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Several biopolymer applications in geotechnical engineering have been adopted in recent years, notably dust control, soil strengthening, and erosion control. Although biopolymer soil treatment approaches can assure engineering efficiency while satisfying environmental protection standards, this technology requires more validation regarding site adaptability, durability, and economic feasibility. The influence of biopolymers on soil behavior is discussed within geotechnical engineering applications and practices, including soil consistency limits, strength and deformation parameters, hydraulic conductivity, soil-water properties, and erosion prevention. Laboratory studies were performed to confirm the behavior of the treated soil, including Atterberg limits, proctor, and direct shear tests utilizing two types of biopolymers: guar gum and xanthan gum. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Forest & Environment is the property of Journal of Forest & Environment Editorial 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.)

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]

Background: Hyptis suaveolens (L.) Poit., native to the American tropics, is a pantropical annual plant and a major invasive species throughout India. It was anticipated that the availability of sunlight, coupled with its superior reproductive potential, persistent propagule bank, and dispersal ability, could lead to an increase in the growth and spread of this invader, thus potentially impeding herbaceous growth and diversity in non-native areas. Clarifying its ecological fitness and competitive performance will be useful to manage the spread of H. suaveolens in natural ecosystems that are facing a wide range of anthropogenic pressures. Methods: The present study is a three-tier experiment. In the first tier, a field study was conducted to assess the patterns of H. suaveolens abundance and herbaceous species diversity in response to light availability (sun, 842–1072 µmol m–2 s−1 and shade 253–341 µmol m–2 s−1) in the tropical dry deciduous ecosystems in the Vindhyan highlands, India. Furthermore, the impact of H. suaveolens abundance on the resident native and non-native species abundance and diversity was also studied. In the second tier, a randomized common garden experiment was conducted to understand the trait fitness of H. suaveolens in sun (940 µmol m–2 s−1) and shade (300 µmol m–2 s−1) conditions. In the third tier, a plant growth chamber experiment with high-light (940 µmol m–2 s−1) and low-light (300 µmol m–2 s−1) treatments was done to learn how H. suaveolens partitions its biomass between aboveground and belowground plant parts. Results: The field study indicated that the sunlit areas had a higher abundance of H. suaveolens and a lower diversity of resident herbaceous species than the shaded areas. The common garden experiment showed that sun-dwelling H. suaveolens individuals performed better in germinative, vegetative, eco-physiological, and reproductive traits than the shade-dwelling individuals. The growth chamber experiment exhibited that plants grown in high-light environment had greater seed germination, seedling recruitment, and aboveground biomass than those grown in low-light environment, whereas plants grown in low-light environment exhibited a higher root mass ratio than the high-light individuals. These results suggest that H. suaveolens individuals mask the understory vegetation owing to higher seedling recruitment, relative growth rate, photosynthetic performance, resource acquisition-allocation, and reproductive output in response to high-light conditions. Conclusions: The study concludes that light significantly controls the invasive population dynamics of H. suaveolens in dry deciduous forests. In high-light areas, H. suaveolens populations dominate the forest understory with suboptimal shade tolerance. In shade environment, H. suaveolens maintains a persistent soil seed bank along with 'Oskar individuals' that become active in response to high-light availability. The modus operandi is a 'sit and wait' strategy. The current study provides insights on prioritizing areas for H. suaveolens management that will potentially reduce the risk of biological invasions on the native species diversity of tropical regions. [ABSTRACT FROM AUTHOR]

This study delves into the necessity of surface treatment for pure nickel, with a primary focus on applying abrasive jet machining (AJM) in conjunction with a microcontact wear model to investigate the contact interface mechanisms involved in AJM. Experimental findings indicate that SiC particles primarily employ a cutting mechanism to remove asperity peaks on the workpiece surface. While this effectively removes these peaks, it may induce phenomena reminiscent of peen hardening and embedded hardening. Conversely, Al2O3 particles predominantly engage in a rolling extrusion mechanism, leading to noticeable hardening effects akin to peen hardening. The study utilizing microcontact theory derived a 90° erosion wear formula. The study demonstrates that SiC particles outperform Al2O3 particles. SiC particles significantly increase the curvature radius of surface peaks (ρ) and the real contact area (At) during equivalent grinding durations, substantially enhancing workpiece surface quality and service life. Furthermore, post-grinding, an expansion in the elastic deformation region at the particle-workpiece interface, attributed to workpiece surface hardening, mitigates wear, and stabilizes surface roughness. This comprehensive research thoroughly assesses the interfacial effects of different abrasives and grinding parameters, providing valuable insights for related fields. [ABSTRACT FROM AUTHOR]

This study aims to determine the capacity of surface soils, the loading layers of engineered structures with shallow foundations, to swell. For this, five samples were collected using a hand auger at a depth of 1.5–2 meters in the city of Al-Faw in Basra, Iraq. The swelling potential of the soils in the research area was calculated using the clay content, liquid limit, plasticity index, and shrinkage limit values, and the constituent minerals were identified using X-ray diffraction. According to the results of the Atterberg’s limit tests, the soil samples taken from the city of Al-Faw fall into one of three categories: clayey silt low plasticity (ML), clay high plasticity (CH), or silty clay low plasticity (CL). The liquid limit in soil samples ranges between 34-55%, and the plasticity index values range between 12 and 28%. Three samples are of medium swelling potential, while the third location has high swelling potential and the second location has low swelling potential, and the X-ray diffraction data demonstrate that Montmorillonite is the main dominant clay mineral, accounting for an average of 31.88%, followed by Kaolinite mineral, which accounts for an average of 28.984%, Illite, which accounts for an average of 19.5702%, Chlorite, which accounts for an average of 12.1864%, and Palegorskite, which accounts for an average of 7.3688%. [ABSTRACT FROM AUTHOR]

