Physics and Chemistry of the Earth最新文献

{"title":"From policy to practice: Evaluating gender mainstreaming in Namibia's water sector","authors":"Rennie Munyayi ,&nbsp;Benjamin Mapani ,&nbsp;Rosemary Shikangalah","doi":"10.1016/j.pce.2026.104287","DOIUrl":"10.1016/j.pce.2026.104287","url":null,"abstract":"<div><div>The Southern African Development Community (SADC) Member States adopted regional gender instruments that set targets for gender equality and were subsequently domesticated through national policies, including Namibia's National Gender Policy (2010–2020). This study examines the extent to which the Department of Water Affairs (within the Ministry of Agriculture, Water and Land Reform at the time of study) has translated formal gender equality commitments into substantive gender mainstreaming practices beyond policy rhetoric. Using a mixed-methods design, we combined document review with an online survey adapted from the International Labour Organisation gender audit framework. Forty-nine staff members responded (32 % response rate). Results indicate persistent institutional constraints: 87.8 % of respondents reported no formal training on gender equality in policy or programming, while confidence to perform core gender mainstreaming functions remained very low (2–5 %), alongside high non-response across proficiency items. Institutional support mechanisms were weak, with 89.8 % reporting no periodic support from gender focal points. At sector level, Namibia's AMCOW WASSMO Indicator 6.6 score declined from 44 % (2019) to 33 % (2024), suggesting that earlier policy-alignment gains were not sustained. Document review further identified no explicit budget allocations for gender mainstreaming within reviewed annual budgets (2018–2022), indicating limited fiscal institutionalisation. Interpreted through Gender and Development and institutional theory, the findings point to structural decoupling, weak incentives, and limited systematic embedding of gender requirements in planning, budgeting, monitoring, and programme design. We recommend establishing a dedicated gender mainstreaming unit, instituting gender responsive budgeting with tracked allocations, and strengthening applied capacity through mandatory training linked to performance and reporting. Further research should examine accountability architectures that can accelerate measurable gender outcomes across the SADC water sector.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104287"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial distribution and ecological risk evaluation of microplastics in surface water, sediment, and Oreochromis niloticus from the Eravur sector, Batticaloa Lagoon, Sri Lanka","authors":"A.S. Samrooth Jahan ,&nbsp;J.M. Harris ,&nbsp;M.H. Haroon ,&nbsp;Sabiqah Tuan Anuar ,&nbsp;Jose Hernandez Santos ,&nbsp;Chingakham Chinglenthoiba","doi":"10.1016/j.pce.2025.104260","DOIUrl":"10.1016/j.pce.2025.104260","url":null,"abstract":"<div><div>Batticaloa Lagoon is a major and prominent coastal ecosystem in Sri Lanka. However, increasing anthropogenic activities around the Eravur sector have raised the plastic accumulation thus lead to concern of microplastic contamination and ecological risk. Therefore, this study intends to examine the abundance, spatial distribution and compositional characterization of microplastics in three separate aquatic environmental components such as surface water, sediment, and <em>Oreochromis niloticus</em> at the Eravur lagoon. Total microplastic abundance in surface water and sediment was 512.25, 412.33 ± 19.90 items L⁻¹ and ±29.26 items Kg⁻¹dry weight respectively with significantly higher concentrations at those sites located at lagoon shore (267.6 ± 15.4 items L⁻¹; 329.9 ± 22.3 items Kg-1) than lagoon sample sites (ANOVA, p &lt; 0.001). Sediments had a greater proportion of microplastics (∼55 %) than surface waters, made of fragments and films, mostly white and transparent particles, and the smaller size fractions occupy the largest contributions to total counts (&lt;1-2 mm-1-2mm: 30–34 %) in sediments; While in surface waters (2–4 mm: 41 %). Microplastics were found in 26 of 30 individuals of the <em>O. niloticu</em>s (232 particles; 7.73 ± 6.8 ind⁻¹), dominated by filaments (∼69 %), mostly &lt;1 mm (∼62 %), and ingestion was positively correlated with fish weight and length (r = 0.799 and r = 0.793, respectively; p &lt; 0.001). FTIR confirms seven major polymer types where PET was most abundant in sediment (26 %), PS in surface water (30 %) and PE and PP in fish samples (25 % each). The evidence of active microplastic transfer shows significant impacts on lagoon ecology.