Search Results (295)

Soft soils, characterized by high compressibility, low shear strength, and high water sensitivity, pose serious challenges to geotechnical engineering in infrastructure projects. Traditional stabilization methods such as lime and cement face limitations, including environmental concerns and poor durability under chemical or cyclic loading. Ionic soil stabilizers (ISSs), which operate through electrochemical mechanisms, offer a promising alternative. However, their long-term performance—particularly under environmental stressors such as acid/alkali exposure and cyclic wetting–drying—remains insufficiently explored. This study evaluates the strength and durability of ISS-modified soil through a comprehensive experimental program, including direct shear tests, permeability tests, and cyclic wetting–drying experiments under neutral, acidic (pH = 4), and alkaline (pH = 10) environments. The results demonstrate that ISS treatment increases soil cohesion by up to 75.24% and internal friction angle by 9.50%, particularly under lower moisture conditions (24%). Permeability decreased by 88.4% following stabilization, resulting in only a 10–15% strength loss after water infiltration, compared to 40–50% in untreated soils. Under three cycles of wetting–drying, ISS-treated soils retained high shear strength, especially under acidic conditions, where degradation was minimal. In contrast, alkaline conditions caused a cohesion reduction of approximately 26.53%. These findings confirm the efficacy of ISSs in significantly improving both the mechanical performance and environmental durability of soft soils, offering a sustainable and effective solution for soil stabilization in chemically aggressive environments. Full article

Traditional stabilization techniques, such as lime and cement, widely used for their effectiveness, albeit with economic and environmental limitations, are leading to the search for sustainable approaches that utilize agricultural and industrial waste, such as rice husk ash, bagasse, and natural fibers. These have been shown to improve key geotechnical properties, even under saturated conditions, significantly. In particular, the combination of rice husk ash and recycled ceramics has shown notable results in Ecuadorian coastal soils. The article emphasizes the importance of selecting techniques that balance effectiveness, cost, and sustainability and identifies existing limitations, such as the lack of long-term data (ten years) and predictive models adapted to the Ecuadorian climate. From a bibliographic perspective, this article analyzes the challenges posed by expansive soils in the western coastal region of Ecuador, whose high plasticity and instability to moisture negatively affect civil works such as roads and buildings. The Ecuadorian clay contained 30% kaolinite and only 1.73% CaO, limiting its chemical reactivity compared to soils such as Saudi Arabia, which contained 34.7% montmorillonite and 9.31% CaO. Natural fibers such as jute, with 85% cellulose, improved the soil’s mechanical strength, increasing the UCS by up to 130%. Rice husk ash (97.69% SiO₂) and sugarcane bagasse improved the CBR by 90%, highlighting their potential as sustainable stabilizers. All of this is contextualized within Ecuador’s geoenvironmental conditions, which are influenced by climatic phenomena such as El Niño and La Niña, as well as global warming. Finally, it is proposed to promote multidisciplinary research that fosters more efficient and environmentally responsible solutions for stabilizing expansive soils. Full article

Biopolymers, owing to their environmentally friendly and sustainable characteristics, have become a promising alternative for soil stabilization in geotechnical engineering. The application of protein-based biopolymers as binders for soil stabilization is less prevalent in geotechnical engineering compared to polysaccharide-based biopolymers. This study explores the potential of gelatin, a protein-based biopolymer derived from animal collagen, for stabilizing silty sand and improving its geotechnical properties. Gelatin was mixed into the soil at concentrations ranging from 0.25% to 2% of the dry weight of soil, and its effects on various soil characteristics were evaluated. The tests conducted include liquid limit, plastic limit, compaction behavior, and unconfined compressive strength (UCS); the addition of 1% gelatin led to an approximate 1.69 times increase in the strength of the unamended soil. After 28 days of curing, the UCS improved by approximately 5.03 times compared to the untreated soil, and the treated soil exhibited increased resistance to deformation under load. Microstructural analysis using scanning electron microscopy (SEM) revealed that gelatin facilitated the formation of a cohesive matrix, enhancing particle bonding and reducing void spaces within the soil. Carbon footprint analysis (CFA) conducted on an isolated footing stabilized with gelatin showed that the carbon emissions were reduced by 99.8% and 99% compared to traditional stabilizers such as lime and cement. Additionally, the interaction between the biopolymer and the fine-grained soil is distinctly evident in the FTIR and XRD analysis through hydrogen bonding and the formation of cementitious compounds. Full article