Plasticity index, Ip, is a relatable parameter for most geotechnical engineers, because Ip can be used to estimate other soil properties, such as internal friction angle, compression index, and low-strain shear modulus. Consequently, a method for estimating Ip directly from a piezocone penetration test (CPTU), which measures cone resistance, sleeve friction, and pore pressure would be useful for many practising geotechnical engineers. This technical note presents a method for estimating Ip profiles entirely from CPTU data. The new method has been calibrated using a case database of 258 complementary measurements taken, in natural soils, at 25 globally distributed marine sites. [ABSTRACT FROM AUTHOR]

Weak soils in marine environments present unique challenges for engineering endeavours due to its inherent characteristics and the dynamic nature of aquatic systems. In recent times, the use of nanomaterials has emerged as an effective method for strengthening such soft soils. The present study highlights the effect of nano-titanium dioxide on the strength, plasticity, and compressibility characteristics of marine soil treated with the optimal amount of lime (5%). The potential of nanoparticle in modifying the geotechnical behaviour was examined by adding 0.5%, 0.7%, 1%, and 1.2% of N-TiO2 per unit weight of dry soil. The unconfined compressive strength values of untreated, optimally lime-treated and optimally nano-treated soil specimens were 47 kPa, 467 kPa and 164 kPa, respectively. After 28 days curing period, the unconfined compressive strength of optimally lime-treated marine soil samples mixed with the optimal amount of 0.7% N-TiO2 showed a nine-fold increase to 491 kPa with respect to untreated soil. After the nanotreatment, the liquid limit reduced by 51% and the plasticity index lowered by 74%. This resulted in the improvement of the coefficient of consolidation from 0.001 to 0.004 cm2/s and a reduction in compression index value from 0.39 to 0.17. The microstructure of soil samples was examined using various techniques such as X-ray powder diffraction analysis, Field Emission Scanning Electron Microscopy, Fourier Transform Infrared spectroscopy, and Brunauer–Emmett–Teller surface area analysis. The experimental observations indicate that marine soil treatment using N-TiO2 is a promising technique to improve the geotechnical behaviour of marine soil. [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 Ecoscience (Ecoscience) is the property of Taylor & Francis Ltd 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.)

Copyright of Obras y Proyectos is the property of Universidad Catolica de la Santisima Concepcion 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 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]

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.)

This study focuses on establishing a robust relationship between Standard Penetration Test-N values (SPT-N), geotechnical parameters and unconfined compressive strength (qu) using regression analysis. The proposed relationship offers a reliable method for estimating qu based on SPT-N values. A comprehensive dataset comprising approximately 200 soil samples collected from various boreholes across Dhaka city was utilized. Multiple Linear Regression (MLR), Rando-forest Regression (RFR) and AdaBoost Regression techniques were employed to develop a unified correlation model. Evaluation metrics including R-squared (R2), Mean Absolute Error (MAE) and Root Mean Squared Error (RMSE), along with Trend-behavior Analysis were employed to assess and compare the performances of the models. Additionally, sensitivity analysis was carried out on the selected model in order to assess the importance of each parameter used to predict qu. Finally, the selected model was compared against the existing empirical models that were published in previous studies. In terms of evaluation metrics and Trend-behavior Analysis, the results showed that the RFR model performed better than the others. Additionally, the selected model outperformed the others, demonstrating the highest R2 score, the smallest RMSE and MAE values and lower residuals compared to the previous models. Hence, the proposed model provides accurate predictions of qu for clayey soil in Bangladesh. Its implementation could ensure more efficient geotechnical designs, specifically adjusted to the geological conditions of the Dhaka region. While previous studies have established regional equations for various parts of the world, our model uniquely has incorporated the Plasticity Index (PI) as a predictor for qu and is specifically calibrated for the geological characteristics of Dhaka city. The findings of this study highlight the effectiveness and applicability of regression analysis in predicting qu for Dhaka's soil properties, thus introducing a valuable tool for enhancing the accuracy and effectiveness of geotechnical assessments and design in the region. [ABSTRACT FROM AUTHOR]

The simple but profound standard equation given in BS 1377:1967 is revisited in this paper. According to the equation, plasticity index (PI) is 2.13 times (or simply twice) the linear shrinkage. This standard relationship is widely recognised and employed when determination of the liquid limit or plastic limit is difficult or not possible. The equation is also used as a basic means of checking the accuracy of test results for the Atterberg limits. Data of 180 natural soil samples were used to statistically evaluate the veracity of the equation. It was found that the BS 1377:1967 equation exhibits excellent accuracy and the equation's veracity for practical engineering use was confirmed. However, the method appears to be correct only up to PI values not exceeding 25% and has greater accuracy at lower PI values (<15%). Other studies in the literature also show that the equation may not apply to some soil types or to soils of particular clay mineral types. These possible limitations thus require further investigation. [ABSTRACT FROM AUTHOR]

Soil compaction in the field is conventionally controlled using maximum dry density, (ρd)max, and optimum moisture content, (w)opt, as the target properties. However, achieving accurate control of these target properties can be difficult due to variation of compaction energy level (CEL) and soil type. Recently, a novel soil compaction control approach using optimum degree of saturation, (Sr)opt, as the target properties has been proposed. It was argued that (Sr)opt can be a better compaction control property as the value is less sensitive to the variation of CEL and soil type. This paper presents an investigation of the compaction characteristics of tropical soils from several locations in Indonesia based on both primary and secondary data. This study was performed by exploring the relationships between (i) dry density (ρd) and Sr, (ii) (ρd) and plasticity index (PI), (iii) (ρd) and CBR, as well as (iv) (ρd) and permeability. This study showed that the (Sr)opt of the soils was 91.2%, with variation between 81.2% and 96.5%. This study also showed that (ρd)max can be related to PI at a given CEL. It is expected that the proposed relationships can be better references for field compaction control practices in Indonesia. [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.)