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104260"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174647","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting the Urban heat and pollution Islands over the Kolkata metropolitan area, India","authors":"Pragya Pandey ,&nbsp;Bhishma Tyagi ,&nbsp;Pradeep Kumar ,&nbsp;Saroj Kumar Sahu ,&nbsp;Kuldeep Sharma","doi":"10.1016/j.pce.2026.104330","DOIUrl":"10.1016/j.pce.2026.104330","url":null,"abstract":"<div><div>Urban environments alter local climate and air quality through concentrated emissions of heat and pollutants, giving rise to effects such as Urban Heat Island (UHI) and Urban Pollution Island (UPI). These microclimatic phenomena have seen growth due to industrialisation and urbanisation. Their coupled interaction in the context of Indian cities, however, remains poorly understood. In this study, we have investigated the evolution of UHI and UPI over a megacity of India, Kolkata, with a focus on Kolkata Metropolitan Area (KMA) by analysing Remote Sensing (MODIS) and in situ measurements (CPCB) of Land Surface Temperature (LST), UHI, Aerosol Optical Depth (AOD), Direct and Diffuse Solar Radiation, and Particulate Matter (PM_2.5 and PM₁₀) for a collective period of 2001–2024. UHI and UPI were observed over KMA, with both Nighttime LST (NLST) and Daytime LST (DLST) as well as AOD having significantly higher values over the urban region by +1.79 °C, +2.92 °C, and 0.18, respectively, than in rural areas. The results also suggested that the magnitudes of UHI and UPI are increasing over the years for KMA. As a result of increasing UPI, the study observed a simultaneous reduction of direct solar radiation by 22.64 W/m² and an increase of diffuse radiation by 18.82 W/m² over urban areas for the study period. The study suggests that the UPI and UHI may influence each other through direct and diffuse radiative forcing, and that the modulation of urban surface energy balance may occur due to these changes, which may be a link to unprecedented weather events over the region. The results provide a scientific basis for developing policies on regional climate adaptation and air quality management in Indian cities.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104330"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Designing landslide mitigation strategies through developing knowledge aware deep learning model integrated explainable artificial intelligence","authors":"Inzamam Ul Haq ,&nbsp;Habibullah ,&nbsp;Shafiq Ahmed ,&nbsp;Swapan Talukdar ,&nbsp;Mansoor Ahmad ,&nbsp;Md Sarfaraz Asgher ,&nbsp;Imran Khan ,&nbsp;G.V. Ramana","doi":"10.1016/j.pce.2025.104266","DOIUrl":"10.1016/j.pce.2025.104266","url":null,"abstract":"<div><div>Landslides are a recurrent and damaging hazard in the Pir Panjal Range of Jammu and Kashmir, India, where steep slopes, fragile lithology and rapid human interventions coincide. This study develops an integrated landslide susceptibility mapping framework that combines machine learning (ML), deep learning (DL) and explainable artificial intelligence (XAI) to support risk-informed planning. An inventory of 1105 landslides and eighteen conditioning factors trains four ML models: Random Forest (RF), Support Vector Machine (SVM), Gradient Boosting Machine (GBM) and Categorical Boosting (CatBoost), evaluated with five-fold stratified cross-validation and a held-out test set. In parallel, a Bayesian-optimised DL model, in which a Variational Autoencoder (VAE) learns latent features that are classified by a Multilayer Perceptron (MLP), captures complex non-linear controls on slope failure. The best performing models achieve an area under the receiver operating characteristic curve (AUC-ROC) of about 0.96 and overall accuracy close to 0.90 on validation data, indicating high discriminatory skill. Spatially, High and Very High susceptibility zones together occupy roughly one quarter of the range and are concentrated in tehsils such as Gool Gulabgarh, Ramban, Thathri and Banihal, which emerge as hotspots for intervention. XAI diagnostics highlight vegetation condition, monsoon rainfall, lineament density and drainage density as dominant controls on susceptibility, while counterfactual experiments show that realistic improvements in vegetation cover, surface drainage and slope management can shift many locations from high to lower risk classes. The framework therefore provides accurate, interpretable and useful susceptibility maps for land-use regulation, infrastructure planning and landslide mitigation in data-constrained mountain environments.