROM AUTHOR]

With global concerns on carbon emissions, there is increased need for various eco-friendly alternatives to conventional (cement and lime) additives used in ground improvement applications. This paper investigates the effect of three biopolymers—chitin, chitosan, and sodium carboxymethyl cellulose (NaCMC)—on the consistency limits of low plasticity organic silt soil. The theory of soil mechanics suggests that understanding the soil's plasticity nature is helpful in predicting strength and compressibility characteristics. The variation in the Casagrande liquid limit (LL), plastic limit (PL), plasticity index, and flow index of the soil are presented for 0.5–4% chitin and chitosan dosages, and 0.25–1% NaCMC dosage. For all three biopolymers, the consistency limits (more-so for LL than PL) increased with increasing dosage, with NaCMC addition producing a more dramatic effect compared to chitin and chitosan additions. The biopolymer additives formed 'bridge' connections between the soil particles, helping to improve strength properties. This bridging effect explains the significant increases in LL (being essentially a strength-based parameter) for biopolymer addition. A greater LL increase was observed for NaCMC addition since it is a gellable biopolymer with moisture retaining property. [ABSTRACT FROM AUTHOR]

Copyright of Acta Geoscientica Sinica is the property of Acta Geoscientica Sinica Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The northern coastal strip of Venezuela with a semiarid climate presents conditions for the development of extensive areas with the presence of expansive clays, and, this is the main pathology of its communication routes due to deformation in the surrounding civil works. This contribution characterizes the presence of expansive clays in northern Venezuela in 81 samples distributed in several states of the country. The study included the determination of geomechanical properties through field work and laboratory tests by Atterberg limits, consistency indices and expansion tests as well as the relationship between the indexes and information from edometer tests. The soil grain size is mainly fine (silts and clays), in the Anzoátegui state the average content of fine grains is 86%, while in Falcón and Miranda they are a little lower, 82% and 67%, respectively. In general, the plasticity index (PI) of these expansive clays is high, with an overall average of 23, although the region of Falcón state presented a moderate average (18). The correlations between the expansion pressure and the PI showed a high correlation. These results corroborate that the criterion used to evaluate the Expansion Potential of a clay soil based on the PI proposed by Chen (1988), is a fairly adequate criterion to be used in the study and identification of the expansive behavior of these types of soils. [ABSTRACT FROM AUTHOR]

The creep index plays an important role in calculating the long-term settlement of natural soft clays, so it is vital to determine the creep index quickly and accurately. However, the prediction accuracy of the existing creep index models is low. This study presents seven gene expression programming (GEP) models by using different combinations of the liquid limit wL, plasticity index Ip, void ratio e and clay content CI as input variables for the prediction of creep index. A total of 151 datasets were collected from the available literature for building and testing the GEP models. The proposed GEP models were compared with two machine learning (ML) models (i.e., back propagation neural network and random forest) and five conventional empirical models in terms of three statistical indicators. The research results showed that the prediction performances of the two proposed GEP models (i.e., with combinations C I - w L - e and C I - I p - w L - e as input, respectively) surpass those of the five conventional empirical models and two ML-based models, recommended for predicting the creep index of natural soft clays in engineering practice. [ABSTRACT FROM AUTHOR]

This Consolidation settlement is an important aspect of embankment work in various construction projects. This allows an engineer to estimate the value of the consolidation settlement and the length of time the consolidation will take. This study aims to analyze the consolidation settlement based on the consolidation parameters of the empirical relationship with the physical properties of clay soil. The research has begun with a consolidation test and an examination of the physical properties of clay soil on undisturbed soil samples. It has been followed by a search for an empirical relationship between consolidation parameters and clay soil properties. This equation is used to analyze the settlement in clay soils under embankment load. The results of the analysis show that the equations obtained have a similar shape to those from some previous studies. The use of moisture content, void ratio, and liquid limit of clay soil for the analysis of consolidation parameters has yielded positive results in estimating the consolidation settlement due to embankment load. [ABSTRACT FROM AUTHOR]

A large number of mixed soils exist in nature, including sand–clay mixtures, silt–clay mixtures and clay–clay mixtures. The physical parameters of soils are the basis for investigating their mechanical properties (compression, permeability, strength). More importantly, the liquid limits play an important role in establishing the relationships between physical and mechanical properties. The liquid limit tests of sand–clay mixtures were performed on different kinds of original clays with different sand contents. These data together with those compiled from the literature were used to investigate the change in liquid limits of mixed soils. The results show that the liquid limits of mixed soils are influenced by the types of original soils and the contents of each constituent. In sand–clay mixtures, the liquid limits increase with the increasing clay contents. The empirical equation is proposed to predict the liquid limits of sand–clay mixtures based on the liquid limits of original clays and clay contents. By analogy, the method for predicting liquid limits of mixed soils including two types of original soils with known liquid limits is acquired, such as silt–clay mixtures and clay–clay​ mixtures. Such a method is also extrapolated to the mixed soils with more types of original soils.