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.)

Bruguiera sexangula (Lour.) Poir is an exclusive evergreen mangrove species to the Sundarbans of Bangladesh. It grows well in moderate saline zones with full sunlight. This study presents leaf morphological plasticity in B. sexangula to saline zones. Leaves were sampled from different saline zones and various morphological traits were measured. The results exposed a wide deviations of leaf size parameters: leaf length varied 6.6–17.3 cm; width 2.7–7.8 cm; upper quarter width 2.2–6.5 cm; down quarter width 2.5–7.3 cm; and petiole length 0.17–1.43 cm. Leaf length was significantly larger in fresh water than in other salinity zones, whereas, leaf width, upper and lower leaf quarters were significantly larger in medium saline zone. Leaf shape parameters showed a large variation among saline zones. Leaf base angle was significantly larger in both medium and strong salinity zones. Tip angle was significantly greater in medium salinity zone. Leaf perimeter was significantly larger in fresh water but leaf area was significantly bigger in medium saline zone. Leaf index and specific leaf area were maximum in moderate saline zone. Plasticity index was the highest in moderate saline for almost all the parameters presented. The ordination (PCA) showed clusters of leaf samples although there were some overlap among them which suggested a salt-stress relationship among salinity zones. The results indicate that B. sexangula had a plasticity strategy on leaf morphological parameters to salinity in the Sundarbans. This study will provide basic information of leaf plasticity of this species among saline zones which will help for site selection of coastal planting and will also provide information for policy makers to take necessary steps for its conservation. [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 influence of stress anisotropy (K) (i.e. the ratio between effective horizontal and vertical stresses) on the shear behaviour of soils has received significant attention in past studies, but how its influence depends on different values of the plasticity index (PI) has not been properly quantified. In this study, the results of a series of undrained triaxial tests on anisotropically consolidated soil at different values of K are reported, and together with past experimental data, the interactive roles of K and PI on the shear behaviour of soil are rigorously interpreted. The findings indicate that the peak shear strength increases with higher brittleness, whereas the peak excess pore pressure diminishes when the value of K decreases. Moreover, increasing the value of PI up to 35 tends to increase the peak shear strength, but beyond that the influence of PI seems marginal. Based on the findings of this study, empirical equations incorporating PI and K to estimate the undrained shear strength are proposed with acceptable accuracy. [ABSTRACT FROM AUTHOR]

Nowadays research in the biopolymers is prominent area for research in medical fields. The metallic implants are used in many numbers for the orthopaedic surgeries. But some unavoidable issues are arising after surgeries like stress-shielding, osteogenesis imperfection, etc. To overcome such issues, re-surgery is only one painful option available for the patient. Sometimes, this option is not feasible for the weak and old patients, which results in increased life risk in such situation. Hence, a biopolymer may be the best solutions to eliminate such problems. Polyether ether ketone (PEEK) and hydroxyapatite (HA) are having biocompatible characteristic with different mechanical properties. Hence in this paper, three different compositions of PEEK-HA are considered and the composites were prepared using compression moulding technique. To compare the mechanical properties for different compositions of PEEK-HA, the porosity and tensile strength were calculated. Unlike the other techniques, the fracture toughness was evaluated through J-integral method to ensure the matching of the cracking phenomenon with the human bone. Tribological properties, for example, wear resistance and plasticity index for all compositions of PEEK and HA were executed in both static and dynamic mode. The result reveals that PEEK5HA can be used for the possible bone replacement. [ABSTRACT FROM AUTHOR]

The current article discusses the integrated geotechnical properties of Buraydah City's foundation beds for the purpose of determining their suitability for development projects, identify the engineering problems impacting the foundation beds as a consequence of the geotechnical behavior of the region under study, and recommend an appropriate solution. Furthermore, the stabilization of sand dunes with palm leaf powder (PLP) is suitable for development projects. Basic laboratory tests such as grain size, Atterberg's limits, free swelling test, chemical analysis, direct shear test, and unconfined compressive strength (UCS) was applied to thirty-nine bore holes (189 samples). X-ray diffraction (XRD) and microscopic analysis were also carried out. The ultimate soil bearing capacity (Qu) values of the examined samples range from 888 to 1412 kN/m2, and elastic settlement extends from 5.40 to 7.96 cm. The investigation results of fine-grained soil at foundation levels reveal that the liquid limit (LL) values range from 25.3 to 54.0%, plastic limit (PL) ranges from 19.2 to 28.0%, plasticity index (PI) ranges from 4.4 to 26.0%, and free swelling ranges from 35.0 to 58.0%. Also, the geotechnical properties of soil and rocks are integrated with Geographic Information System (GIS) to produce the geotechnical model. This model is utilized to recognize the geospatial distribution and categorize the geotechnical hazard in Buraydah City. The produced model illustrated that the geotechnical hazard area observed near from King Abdulaziz road south of the study area. Adding palm leaf powder induces the desired geotechnical properties in the soil of sand dunes. [ABSTRACT FROM AUTHOR]