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104266"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146015539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design and development of catalytic converter for diesel engines using phase change materials","authors":"R.K. Tyagi,&nbsp;Yash Saksena","doi":"10.1016/j.pce.2026.104289","DOIUrl":"10.1016/j.pce.2026.104289","url":null,"abstract":"<div><div>An exhaust system is a discharge control mechanism for vehicles that transforms the fumes from an ignition motor's burning byproducts into less hazardous compounds through catalyzed compound reactions. To reduce emissions, aluminum oxide and chromium oxide are used in the catalytic converter analysis for the minimization of emissions as much as possible. Polyurethane has been used as a phase change material which plays a pivotal role in adsorbing the heat for a prolonged period and then releasing it which enhances the fuel efficiency of the vehicle, increases the life cycle of the vehicle and increases its life cycle for a prolonged period. The analysis also aims to determine the impact of the catalytic converter on emissions. The test engine, catalytic converter, AVL exhaust fuel analyzer, temperature gun and other measurement devices make up the experimental setup. The test engine was a four-stroke diesel single-cylinder engine. Initially, the engine was running with the existing catalytic converter with no other addition, and the emissions have been analyzed using gas analyzer of AVL. The exhaust emissions, and the design of the catalytic converter were considered as a main challenge where it was observed that heat was being adsorbed and emissions were reduced to around 30-40% in every case possible and oxygen, lambda value increased by 15-20 % where these test were examined under no load conditions of the engine where welding of catalysts and PCM played an important role for enhancement of the catalytic converter. Under identical engine rotational conditions, the catalytic converter equipped with phase change material achieved significant reductions in hydrocarbon emissions (63%), intake air temperature (48%), NO_x (24%), and CO (60%).This catalytic converter can further reduce the knocking possibilities of the engine in the harsh weather conditions as diesel engines possess cluster combustion and constant heat adsorption can enhance the life cycle of the engine which is one of the major finding from this experiment.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104289"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174639","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on the performance and mechanism of ammonia nitrogen and phosphorus removal in bioretention facilities enhanced by aluminum-based P-inactivation agent","authors":"Jing Li ,&nbsp;Wenhua Chen ,&nbsp;Shuai Yuan ,&nbsp;Weihang Cai ,&nbsp;Hua Yang ,&nbsp;Fei Li ,&nbsp;Wei Cao ,&nbsp;Shupo Liu ,&nbsp;Zhenming Zhou","doi":"10.1016/j.pce.2026.104311","DOIUrl":"10.1016/j.pce.2026.104311","url":null,"abstract":"<div><div>Bioretention facilities are widely utilized in sponge city infrastructure; however, conventional substrate fillers exhibit limited efficiency in removing nitrogen (N) and phosphorus (P). This limitation necessitates the selection of high-performance active fillers to enhance the N and P removal capabilities of bioretention facilities. This study compared the ammonia nitrogen (NH₄⁺-N) and P removal performance of four substrate fillers—bio-ceramsite, volcanic rock, quartz sand, and aluminum-based P-inactivation agent (Al-PIA)—to identify the optimal substrate filler. Under high pollutant loading conditions, the optimal thickness of the selected filler for NH₄⁺-N and P removal was determined. The NH₄⁺-N and P removal performance of bioretention facilities utilizing Al-PIA was then evaluated under low and high pollutant load concentrations, and the effects of the drying period on NH₄⁺-N and P removal were assessed. Additionally, the P removal mechanisms of Al-PIA, as well as the N and P removal pathways in the bioretention facility, were elucidated. Results indicated no significant difference in NH₄⁺-N removal among the four fillers (P &gt; 0.05). However, the Al-PIA exhibited the highest total phosphorus (TP) removal, with a mean removal efficiency of 72.46 %, establishing it as the optimal filler. The most effective Al-PIA layer thickness was 12 cm, achieving mean removal efficiencies of 84.67 % for NH₄⁺-N and 95.35 % for TP. Under various pollution load concentrations, the effluent NH₄⁺-N and TP concentrations from bioretention facilities utilizing Al-PIA complied with China's Class IV surface water standards, and demonstrate excellent NH₄⁺-N and P removal stability and interference resistance under varying drying periods. P removal by Al-PIA was primarily governed by physical adsorption, electrostatic attraction, surface precipitation, and ligand exchange. In the bioretention facility, N removal was facilitated by physical adsorption in the planting soil, plant uptake, adsorption by Al-PIA, and subsequent microbial nitrification. The removal of P was mainly attributed to adsorption by Al-PIA (87.40 %) and plant uptake and assimilation (10.40 %).