The aim of this study was to propose a new approach to determine the liquid limit and plastic limit of clay soils by considering electrical conductivity (EC) measurements. The proposed method included incorporating a new parameter, F, which is the ratio of the volumetric water contents of diffuse double layer (DDL) water and free water. In addition, the EC parameter, σ, was considered as the ratio of electrical surface conductivity and electrical conductivity of water. The changes in the thickness of DDL (χ) were also assessed to obtain corresponding equations to establish a connection with clay mineralogy, water content, and specific gravity in the final prediction. Three-dimensional surface analyses were conducted to find a correlation among F, σ, and χ to identify an appropriate method to predict liquid limit and plastic limit. The study was conducted with 39 different types of samples, and the outcomes from the EC approach were validated against the conventional methods. Overall, the coefficient of determination, R2 = 0.90, and Lin’s concordance correlation coefficient, (LCCC) = 0.91, were obtained for liquid limit prediction, whereas R2 = 0.64 and LCCC = 0.80 were obtained for plastic limit determination.

A lot of fieldwork is required to assess the safe bearing capacity (SBC) of fine-grained soil using IS Code, along with performing shear parameters to determine angle of internal friction and cohesion. Standard penetration tests are conducted in order to obtain N-value of soil, and evaluating atterberg limits and dry soil density. Here, it is proposed that Adaptive Neuro-Fuzzy Inference System(ANFIS) is adopted to predict fine-grained soil's safe bearing capacity. For this, input parameters considered for ANFIS system are depth of foundation, dry density, liquid limit, plasticity index, Percentage fine fraction, width/Length ratio, and N-Value. A wide range of safe bearing capacity data from various site locations was investigated and trained on. Four different models were developed with variations in membership function for each input, all the models are used with a gaussbell type of membership function. Among the four, the third model is predicting the nearest value with an R2 of 0.9738. Based on the conclusion the ANFIS model is the most reliable technique for assessing the SBC of soils. Investigation of soil properties and estimation of safe bearing capacity will be having more difficulty with respect to skilled person to investigate and time required is also more as dimension of the footing changes SBC also varies. So, to overcome this type of problems my model will give you a best suitable and reliable SBC.

Many empirical equations have been proposed in the past to predict the parameters of the one-dimensional normal consolidation line (1D-NCL) for soils. However, applications of these equations are limited to specific range of pressure and plasticity soils. General empirical equations for 1D-NCL for large range of pressure and plasticity soils are presented in this study. It is assumed that the 1D-NCL has up to three slopes and these slopes start at different stresses depending on liquid limit (LL) of soils. The 1D-NCL of 59 different soils for a large range of LL (19–520%) was used to establish the initial part of 1D-NCL. The soils were categorized based on their LL into two groups: (i) LL < 110% and (ii) LL > 110%. The equations for initial part of 1D-NCL were compared with the previous empirical 1D-NCL equations. The comparisons showed that the new 1D-NCL equations have a better agreement with tests results, especially for highly plastic soils. Moreover, two soils with different plasticity were used to verify the new 1D-NCL equations. The verifications showed a good agreement between the experimental and the predicted results.