Aminotris(methylene phosphonic acid) (ATMP) and poly(acrylic acid) sodium salt (PAA) have shown favorable results in the treatment of porous building materials against weathering damage, showing promising potential as mixed-in additives during the production of lime-based mortars. This study investigates the impact of these additives on microstructure and mechanical properties. Additives were introduced in various concentrations to assess their influence on CaCO₃ crystallization, porosity, strength, and carbonation behavior. Results revealed significant modifications in the morphology of CaCO₃ precipitates, showing evidence of nanostructured CaCO₃ aggregates and vaterite stabilization, thus indicating a non-classical crystallization pathway through the formation of amorphous CaCO₃ phase(s), facilitated by organic occlusions. These nanostructural changes, resembling biomimetic calcitic precipitates enhanced mechanical performance by enabling plastic deformation and intergranular bridging. Increased porosity and pore connectivity facilitated CO₂ diffusion towards the mortar matrix, contributing to strength development over time. However, high additive concentrations resulted in poor mechanical performance due to the excessive air entrainment capabilities of short-length polymers. Overall, this study demonstrates that the optimized dosages of ATMP and PAA can significantly enhance the durability and mechanical performance of lime-based mortars and suggests a promising alternative for the tailored manufacturing of highly compatible and durable materials for both the restoration of cultural heritage and modern sustainable construction. Full article

Maintenance dredging produces large volumes of fine sediments that are commonly discarded, despite increasing pressure for beneficial reuse. Lime–cement stabilization offers one pathway, yet field performance is highly variable. This study juxtaposes two French marine dredged sediments—DS-F (low plasticity, organic matter (OM) ≈ 2 wt.%) and DS-M (high plasticity, OM ≈ 18 wt.%)—treated with practical hydraulic road binder (HRB) dosages. This is the first French study that directly contrasts two different DS types under identical HRB treatment and proposes practical boundary thresholds. Physical indexes (particle size, methylene-blue value, Atterberg limits, OM) were measured; mixtures were compacted (Modified Proctor) and tested for immediate bearing index (IBI). IBI, unconfined compressive strength, indirect tensile strength, and elastic modulus were determined. DS-F reached IBI ≈ 90–125%, UCS ≈ 4.7–5.9 MPa, and ITS ≈ 0.40–0.47 MPa with only 6–8 wt.% HRB, satisfying LCPC-SETRA class S2–S3 requirements for road subgrades. DS-M never exceeded IBI ≈ 8%, despite 3 wt.% lime + 6 wt.% cement. A decision matrix distilled from these cases and recent literature shows that successful stabilization requires MBV < 3 g/100 g, plastic index < 25%, OM < 7 wt.%, and fine particles < 35%. These thresholds permit rapid screening of dredged lots before costly treatment. Highlighting both positive and negative evidence clarifies the realistic performance envelope of soil–cement reuse and supports circular-economy management of DS. Full article

Glass curators often question how their treatments affect the long-term stability of historical glass. While damp cotton swabs are commonly used to remove surface salts and dust, the use of water remains controversial, particularly for heavily altered glass, due to concerns about worsening hydration. This study investigates the effect of water rinsing on an unstable soda-lime glass altered for six months (monoliths) and fifteen months (powders) at 35 °C and 85% relative humidity. Samples were then rinsed with Milli-Q water at 20 °C or 50 °C, and the monolithic glass was subsequently subjected to an additional 15 months of alteration under the same conditions. The glass surface was characterized by optical and scanning electron microscopy (SEM) as well as Raman spectroscopy to identify the nature of the salts. The evolution of the hydrated layer was assessed using transmission FTIR, Raman and solid-state NMR spectroscopies, ToF-SIMS, and thermogravimetric analysis (TGA). The results show that rinsing effectively removes surface salts—primarily sodium carbonate—and induces structural changes in the hydrated layer, promoting silicate network polymerization. Upon resuming alteration, rinsed monolithic samples exhibit no further degradation after the additional 15 months of alteration. These findings offer promising insights for conservation practices and may help curators refining their treatment strategies for altered glass. Full article