Clay soils are widely used in constructing embankment dams, levees, highway embankments, sanitary landfills, and hydraulic barriers where they are compacted at maximum dry density and optimum water content. These structures are exposed to many cycles of wetting and drying during their service life, resulting in volume changes and developing shrinkage cracks. This study investigated the effect of density, water content, drying temperature, layer thickness, plasticity index, and multiple wetting and drying cycles on shrinkage crack parameters (length, aperture, and area). Five samples each of low-plasticity clay, medium-plasticity clay, and high-plasticity clay at water contents on both sides of optimum water content were compacted and then oven dried at temperatures of 10°C, 20°C, 30°C, 40°C, and 50°C. Upon complete drying, crack length, aperture, and area were digitally measured. Additionally, we saturated uncompacted clay layers of varying thicknesses (5, 7, 10, 20, and 30 mm) of the three clay types and oven dried them at the listed temperatures to investigate the effect of layer thickness on shrinkage crack parameters. The length, aperture, and area of the cracks were correlated with the influencing factors. Among the compacted samples, only high-plasticity clay samples developed shrinkage cracks, exhibiting an increase in crack length, aperture, and area with an increase in dry density and water content. For the uncompacted samples, crack length and crack area decreased with increasing layer thickness, whereas crack aperture increased. [ABSTRACT FROM AUTHOR]

An effort has been made to perform a detailed characterization of fine-grained soils considering the relative significance of plasticity index for liquefaction risk assessment of the alluvial soil along Indo-Gangetic River banks. To establish this, the author emphasizes the application of computational models in comparison to statistical or empirical approaches for investigation. The novel approach for evaluating the liquefaction risk of fine-grained deposits is performed using different computational models which were satisfactorily validated in the present study. These models consider SPT N-value and peak ground acceleration due to earthquakes along with the consideration of basic geotechnical properties of fine-grained soil. The comparative study suggests that the artificial neural network (ANN) model has achieved the best predictive accuracy as compared to the other four models and it can be used to facilitate the liquefaction risk assessment of fine-grained soil deposits. In addition, liquefaction hazard mapping for the concerned study area is presented based on the ANN model. The artificial intelligence (AI)-based liquefaction mapping technique has high potential as it radically advances risk prediction and preparedness against such seismic events. Also, the influence of some of the significant input parameters on liquefaction susceptibility has been elaborately discussed, in terms of the correlation matrix and relative significance plots. Liquid limit and plasticity index have achieved a relative weightage of 14% and 16%, respectively, for predicting factor of safety (FL), whereas the SPT N-value has the highest impact of 21%. It is also observed that when the magnitude of the earthquake (Mw) is increased substantially from 6 to 7, a severe reduction in FL of 27.04% was noted, whereas for increment in Mw from 7 to 8, 30.5% average reduction in FL was observed. The finding of this study makes a substantial contribution in the field of liquefaction studies using AI models for fine-grained soil with medium to high plasticity. [ABSTRACT FROM AUTHOR]

Geotechnical investigation, in hilly areas, for high-rise projects, becomes a problematic issue and costly process due to difficulties in mobilization and assembling the drilling equipment on mountainous terrains. The objective of this study is to map soil properties of study areas, especially at inaccessible sites, for reconnaissance. Digital soil maps for Tehsil Murree, Pakistan, have been developed using the emerging Geographical Information System (GIS). The research work involved the creation of an exhaustive database, by collecting and rectifying geotechnical data, followed by the digitization of the acquired data through integration with GIS, in an attempt to visualize, analyze and interpret the collected geotechnical information spatially. The soil data of 205 explanatory holes were collected from the available geotechnical investigation (GI) reports. The collection depth of soil samples, which were initially used for the design of deep and shallow foundations by different soil consultancies in the Murree area, was approximately 50 ft. below ground level. Appropriate spatial interpolation methods (i.e., the Kriging) were applied for the preparation of smooth surface maps of soil standard penetration tester number values, soil type and plasticity index. The accuracy of developed SPT N value and plasticity maps were then evaluated using the linear regression method, in which the predicted values of soil characteristics from developed maps and actual values were compared. SPT N value maps were developed up to a depth of 9.14 m below ground level and at every 1.52 m interval. The depth of refusal was considered in the developed maps. Soil type and plasticity maps were generated up to 15.24 m depth, again at every 1.52 m intervals, using color contours, considering the maximum predicted foundation depth for high-rise projects. The study has implications for academics and practitioners to map the soil properties for inaccessible sites using GIS, as the resulting maps have high accuracy. [ABSTRACT FROM AUTHOR]

Background Progesterone is increasingly being used in women at high risk for preterm labor and for maintenance tocolysis. Ultrasound evaluation of uterine in pregnant women in the second trimester of pregnancy can be a predictor of birth complications. Objective To study the effect of vaginal progesterone on uterine by doppler sonography among women in the second and third trimesters of pregnancy who are at risk of preterm labor. Patients and methods A prospective study was carried out on 60 patients attending Obstetrics and Gynecology Department, Menoufia Teaching Hospital, Menoufia, Egypt, during the period from March 2019 to March 2020. The patients were admitted to the hospital for preterm labor, which was arrested by acute tocolysis within 48 h. All participants were subjected to routine baseline investigations and Doppler flow assessment. Results There was a highly statistically significant difference (P < 0.001) in uterine artery pulsatility index (PI) before and after treatment (P = 0.000). Uterine artery PI decreased significantly after treatment (0.817 ± 0.16) than before treatment (0.969 ± 0.27). Uterine artery PI decreased significantly after treatment than before treatment in different periods of gestation (weeks). Moreover, there was no statistically significant difference (P0.05) between the studied women as change in umbilical artery PI before and after treatment in different periods of gestation (weeks). Moreover, uterine artery PI was significantly correlated (P < 0.05) with period of gestation (week) before and after progesterone treatment. Conclusion Uterine artery pulsatility index (PI) decreased significantly after progesterone treatment than before treatment in different periods of gestation (weeks). Umbilical artery PI and middle cerebral artery Doppler PI were not significant different among the studied patients before and after progesterone treatment in different periods of gestation (weeks). Uterine artery PI and middle cerebral artery Doppler PI were negatively associated with period of gestation (week) before and after progesterone treatment. [ABSTRACT FROM AUTHOR]