</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104311"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146081174","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microplastics in the environment: Sources, impacts, degradation strategies and energy recovery options-A rigorous review","authors":"J. Aravind Kumar ,&nbsp;A. Annam Renita ,&nbsp;S. Sathish ,&nbsp;D. Prabu ,&nbsp;Ashwin Jacob ,&nbsp;Ahmad Hosseini-Bandegharaei ,&nbsp;M. Kavisri ,&nbsp;Meivelu Moovendhan","doi":"10.1016/j.pce.2026.104323","DOIUrl":"10.1016/j.pce.2026.104323","url":null,"abstract":"<div><div>Microplastics, pervasive in the environment, have emanated as a pressing environmental implication due to their widespread dispersal and potential adverse effects on ecosystems and human health. This comprehensive review succumbs an in-depth scrutiny of microplastics, encompassing their sources, distributions, and environmental impacts. Sources of microplastics encompass a wide array of industrial and household activities, ranging from daily care products to the food industry and common household items. In addition, algae play a key part in the degrading processes that microplastics undergo, with macro- and microalgae being major players in remediation initiatives. To understand the flowing ecological effects, the complex relationships that microplastics have with marine organisms, especially those that are part of the marine food web are examined. Furthermore, cutting-edge process technologies like anaerobic digestion, hydrothermal liquefaction (HTL), and thermal hydrolysis process (THP) present viable paths for managing microplastics, with a focus on energy recovery via co-digestion procedures. The review additionally presents potential directives for forthcoming research, highlighting the necessity of continuing efforts to maximize cleanup tactics, lessen environmental effects, and protect ecosystems around the world from the increasingly dangerous threat of microplastic pollution. Biodegradation strategies for disintegrating such microplastic were also highlighted and explored at the outset.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104323"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"DOC-governed metal solubility and mobility in river sediments: Integrating machine learning, causal pathways, and geochemical simulations","authors":"Fahmida Sultana ,&nbsp;Zia Ahmed ,&nbsp;Fei Zhang ,&nbsp;Tasrina R. Choudhury ,&nbsp;M. Safiur Rahman","doi":"10.1016/j.pce.2026.104322","DOIUrl":"10.1016/j.pce.2026.104322","url":null,"abstract":"<div><div>This study explores the complex interactions between sediment texture, dissolved organic carbon (DOC) levels, and water chemistry in influencing the solubility and mobility of toxic metals (Cd, Ni, Zn, Cu, Cr, Pb) in river sediments. A multi-tiered approach integrating machine learning, Structural Equation Modeling (SEM), and geochemical simulations was employed to understand metal behavior in the Meghna River, Bangladesh. Redundancy Analysis (RDA) revealed that sediment texture and DOC fractions are the primary drivers of metal mobility, with clay content contributing the most to variation in metal concentrations (Variance Inflation Factor (VIF) values for clay = 3.50). The study employed Random Forest (RF) and XGBoost models to predict metal concentrations, achieving exceptional predictive accuracy with Area Under the Curve (AUC) values of 1.000 for Ni, Zn, Cr, and Pb, and 0.964 for Cd. Regression models demonstrated strong performance with R² values of 0.963 for Pb, 0.938 for Ni, and 0.928 for Zn, highlighting the robustness of DOC and sediment texture in explaining metal variability. SEM analysis indicated that pH mediates the DOC–metal relationship, with standardized path coefficients for DOC retention and metal mobility being −0.475 and 0.96 for Zn, respectively. The GIS-based Metal Mobility Index (MMI) and Soil Mobility Index (SMI) predicted high-risk zones for metal mobility, with an AUC of 0.91, effectively distinguishing between high and low mobility regions. These findings provide critical insights into metal transport dynamics and offer valuable tools for river sediment management and metal contamination risk assessment.