During the construction of subgrade, the remolding water content w of lime–sand-stabilized clay usually varies in a wide range, leading to inconsistent effectiveness in strength enhancement. Until now, this aspect has not been investigated. In this study, an unconfined compression test and microscopic observation were carried out on clay and stabilized clay (adding 4% lime by mass and 50% sand by volume). The results show the following: (1) remolding water content w had a strong effect on the soil fabrics of pure clay and lime-stabilized clay. An increase in the w from the dry to wet side of optimum reduced matric suction, which diminished the aggregation effect among fine-grained particles in both clay and lime-stabilized clay. Correspondingly, fine-grained aggregate progressively disintegrated, and dispersed fine-grained particles increased. As a result, the w increment at w ≤ w_cha made the dispersed fine-grained particles successively fill the large pores between aggregates, densifying the soil fabric. In contrast, at w > w_cha, the ongoing disintegration of aggregate resulted in progressive structural weakening. Herein, w_cha was defined as the characteristic water content at which the soil fabric transitioned from structural densification to weakening. (2) The UCS of both pure clay and lime–sand-stabilized clay followed a bell-shaped pattern as the w increased, with w_cha acting as the turning point. For pure clay soils, the UCS increased with increasing w up to w_cha because of structural densification, but decreased beyond w_cha due to structural weakening. In lime–sand-stabilized clay, where a sand grain skeleton developed, the compression of lime-stabilized clay induced by the movement of sand grains during shearing activated its contribution to the overall strength. The compressive capacity of the lime-stabilized clay varied in a bell-shaped manner with w, and this trend was mirrored in the UCS of lime–sand-stabilized clay. (3) At a low w, the fact that the clay aggregate exhibited sand-like mechanical behavior reduced the effectiveness of incorporating sand and lime for enhancing the UCS. As the w increased at w ≤ w_cha, the breakdown of aggregates enlarged the distinction between pure clay and sand, resulting in a more pronounced improvement in the UCS with the addition of sand and lime. At w > w_cha, the lubrication effect occurring at the contact between sand grains diminished the interlocking between the sand grains. Consequently, the effectiveness of the UCS enhancement decreased. Full article

Interest in explainable machine learning has grown, particularly in healthcare, where transparency and trust are essential. We developed a semi-automated evaluation framework within a clinical decision support system (CDSS-EQCM) that integrates LIME and SHAP explanations with multi-criteria decision-making (TOPSIS and Borda count) to rank model interpretability. After two-phase preprocessing of 2934 COVID-19 patient records spanning four epidemic waves, we applied five classifiers (Random Forest, Decision Tree, Logistic Regression, k-NN, SVM). Five infectious disease physicians used a Streamlit interface to generate patient-specific explanations and rate models on accuracy, separability, stability, response time, understandability, and user experience. Random Forest combined with SHAP consistently achieved the highest rankings in Borda count. Clinicians reported reduced evaluation time, enhanced explanation clarity, and increased confidence in model outputs. These results demonstrate that CDSS-EQCM can effectively streamline interpretability assessment and support clinician decision-making in medical diagnostics. Future work will focus on deeper electronic medical record integration and interactive parameter tuning to further enhance real-time diagnostic support. Full article