The shear modulus of a soil, G, shows a hyperbolic degradation curve relationship with increasing shear strain, γ. G is usually normalized against the small-strain modulus (Gmax) as G/Gmax vs γ (log). Factors that significantly influence G are shear strain amplitude, γ, soil plasticity index (PI) and effective pressure, σ′. Design curve charts of G/Gmax vs γ have been produced for seismic engineering purposes. Mathematical models have also been developed, using statistically analysed parameters to reflect the influence of γ, PI and σ′. Soil overconsolidation ratio (OCR) has a significantly lesser impact than the three mentioned factors. In this paper, mathematical fitting and shaping functions for PI and σ′ are developed to extend the shear modulus reduction model further. The requirement to calculate reference strain, γref, is removed, and only soil PI and σ′ are required. Cyclic triaxial experiments are conducted with reconstituted kaolin and bentonite in different mix proportions (to achieve varying PI) and at different effective stresses. The model equation matches well against both the established curves and experimental results and can facilitate preliminary prediction of shear stress–strain behaviour and Gmax with different cohesive soil types and at different depths below ground. [ABSTRACT FROM AUTHOR]

One of the mass prompt practices of soils is for engineering projects such as the construction of roads, buildings, dams, and so on. Therefore, suitability of index and mechanical properties needs to be investigated. This study aims to determine the essential quality material required for road construction, thereby poses détente prospect for the disposal of ineffectual atrophy generated on sites. Such materials are classified into index and mechanical properties. Six subgrade samples were taken at the depth to bottom ranging from (1.0-5.0) m and tested. The sample was subdued to the laboratory tests, such as Sieve Analysis, Atterberg limits, compaction, California Bearing Ratio (CBR), and Specific Gravity (SG) respectively. The mechanical analysis which involved particle size distribution revealed that the subgrade was finely grated with a limit of ≤35% for subgrade passing sieve No. 200 (0.075 mm) with 29.1%, with an average Natural Moist Content (NMC) of 13.9%. The Maximum Dry Density (MDD) and Optimum Moisture Content (OMC) were 1.83 mg/m3 and 11.5%. The index analysis involved the liquid and plastic limits determination of Liquid Limit (LL) of 35.8%, Plastic Limit (PL) of 24.0%, and a Plasticity Index (PI) of 12%. California Bearing Ratio (CBR) results were 20.3% (soaked). The SG test results ranged from (2.68-2.94) kg/m3, employing the American Association of State Highway and Transport Officials (AASHTO) system of soil classification. The AASHTO grouped the materials into A-1, subgroups A-1-b and A-2-4 constituting 50% and 29.1%, with significant materials composed of stone fragments and sand rating the subgrade samples as excellent to good materials suitable for road construction. [ABSTRACT FROM AUTHOR]

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Ten coarse-fine mixtures (CFM) (intermediate soils) having fines contents (FC) of 0%, 12%, 20%, 30%, 40%, and plasticity indices (PI) of 5% and 15% were prepared in the laboratory by mixing different fractions of gravel, sand, nonplastic silt, kaolin, and bentonite. Index properties, volume change during saturation, specific surface area (SSA), and saturated hydraulic conductivity of CFM were investigated. For compacted CFM, a FC=15% (for PI=5%) and FC=12% (for PI=15%) represent the transition between coarse- and fine-dominant behavior based on intergranular void ratio. The total SSA of CFM may be estimated from the weighted average of SSA determined individually for each soil fraction since the SSA of the cohesive portion was observed to be linearly proportional to the percent fractions of kaolin and bentonite. Hydraulic conductivity estimations based on the SSA of soils proposed by the Kozeny–Carman equation underpredicted the hydraulic conductivity of CFM by one to four orders of magnitude. Alternatively, the formulations from consolidation theory and modified Hazen's correlation utilizing effective particle size, D10 , and void ratio, e, estimated the hydraulic conductivity within an order of magnitude. Although hydraulic conductivity decreased with the increase of FC and PI, a smaller amount of decrease was observed in low plastic CFM. [ABSTRACT FROM AUTHOR]

A study on the effect of sisal fibre and waste plastic strips on tropical black clay (also called Black cotton soil, BCS) was carried out. Tests piloted on the natural and treated soil consist of California bearing ratio (CBR), Atterberg limits and compaction for different percentages inclusion of sisal fibre (0, 0.5, 1, 1.5 and 2%) and waste plastic strips (0, 0.5, 1, 1.5 and 2%) by dry weight of soil. Results obtained showed that the liquid limit of BCS initially fluctuated between 43.4% and 55.9% at 1% sisal fibre content, then dropped to 49.4% at 2% sisal fibre content. In the case soil treated with waste plastic strips, liquid values increased from 43.4% for the natural soil to a highest value of 58% at 1% waste plastic strips and thereafter decreased to 49.15% at 2% waste plastic strips content. Plastic limit for both BCS-sisal fibre/waste plastic strips initially decreased from its natural value of 25.78 to 15.55 and 14.77% when treated with sisal fibre and waste plastic strips respectively at 0.5% admixtures content. In the case of plasticity index, values initially increase from its natural value of 17.66% to peak values of 35.39 and 43.23% for sisal fibre and waste plastic strips treated soil respectively, and thereafter decreased. Maximum dry density (MDD) initially increased from 1.55 mg/m3 at 0%, to 1.60 mg/m3 at 0.5% and thereafter decreased to 1.53 mg/m3 at 2% of fibre content. In the case of samples treated with waste plastic strips. The MDD progressively increased as the amount of waste plastic strips increased. OMC show an overall trend of increase for BCS treated with sisal fibre, and a general trend of decrease for soil treated with waste plastic strips. The CBR values initially lessened from their natural value of 13.59% to 4.76% at 1% sisal fibre and subsequently increased to 10.57% at 2% sisal fibre. Similar behaviour was observed for soil modified with waste plastic strips. Based on the results, BCS/waste plastic strips improved the soil more than BCS/sisal fibre treated soil and is recommended at optimal 2% waste plastic strips for geotechnical engineering application such as road payment. [ABSTRACT FROM AUTHOR]