In this study, the effects of acidic and basic tuff additives on the consistency limits and swelling potential of high plasticity clay and the relationship between these properties were investigated. For this purpose, samples containing 5, 10, 15 and 20% acidic tuff and basic tuff additives were compressed at optimum water content, and the consistency limits, swelling pressure and swelling percentage were determined before and after curing for 28 days. The relationship of swelling pressure and swelling percentage changes with consistency limits in pure clay and tuff added samples was investigated. As a result of the experimental studies, decreases in both LL and PI values, and increases and decreases in PI values have occurred with increasing additive ratio and curing effect. Swelling pressure and swelling percentage values of the samples also decreased with increasing additive ratio. According to the results of the regression analysis, it was determined that there were very strong positive relationships between LL, PL and PI of the acidic tuff added samples, with swelling pressure and swelling percentage. In the basic tuff added samples, there was a very strong positive relationship between LL and PI with swelling pressure and swelling percentage, but no significant relationship was found between PL with swelling pressure and swelling percentage. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Xinyang Normal University Natural Science Edition is the property of Journal of Xinyang Normal University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In other words, although soil mineralogy may well play a key role in the varying strength of clays with the water content, I c i SB u(FC) sb mobilised at the FC liquid-limit water content does not respond in any significant way to soil mineralogy; the same conclusion has been previously reported by O'Kelly I et al i . ([16]) employed a Geonor G-200 model 60°-60 g FC device to determine the apparent variations of I c i SB u(FC) sb with the water content about the I w i SB L-FC(BSI) sb (established using the 30°-80 g FC device) for the various fine-grained soils investigated. Keywords: Liquid limit; fall-cone; cone factor; undrained strength; fine-grained soil EN Liquid limit fall-cone cone factor undrained strength fine-grained soil 170 174 5 04/04/23 20230301 NES 230301 It is the authors' opinion that confusion could arise from the analyses and explanations of the experimental fall-cone (FC) results presented in the paper by Nagaraj I et al i . Figure 1(a): An x:y scatter plot showing the changes in undrained shear strength at the British Standard fall-cone liquid-limit water content against the British Standard fall-cone liquid-limit water content for six different fine-grained soils investigated by Nagaraj et al. (2018). [Extracted from the article]

Random and unscientific disposal of municipal waste is an important factor affecting the geotechnical characteristics and concentrations of heavy metals in the soil. Unconfined compressive strength, Atterberg limit, and maximum dry density tests were included. These tests were designed to determine the effects of open waste dumps on geotechnical properties and the concentration of heavy metals in the underlying open dump soil. Soil samples collected from the landfill at Al-Sayyahia Village, Babylon Governorate, showed changes in the rates of geotechnical properties evaluation, as the value of the confined compressive strength decreased by high rates from 54 to 22 kN/m². As well, when comparing the maximum values of dry density of samples from the control site, neighboring the landfill, the average value decreased from 1.91 to 1.74 gm/cm³. Chemical tests revealed that the pH and organic matter percentages in the open dump soil samples were significantly higher than in the control site. These percentages ranged from 9.67% and 2.542% to 7.4% and 0.215%, respectively. In addition, the average value of electrical conductivity was 5.6 mS/cm in the open dump soil, whereas in the control site was 3.6 mS/cm. Iron, lead, Copper, Nickel, Chrome, Zinc, Cadmium, and Arsenic have average concentrations of 4.64%, 14.02, 44.86, 236.36, 278.36, 95.26, 2.034, and 13.84 ppm, respectively. They are higher at open landfill sites than in control site samples. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Soil Science & Plant Nutrition / Toprak Bilimi ve Bitki Besleme Dergisi is the property of Soil Science Society of Turkey and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

According to experimental data results, both inherent anisotropy and loading direction significantly impact geomaterial failures. Clay soils are commonly encountered in many types of on the ground or underground construction, so it is important to understand their behaviour under various stress conditions. Vipulanandan failure model was used to investigate the failure stresses for the soil as compared to the Mohr-Coulomb and other failure models. In this study, over 3000 data from the laboratory studies and literature for the field soils were analysed to quantify the relationship between the density, natural moisture content, shear strength, deviatoric shear stress at failure with the liquid limit (LL). The range of liquid limit (LL) for the soil investigated varied from 20% to 60%. Vipulanandan correlation model correlated some of the physical properties of the soils. The Vipulanandan failure model predicted the results more reliable than the other models based on the coefficient of determination and root mean square error. Vipulanandan failure model also predicted the maximum shear strength limit and maximum second deviatoric stress invariant for the soil, which can not be predicted using the Mohr-Coulomb failure criterion. [ABSTRACT FROM AUTHOR]