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104322"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geotechnical and microstructural assessment of gas condensate–contaminated clayey gravel","authors":"Amin Falamaki ,&nbsp;Abdosalam Dashti ,&nbsp;Aghileh Khajeh ,&nbsp;Amir Hossein Vakili ,&nbsp;Amir Hossein Karimi","doi":"10.1016/j.pce.2026.104340","DOIUrl":"10.1016/j.pce.2026.104340","url":null,"abstract":"<div><div>This study investigates the detrimental effects of gas condensate contamination on the geotechnical properties of clayey gravel (GC) soil, addressing a pressing environmental and geotechnical engineering challenge. Soil samples were systematically contaminated with gas condensate at concentrations of 0, 2, 4, 6, and 8% by dry weight and subjected to comprehensive geotechnical testing, including Atterberg limits, modified Proctor compaction, direct shear, unconfined compressive strength (<em>UCS</em>), and California bearing ratio (<em>CBR</em>). Testing of Atterberg limits revealed progressive reductions in soil consistency, with the liquid limit decreasing by 15.2% (from 30.9% to 26.2%) and the plastic limit by 13.5% (from 21.0% to 18.16%) at maximum contamination. Modified Proctor compaction tests identified a critical threshold at 4% contamination, where maximum dry density initially increased by 1.2% before declining by 4.5% at higher concentrations, while optimum moisture content decreased by 28.6%. Strength characterization showed severe degradation, with <em>UCS</em> experiencing a 68.8% reduction (from 938.49 to 293.07 kPa) and <em>CBR</em> values decreasing by 52.3% at 100% relative density. Direct shear tests demonstrated substantial weakening of shear strength parameters, with cohesion declining by 53% and friction angle by 25%. These findings underscore the severe implications of gas condensate contamination for soil stability and highlight the urgency of implementing mitigation measures to safeguard infrastructure and environmental integrity at gas condensate storage sites.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104340"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174277","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of lime treatment on the microstructure and geotechnical properties of micaceous soil","authors":"Amaranatha Ginkapalli Anjaneyappa ,&nbsp;Seelam Srikanth ,&nbsp;Subhashish Dey","doi":"10.1016/j.pce.2026.104324","DOIUrl":"10.1016/j.pce.2026.104324","url":null,"abstract":"<div><div>Micaceous soils present significant challenges in geotechnical engineering due to their platy mineral structure, high compressibility and poor load-bearing capacity. The untreated soil examined in this study contained a high fraction of flaky mica and exhibited inherently weak engineering behavior, with an unconfined compressive strength (UCS) of approximately 45 kPa and low bearing resistance, rendering it unsuitable for direct use in pavement and embankment applications. Although the lime stabilization is widely adopted for improving fine-grained soils, its effectiveness and underlying mechanisms in mica-rich soils remain inadequately understood, particularly the relationship between micro-structural evolution and engineering performance. To address this gap, the present study systematically evaluates the influence of lime treatment on the mechanical and micro-structural behavior of micaceous soil. Soil samples were treated with 2%, 4%, 6% and 8% quicklime and cured for periods of up to 56 days, followed by evaluation of strength, compaction characteristics, consistency limits and micro-structural characteristics. The UCS increased substantially, reaching a peak value of 244.8 kPa at 4% lime after 56 days, representing an improvement of approximately 5.4 times compared to the untreated soil. The California Bearing Ratio (CBR) also peaked at the same lime dosage, with unsoaked CBR increasing from 3.65% to 9.34% and soaked CBR from 2.12% to 7.15%. Micro-structural analyses using SEM, EDS, XRD and FTIR revealed the formation of cementitious products, particularly calcium silicate hydrate (C–S–H) and calcium aluminates hydrate (C-A-H) phases, providing mechanistic insight into the observed strength improvements. The added value of this study lies in explicitly linking micro-structural transformations to macroscopic strength and bearing enhancement in lime stabilized micaceous soils, demonstrating that lime treatment can effectively upgrade problematic mica-rich soils to meet the engineering requirements for pavement sub-grades and embankment fills.</div></div>","PeriodicalId":54616,"journal":{"name":"Physics and Chemistry of the Earth","volume":"143 ","pages":"Article 104324"},"PeriodicalIF":4.1,"publicationDate":"2026-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146174273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}