The creep behavior of cohesive soils is highly related to the plasticity index. To study the relationship between the creep and the plasticity index of soils, a creep model is proposed to apply to the creep behavior of several soils with different plasticity indexes, especially covering the very long 80 year monitoring data on-site and 3.5 year test data in the lab. For the same type of soil, the creep exponent does increase with the plasticity index; however, for different types of soils, there is not a clear trend between them. Besides, because the risk of creep failure depends on the creep exponent and the (normalized) stress–strain curve, it is not certain that the creep failure of one type of soil with a larger creep exponent will be quicker than another type of soil with a lower creep exponent. [ABSTRACT FROM AUTHOR]

Intrinsic soil properties, such as the Atterberg limits, are essential factors influencing the mechanical behaviour of the fine-grained soils. In this study, a series of long-term multiple-stage loading oedometer tests were performed on alluvial organic soils to investigate the creep behaviour. The plasticity ratios ranged from 0.4 to 0.63. The smaller value of the plasticity ratio Rp indicated higher soil plasticity. The results showed that the coefficient of secondary compression Cαe of alluvial organic soils was stress- and strain-rate-dependent. The coefficient of secondary compression change index m was derived using a double-logarithmic approach for a creep degradation and was related to the plasticity and clay percentage to fines. Based on the results, it was found that high plasticity soils exhibit slow creep degradation rate during one-dimensional straining under normally consolidated state. The results show that the higher soil plasticity expressed by the plasticity index, plasticity ratio and clay percentage to fines, smaller the coefficient of secondary compression change index. Moreover, the correlations among a soil plasticity properties and creep parameters for the alluvial soils have also been proposed. [ABSTRACT FROM AUTHOR]

The creep behavior of cohesive soils is highly related to the plasticity index. To study the relationship between the creep and the plasticity index of soils, a creep model is proposed to apply to the creep behavior of several soils with different plasticity indexes, especially covering the very long 80 year monitoring data on-site and 3.5 year test data in the lab. For the same type of soil, the creep exponent does increase with the plasticity index; however, for different types of soils, there is not a clear trend between them. Besides, because the risk of creep failure depends on the creep exponent and the (normalized) stress–strain curve, it is not certain that the creep failure of one type of soil with a larger creep exponent will be quicker than another type of soil with a lower creep exponent. [ABSTRACT FROM AUTHOR]

This article explores soil classification methods and the influence of using dispersing agents in various amounts for the soil particle size analysis. Laboratory testing with different dispersing agents was conducted to analyze the effects of sodium hexametaphosphate and lithium carbonate for two different soils with plasticity indices indicating one to be with low plasticity (PI = 8.23 %) and the other one with high plasticity (PI = 39 %). The article highlights differences in the granulometric fractions reported for each soil and usage of the same dispersing agent but in various amount. Thus, the classification of soils is influenced by the amount of the used dispersing agents, recommendations of standards being different in time and countries. These findings contribute to a better understanding of the anticipated behavior of fine soils and provide useful insights for various geotechnical applications. [ABSTRACT FROM AUTHOR]

This research paper is concerned with studying and evaluating the geoengineering characteristics and potential risks of the area under study with a view to safe urban expansion using GIS techniques. Different geotechnical laboratory tests such Atterberg limits, free swelling test, swell potential and pressure tests, chemical analysis, unconfined compressive strength (UCS) and rock quality designation (RQD) were performed on 28 boreholes (95 samples). Furthermore, X-ray diffraction was used to examine clay minerals. The results indicate that the UCS values range from 47 to 72.2 kg/cm2 and RQD from 21 to 45%. The free swell ratio ranges from 110 to 120%, and the plasticity index from 34 to 37%. In addition, GIS techniques have been utilized to produce the distribution layers of different geotechnical characteristics, then integrated to produce a geospatial urban model for delineating and defining safe and dangerous urban zones. This model is classified into four classes: low, moderate, high and very high hazard. Low and moderate hazards were detected in the major portion of the survey area. These portions are suitable for foundations at shallow depths. However, high to very high hazards were detected in the southeast portion of the study area. The reason for these areas is caused by the existence of heavily fractured limestone and highly swelling clay layers. This model would aid in the creation and discovery of the best areas of shallow base in the region under consideration. [ABSTRACT FROM AUTHOR]

Copyright of Investigación e Innovación en Ingenierías is the property of Universidad Simon Bolivar 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.)