Soft clays with high water content are normally treated by cement or cement-based solidifying agent for utilization as geomaterial in the construction of soil structures. The improvement effect of soft clays greatly depends on the water content and content of solidifying agent. It is important to evaluate accurately the improvement effect of clay with different physical or chemical properties for making high-quality improved clay at a low cost. In this study, two types of solidifying agents, namely ordinary Portland cement (OPC) and fly ash-containing solidifying agent (DF), were used for five kinds of clays with different liquid limits (wL) and ignition loss. A cone penetration test was performed on the improved clays to obtain cone index. A new parameter, KL, for representing an effect of content of solidifying agent was introduced by considering liquid limit. An empirical equation of the cone index (qc) with the modified content of solidifying agent (KL) was proposed based on the experimental results. It was clear that parameters on the qc-KL empirical equation relate to liquid limit, ignition loss, and type of solidifying agent. [ABSTRACT FROM AUTHOR]

This paper discusses the use of the Casagrande Cup and Cone Penetrometer Methods for determining the liquid limit of selected organic soils in in the south-eastern region of Poland in laboratory conditions in accordance with the latest standard guidelines. 10 methods established on the basis of literature materials were used to interpret the test results: 4 for test in the Casagrande Cup and 6 for the Cone Penetrometer. The results were compared and used to determine the parameters necessary to assessment of consistency of all type of soils, e.g.: plasticity index ���� (%), consistency index ���� (–) or liquidity index ���� (–). The knowledge of these parameters makes it possible to determine the degree of plasticity of the tested soils using the Cassagrande chart. The conducted research and analyses have shown that the results of determining the liquid limit using the selected methods are not always comparable. The application of calculation methods based on the results of laboratory tests organic soils carried out in accordance with the procedures of the one standard (PN-B-04481: 1988), in the case of interpretation with Method No. 5 and Method No. 7, generated results with the widest range and the highest values in relation to the reference values (Method No. 1). In terms of the suitability of a given method, the type of tested soil, extremely complicated, diverse and heterogeneous structure turned out to be important, and most importantly, the content of organic parts, as evidenced by the results of consistency determination.

The purpose of this study was to assess the performance of high water content clayey sediments at different liquid limits as the clays are treated with cement-based solidifying materials. Three clay samples are obtained from different locations in the Kumamoto Reservoir. Two types of cement-based solidifying agents, namely, ordinary Portland cement and a cement–fly ash binder, were used. Using the initial water content of clay and the mixing amount of the solidifying agent as experimental variables, a cone penetration test was performed on the solidifying agent-stabilized clays to obtain the cone index (qc). The results showed that when the water content to cementitious content ratio (w/AW) was used as a parameter for evaluating the improvement of solidifying agent-stabilized clay, different forms of improvements were observed when different water and solidifying agent contents were used. This implied that the parameter w/AW was not suitable for evaluating the improvement of such clay. A new parameter, K, representing the content of solidifying agent, was introduced to account for the water content. For all sampled clays, the correlation coefficients for the K–ln qc relationship exceeded 0.9. Considering the effect of the liquid limit of the samples, the modified content of the solidifying agent (KL) was introduced to evaluate the cone index of the stabilized soils. It was discovered that the proposed equation unified the assessment of the improvement of the three samples of Kumamoto clayey sediments owing to the new parameter, KL. [ABSTRACT FROM AUTHOR]

A lot of fieldwork is required to assess the safe bearing capacity (SBC) of fine-grained soil using IS Code, along with performing shear parameters to determine angle of internal friction and cohesion. Standard penetration tests are conducted in order to obtain N-value of soil, and evaluating atterberg limits and dry soil density. Here, it is proposed that Adaptive Neuro-Fuzzy Inference System (ANFIS) is adopted to predict fine-grained soil's safe bearing capacity. For this, input parameters considered for ANFIS system are depth of foundation, dry density, liquid limit, plasticity index, Percentage fine fraction, width/Length ratio, and N-Value. A wide range of safe bearing capacity data from various site locations was investigated and trained on. Four different models were developed with variations in membership function for each input, all the models are used with a gaussbell type of membership function. Among the four, the third model is predicting the nearest value with an R2 of 0.9738. Based on the conclusion the ANFIS model is the most reliable technique for assessing the SBC of soils. Investigation of soil properties and estimation of safe bearing capacity will be having more difficulty with respect to skilled person to investigate and time required is also more as dimension of the footing changes SBC also varies. So, to overcome this type of problems my model will give you a best suitable and reliable SBC. [ABSTRACT FROM AUTHOR]