Considering the increasing requirements for the recovery of different natural and industrial waste materials, the application of volcanic ash as an alternative sustainable binder to traditionally employed lime and cement is proposed for soil stabilization for geotechnical engineering purposes, thus providing a reduction in carbon emissions. Soil stabilization was performed on natural clays with very high swelling potential, i.e. those classified as inadequate for reuse as a building material for geotechnical purposes. A mineralogical and chemical characterization of raw materials was carried out prior to the performance of different geotechnical laboratory tests, i.e., testing Atterberg limits, compaction, swelling potential, compressibility and resistance parameters over naturally remolded clay and soil mixtures with different binders. The swelling potential was reduced with an increase in the amount of applied binder, necessitating the addition of 10, 20, and 30% of volcanic ash compared to 3% lime, 3% cement and 5% lime, respectively, for a similar reduction in swelling potential. An investigation of the resistance parameters for soil mixture specimens that provided a suitable reduction in swelling potential for their reuse was performed, and a comparison to the parameters of naturally remolded clay was made. Full article

The popularity of offshore wind farming is accelerating, and researchers are exploring the possibility of implementing offshore wind turbines across the Great Lakes. Offshore wind turbines operate using the same principles as regular wind turbines, but require complex foundation design to withstand high shear forces from waves. Extensive site characterization is necessary to effectively design detailed offshore wind turbine structures. High cost and time commitments, along with policy and societal considerations, have limited present research on offshore wind feasibility in the Great Lakes. This study focuses on wave impacts, assessing popular offshore wind farms and identifying monopile foundations as the optimal design for a hypothetical offshore wind farm in the lime bedrock of Lake Huron. RSPile is used to assess the stability of the proposed foundation design against deflection, bending, and rotation under average wave forces and extreme storm events. Ultimately, preliminary analysis recommends an 8 m diameter pipe embedded 30 m into the seabed to satisfy industry standards for offshore wind turbine foundation design. Full article

The lack of interpretability in AI-based intrusion detection systems poses a critical barrier to their adoption in forensic cybersecurity, which demands high levels of reliability and verifiable evidence. To address this challenge, the integration of explainable artificial intelligence (XAI) into forensic cybersecurity offers a powerful approach to enhancing transparency, trust, and legal defensibility in network intrusion detection. This study presents a comparative analysis of SHapley Additive exPlanations (SHAP) and Local Interpretable Model-Agnostic Explanations (LIME) applied to Extreme Gradient Boosting (XGBoost) and Attentive Interpretable Tabular Learning (TabNet), using the UNSW-NB15 dataset. XGBoost achieved 97.8% validation accuracy and outperformed TabNet in explanation stability and global coherence. In addition to classification performance, we evaluate the fidelity, consistency, and forensic relevance of the explanations. The results confirm the complementary strengths of SHAP and LIME, supporting their combined use in building transparent, auditable, and trustworthy AI systems in digital forensic applications. Full article

A lime–sand island–reef formation has a dual structure consisting of an overlying loose or weakly consolidated coral sand (CS) layer and an underlying reef limestone layer. The coral sand layer is the sole carrier of the underground freshwater lens in the lime–sand island–reef, and it differs in terms of its hydraulic properties from common terrigenous quartz sand (QS). This study investigated the mechanism of freshwater lens formation, dominated by solute dispersion, combining multi-scale experiments and numerical simulations (GMS) to reveal the control mechanisms behind the dispersion properties of coral sand and their role in freshwater lens formation. Firstly, the dispersion test and microscopic characterization revealed the key differences in coral sand in terms of its roundness, roughness, particle charge, and surface hydrophilicity. Accordingly, a hierarchical conversion model for the coral sand–quartz sand coefficient of dispersion (COD) was established (R² > 0.99). Further, combining this with numerical simulation in GMS revealed that the response pattern of the coefficient of dispersion to key parameters of freshwater lens development is as follows: freshwater appearance time > steady-state freshwater body thickness > steady-state freshwater reserve > lens stabilization time. These results clarify the development mechanism and formation process behind freshwater lenses on island reefs, from the micro to the macro scale, and provide a scientific basis for optimizing the protection of freshwater resources in coral islands and guiding the construction of artificial islands. Full article