Purpose. To determine and evaluate some ceramic properties (plasticity index, linear shrinkage, porosity, and bulk density) of clay deposits from Anambra Basin of South Eastern Nigeria. Methods. Fifteen clay samples were collected by trenching methods. Samples were tested for plasticity index, linear shrinkage, loss on ignition, porosity, and bulk density using test standards developed by the American Society of Test and Materials. Result data were evaluated using tabulation and statistical graphs. Findings. Mean plasticity index of the samples range from 14.3 to 21.3. Mean linear shrinkage is from 2.5 to 5.5%. Mean loss on ignition is from 6.56 to 9.75%. Mean porosities is from 6.9 to 30.1%. Mean bulk density is between 2362 and 1692 kg/m3. The ceramic properties of the deposits varied across location, and no single deposit has the complete set of ceramic properties needed in ceramic industries. Originality. To the best of the authors' knowledge, this is the first research that looked into the distributions of ceramic properties of clay deposits in Anambra geologic Basin. Practical implications. The findings will help investors to make informed decisions on clay deposits in their investment plans and can be used as supporting document when applying for mining titles. [ABSTRACT FROM AUTHOR]

Electrokinetic (EK) treatment is an innovative, cost-effective in situ ground modification technology. The EK treatment uses a combination of low-voltage direct-current, electrodes, and ionic solutions across problematic soil to improve the ground conditions. This study aims to model the effect of changing electrode length (le) on the performance of the EK treatment on the engineering properties of fine-grained problematic soils. The consideration of the changing electrode lengths (le), varying soil depths (ds), and lengthwise anode to cathode distances (dA↔E), in the soil block samples, is in the form of the laboratory model test tank. The significant performance of the experimental tests was with changing electrode lengths of 0.25le (7.5 cm), 0.50le (15.0 cm), 0.75le (22.5 cm), and 1.0le (30.0 cm). The study analyzed the test data obtained from the Atterberg limit and one-dimensional swelling tests at different extraction points of the EK treated soils in the test tanks. Furthermore, the study carefully analyzed the effect of changing electrode length (le) on the performance of the EK treatment. The results of the Design of Experiment (DOE) model analysis revealed that the effect of changing electrode length (le) on the plasticity index (PI), and swelling potential (SP) of the EK treated soils, was significant. For a specific soil depth (ds), the electrode lengths (le) of 0.50le and 0.75le were significantly effective in reducing the PI, and the SP of the EK treated soils. Unlike other studies in the literature, the use of DOE analysis in the present study enabled the detection of the significant input factors and their interactive effects on the PI and the SP, thus, enabling the practicing engineers to navigate accurate design models for large in situ applications. [ABSTRACT FROM AUTHOR]

This article presents a discussion of the paper by Akbay Arama et al. (2021) published in the Arabian Journal of Geosciences, Vol. 14, No. 7, Article 534. Using simple and multiple regression analyses, as well as soft computing artificial neural network (ANN) methods, Akbay Arama et al. (2021) investigated a large database comprising of 1253 Atterberg limits test results for high and very high plasticity clay (CH) soils that are dominant on the European side of Istanbul Province, Turkey. Stated objectives included querying the attainment of the plasticity index (PI) for these soils directly from only liquid limit (LL) test results. Based on regression analyses results, Akbay Arama et al. (2021) produced various correlations relating the PI to LL. Then, employing the Noe (2005) experimental PI–LL dataset, Akbay Arama et al. (2021) reported that their proposed correlations have superior predictive performance compared to those of eight previously reported PI–LL correlations selected (by them). The authors of the present discussion article are of the views that (i) the produced PI–LL correlations for the Istanbul CH soils may not be sufficiently reliable, (ii) it does not seem intuitive to compare the predictive capabilities of these proposed correlations against those previously reported in the literature and deduced for diverse groups of fine-grained soils sourced from geographically different regions, and (iii) since PI–LL correlations cannot definitively and consistently establish the water content corresponding to the experimental plastic–brittle transition point, the thread-rolling test for plastic limit (PL) determination (and hence by association for PI calculation) needs to be retained. Each of these views is elaborated in this article. [ABSTRACT FROM AUTHOR]

Copyright of FME Transactions is the property of University of Belgrade, Faculty of Mechanical Engineering 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.)

Copyright of Nova Scientia is the property of Nova Scientia 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 an attempt to develop a database of the cyclic resistance of fine-grained soils in Indonesia a series of cyclic triaxial test was performed on fine-grained soils collected from two locations near shore of north Java Island, Indonesia. These samples were classified as fine-grained soils with clay-like behavior and, according to various liquefaction criteria, they are non-liquefiable. Our study used a cyclic triaxial test to apply multistage cyclic axial stresses in a form of sinusoidal stress with a frequency of 1 Hz. All specimens are isotropically consolidated passing their preconsolidation stress in order to achieve a normally consolidated state with OCR of about 1. Our findings suggest that cyclic resistance of North Java clay-like fine-grained soils follows the SHANSEP concept and could be normalized at OCR of 1. At fifteen cycles of uniform sinusoidal loading the tested clay and silt samples have a normalized cyclic strength, (qcyc/2)/𝜎c′, or a cyclic resistance ratio (CRR) of approximately 0.31 and a cyclic strength ratio, (qcyc/2)/su, of 0.70. [ABSTRACT FROM AUTHOR]

This article presents a discussion of the Arabian Journal of Geosciences, 394, Vol. 13, No. 11, which (among other things) proposed a new empirical correlation for the prediction of the plasticity index magnitude (and hence by association the plastic limit value) of fine-grained soils sampled from different depths in the Bakırköy District of Istanbul City. As inputs, the proposed correlation employs the activity index, along with defining parameters of the semi-logarithmic flow curve obtained from the Casagrande (percussion-cup) liquid limit test. This article presents the following: (i) a discussion of the relevant literature that was not covered in the original paper; (ii) clarifications on, and observations regarding, the general approach adopted in the original investigation; (iii) concerns over whether the proposed new empirical correlation can be meaningfully recalibrated for particular clay soil types specific to other regions around the world; and (iv) suggestions for improvement of the new empirical correlation by adopting a different set of input parameters. [ABSTRACT FROM AUTHOR]