The liquid limit (LL) is considered the most fundamental parameter in soil mechanics for the design and analysis of geotechnical systems. According to the literature, the LL is governed by different particle sizes such as sand content (S), clay content (C), and silt content (M). However, conventional methods do not incorporate the effect of all the influencing factors because traditional methods utilize material passing through a # 40 sieve for LL determination (LL40), which may contain a substantial number of coarse particles. Therefore, recent advancements suggest that the LL must be determined using material passing from a # 200 sieve. However, determining the liquid limit using # 200 sieve material, referred to as LL200 in the laboratory, is a time-consuming and difficult task. In this regard, artificial-intelligence-based techniques are considered the most reliable and robust solutions to such issues. Previous studies have adopted experimental routes to determine LL200 and no such attempt has been made to propose empirical correlation for LL200 determination based on influencing factors such as S, C, M, and LL40. Therefore, this study presents a novel prediction model for the liquid limit based on soil particle sizes smaller than 0.075 mm (# 200 sieve) using gene expression programming (GEP). Laboratory experimental data were utilized to develop a prediction model. The results indicate that the proposed model satisfies all the acceptance requirements of artificial-intelligence-based prediction models in terms of statistical checks such as the correlation coefficient (R2), root-mean-square error (RMSE), mean absolute error (MAE), and relatively squared error (RSE) with minimal error. Sensitivity and parametric studies were also conducted to assess the importance of the individual parameters involved in developing the model. It was observed that LL40 is the most significant parameter, followed by C, M, and S, with sensitivity values of 0.99, 0.93, 0.88, and 0.78, respectively. The model can be utilized in the field with more robustness and has practical applications due to its simple and deterministic nature. [ABSTRACT FROM AUTHOR]

Little is known regarding the effectiveness of biopolymers in soil improvement, especially considering interactions among different clay minerals, porewater cations, and biopolymer polarities. This paper presents an experimental investigation of the effects and effectiveness of four biopolymers of varying polarity and structure (xanthan gum, guar gum, carrageenan, and dextran), on the liquid limit, undrained strength, and thixotropic hardening of soft clays consisting of predominantly kaolinite with lesser montmorillonite. The liquid limits were measured using the standard Casagrande cup method. Fall cone penetration was adapted to determine the development of undrained shear strengths of the samples with time and after remolding. Clay samples were amended by the four biopolymers with a range of concentrations as well as varying NaCl in the pore fluid. Results show different biopolymers affect the consistency and strength behavior of different clays to varying extents; such changes are dominated by the constituent clay minerals’ surface charges as well as the biopolymers’ polarity and structure. Addition of biopolymers to clays results in an immediate gain in undrained shear strength that stabilizes, and some biopolymers exhibit a concentration saturation. Moreover, the neutral biopolymers (guar gum and carrageenan) behave fundamentally differently from anionic xanthan gum and cationic dextran. Advantages and limitations of potential applications of biopolymers in terms of effectiveness, costs, and ease of application are discussed. This research can aid the decision-making processes for coastal geotechnical engineers to determine which of the tested biopolymers presents a safe, cost-effective soil improvement additive for reducing erosion of coastal cohesive soils. [ABSTRACT FROM AUTHOR]

This discussion article provides commenting on the sections of the review paper by Ahmad et al. (the authors) concerning consistency limits determinations for peats and peaty soils, drawing on the writer's experiences regarding the usefulness of liquid limit (LL) and plastic limit (PL) testing/results for these soils in explaining their geotechnical behaviors/properties. From the writer's experience, despite being regularly specified in geotechnical engineering practice and used in research work, the conventional consistency limits tests generally do not produce physically meaningful results when testing peat soils, especially for more fibrous peats. Hence, the writer does not agree with the authors' recommendations on consistency limits testing of peats; namely, they recommended that an utmost effort is needed to improve the quality and standard of the thread rolling test and the fall-cone test for consistency limits determinations of highly organic soils such as peat. Rather than grappling with various known inherent shortcomings of consistency limits testing for peats and other highly organic soils, a suggested way forward for assessing the likely geoengineering behavior/properties of these materials points to the routine measurement of a more useful suite of index tests; namely, their natural water content, organic content, fiber content, and humification (decomposition) level. In this discussion, the above aspects are explored in detail, including greater elaboration of the writer's earlier research work in this area, which was touched on in the authors' paper. [ABSTRACT FROM AUTHOR]