International waste policy promotes the reduction and re-use of waste materials, and in some cases, specifically calls for the use of recycled materials in pavements. In countries like Australia, most of the aircraft pavement network is constructed of flexible pavements. Consequently, understanding the opportunities for recycled materials in flexible aircraft pavements is paramount to increasing the technology uptake. This paper reviews opportunities for the incorporation of recycled materials in flexible airport pavement construction, specifically, their application to particle substitution in unbound and asphaltic layers, use in stabilization treatments, and use as a bitumen modifier. Additionally, environmental product declarations are reviewed to provide a range of typical environmental costs for each recycled material when considering material processing for incorporation into flexible pavements. These materials are compared to virgin material environmental costs to determine which recycled materials provide the highest environmental benefit potential. It was concluded that particle replacement in unbound layers with waste materials had a similar environmental cost to using virgin materials. However, the requirement to dispose of waste material to the landfill can be significantly reduced. For asphaltic layers, recycled asphalt pavement as an asphalt mixture replacement, fly ash as a hydrated lime replacement, and waste plastic and crumbed rubber as a virgin polymer replacement all are effective in reducing the environmental cost. To further increase the technology uptake, a risk-based approach for the implementation of waste materials in airport flexible pavements is recommended, which considers performance testing, the depth of the pavement layer, and the pavement functional area. Full article

High-plasticity clay soils pose significant challenges in geotechnical engineering due to their poor mechanical properties, such as low strength and high compressibility. Lime–cement stabilization offers a sustainable solution, but optimizing additive proportions requires advanced analytical approaches to decipher complex soil-stabilizer interactions. This study investigates the stabilization of high-plasticity clay soil (CH) sourced from Kano, Nigeria, using lime (0–30%) and cement (0–8%) for thirty (30) sample combinations to optimize consolidation and strength properties. Geotechnical laboratory tests (consolidation and UCS) were evaluated per ASTM standards. Multivariate analysis integrated principal component analysis (PCA) with regression modeling (PCR) for sensitivity and causality assessment. Optimal stabilization (15% lime + 6% cement) significantly improved soil properties: void ratio reduced by 58% (0.60→0.25), porosity by 49.5% (0.38→0.19), UCS increased by 222.5% to 2670 kPa (28 days), preconsolidation stress by 206% (355.63→1088.92 kPa), and compressibility modulus by 16% (7048→10,474.28 kPa). PCR sensitivity analysis attributed 46% of UCS variance to PC1 (compressibility parameters: void ratio, porosity, compression index; β = 0.72). PCR Causality analysis shows improvment with curing (R²: 68.7% at 7 days→83.0% at 28 days; RMSE: 11.2→7.8 kPa). PCR establishes compressibility reduction as the dominant causal mechanism for strength gain, providing a robust framework for dosage optimization beyond empirical approaches. Full article

Renewable energy, especially wind power, is required to reduce greenhouse gas emissions and fossil fuel use. Variable wind patterns and weather make wind energy integration into modern grids difficult. Energy trading, resource planning, and grid stability demand accurate forecasting. This study proposes a hybrid deep learning framework that improves forecasting accuracy and interpretability by combining advanced deep learning (DL) architectures, explainable artificial intelligence (XAI), and metaheuristic optimization. The intricate temporal relationships in wind speed data were captured by training Long Short-Term Memory (LSTM), Gated Recurrent Unit (GRU), LSTM-GRU hybrid, and Bidirectional LSTM-GRU following data preprocessing and normalization. To enhance transparency, Local Interpretable Model-Agnostic Explanations (LIMEs) were applied, revealing key time-step contributions across three urban datasets (Los Angeles, San Francisco, and San Diego). The framework further incorporates the Snake Optimizer Algorithm (SOA) to optimize hyperparameters such as LSTM units, dropout rate, learning rate, and batch size, ensuring improved training efficiency and reduced forecast error. The model predicted 2020–2040 wind speeds using rolling forecasting; the SOA-optimized LSTM model outperformed baseline and hybrid models, achieving low MSE, RMSE, and MAE and high R² scores. This proves its accuracy, stability, and adaptability across climates, supporting wind energy prediction and sustainable energy planning. Full article