Background: Geologic and geotechnical conditions of soils where Nanka and Ajali Formations outcropped in Anambra Basin, Southeastern Nigeria were investigated and accessed. This was done using detailed mapping and mechanical soil laboratory tests to unravel the genesis and continued expansion of gully erosion in the study areas. Results: Field study revealed that gully erosions are more pronounced in the study area with poor vegetation cover and a high degree of slope steepness. Grain size analysis revealed that the soils of the Nanka Formation have an average sand content value of 90.90% (sandy) and silt content value of 3.0% (low fine portions). The plasticity index of the fine portions indicates that the soils are weak plastic, with a mean value of 5.29%. The soils have an average cohesion value of 0.30 kg/cm2 indicating a very weak cohesion. The soils are highly permeable; with an average value of 2.67 × 10–3 cm/s. The compaction test further revealed that the soils are loosely compacted. The soils for the Ajali Formation have an average sand content value of 95.10% (sandy) and silt content value of 1.43% (low fine portions). The plasticity index of the fine portions indicates that the soils are weak plastic, with a mean value of 2.70%. The soils have an average cohesion value of 0.30 kg/cm2 indicating a very weak cohesion. The soils are highly permeable; with an average value of 2.70 × 10–3 cm/s. The compaction test revealed that the soils are loosely compacted. Conclusion: After field surveys and laboratory analyses, it was found that the gully erosions have been developing respectively on steep slopes and non-vegetated areas, and their genesis facilitated by the cohesionless and very permeable nature of the sandy formations. Following those key findings, it was proposed many practices (agronomic and engineering mainly) that can help mitigate the formations as well as the expansion of this very damaging hazard type. The potential implications of these gully erosion include damaging of buildings, residential houses, bridges, and roads, loss of farmland and vegetation, isolation of villages and towns, increased migration of inhabitants as well as degradation of agricultural fertile land. [ABSTRACT FROM AUTHOR]

Unbound aggregate base and subbase layers distribute traffic induced wheel loads in a pavement and protect the weak subgrade. In this study, effects of plasticity index (PI), fines content (FC) (per cent passing No. 200 sieve size) and dust ratio (DR) (ratio of per cent passing No. 200 sieve to per cent passing No. 40 sieve) of unbound aggregates on the base/subbase layer modulus and deformation characteristics are investigated. Repeated load triaxial tests were conducted on crushed gravel and limestone specimens prepared at optimum moisture contents for two Illinois dense-graded gradations, i.e. CA 6 and CA 2, to determine the resilient modulus and deformational behaviour. Samples with 9% PI showed lower resilient moduli and greater deformations than samples with 5% PI. The effects of FC on the modulus and deformation behaviour depend on the DR. Increasing DR from 0.4 to 0.6 and eventually to 1.0 increased deformations and decreased resilient moduli at the FC of 5%. An opposite trend was observed when the DR increased from 0.4 to 0.6 and eventually to 1.0 at 12% FC. The test results were used to develop improved resilient modulus and deformation prediction models, which capture important effects of aggregate FC, PI and DR. [ABSTRACT FROM AUTHOR]

Some species intrinsically have a high invasiveness capacity, shown by high phenotypic plasticity and rapid growth, enabling a wide distribution across their native habitats and successful invasion in the introduced range. For such species, information from native habitats is critically important. An example is Glechoma hederacea, native to Eurasia but introduced and widespread in the USA. Our main objective was to investigate variation in traits of native G. hederacea populations across contrasting habitats: open, forest edge and understory. Vegetation was sampled and the ecophysiological and morphological traits were measured with accompanying environmental parameters. Results showed that in native habitats environmental conditions cover wide gradients of light and soil moisture. Plants had the highest cover in nutrient-rich, shaded habitats, representing the optimal habitat, indicating shade tolerance of G. hederacea. Plants from forest understory exhibited strong similarities in investigated traits to plants from the forest edge, even though this was a drier, sunnier habitat. Plants from open, sunny habitats experienced stress as indicated by the quantum efficiency of PSII and significantly higher sexual reproduction. Results show that G. hederacea is moderately tolerant simultaneously to shade and drought, a characteristic that has been reported for numerous invasive species, while at the same time it shares some characteristics with weedy plants. [ABSTRACT FROM AUTHOR]

The present paper presents different approaches which includes plasticity based criteria that helps in distinguish between liquefiable and non-liquefiable soils deposits having fine content. A brief review of the previous work has been mentioned to emphasise on the need of new parameters for liquefaction susceptibility of clayey soils. Clay content, liquid limit and water content are considered as key parameters that helps in liquefaction assessment. Several recommendations proposed by prominent researchers are described here to present wide range of plasticity index, liquid limit and other parameters that affects liquefaction behaviour of clayey soil significantly. But the differences in the range of plasticity index leads to confusion and misperception in determination of liquefaction susceptibility of fine grained soil. One of the high seismic zone site is analyzed using different approach which consider fine content of soil mass. It is found that for a better and proper segregation of the layers Bray and Sancio criteria may be adopted which uses plasticity as one of its input parameter and clearly differentiate site in between liquefiable, non-liquefiable and sites that may liquefy i.e. moderately liquefiable. This summarizes that plasticity is one of the significant criteria which draws a clear differentiating line between liquefiable and non-liquefiable soil deposits. [ABSTRACT FROM AUTHOR]