Search Results (1,699)

Water-soil gushing caused by tunnel leakage can induce severe ground disturbance and threaten the safety of shield tunnels, yet rapid prediction remains difficult because high-fidelity numerical simulations are computationally expensive. This study develops an interpretable machine-learning framework for predicting gushing-induced ground disturbance around shield tunnels based on a validated two-phase Material Point Method database. Six governing variables are considered, including the tunnel depth ratio, gushing location, soil friction angle, Young’s modulus, intrinsic permeability, and soil gushing mass. Three representative response variables were selected, namely the maximum ground settlement, flow-zone width, and flow-zone centroid angle. Five algorithms, including MLP, RF, XGBoost, SVR, and Ridge, were established and compared, with hyperparameters optimised using Optuna. The results show that nonlinear models consistently outperform the linear baseline, among which MLP, RF, and XGBoost achieve the best overall accuracy and robustness. Error-distribution analysis further indicates that MLP and RF yield the highest proportion of low-error predictions. SHAP interpretation shows that SGM is the dominant factor governing maximum settlement and flow-zone width, whereas gushing location primarily controls the flow-zone centroid angle. The proposed framework provides an efficient and physically interpretable surrogate for rapid hazard assessment of gushing-induced ground disturbance in shield tunnelling. Full article

The scarcity of natural aggregates and the accumulation of oil sludge in desert regions pose critical challenges for highway construction. Although aeolian sand and oil sludge pyrolysis residue have been studied individually as construction materials, their combined use in foamed lightweight soil remains unexplored. This study addresses this gap by developing a novel foamed lightweight soil termed SOFS, which is created through the synergistic modification of aeolian sand and oil sludge pyrolysis residue. A six-factor, five-level orthogonal array (L25) was employed to systematically investigate the effects of residue content, sand content, foam-to-slurry ratio, foaming agent dilution, water-to-solid ratio, and mixing time. The evaluated properties included physical properties (fluidity and wet density), mechanical properties (compressive, splitting tensile, and flexural strength), and durability (wet–dry and freeze–thaw resistance). Scanning electron microscopy was used to examine the microstructural mechanisms. Variance and range analysis identified the optimal mixture, designated H14, which achieved 28-day compressive, splitting tensile, and flexural strengths of 3.75 MPa, 2.21 MPa, and 0.9 MPa, respectively, thereby meeting desert roadbed requirements. Compared with conventional materials, H14 exhibited superior durability, with strength losses of only 16.3% in compressive strength and 19.1% in splitting tensile strength after 25 cycles. Microstructural analysis revealed a dense C-S-H gel network encapsulating the solid waste particles, with nanoscale Al- and Cl-rich crystalline phases observed at interfacial pores—a phenomenon that has rarely been documented in previous studies. These findings provide a theoretical and technical foundation for solid waste valorization and the development of sustainable desert infrastructure. Full article

Soil water retention capacity (SWRC) is vital for agriculture and watersheds, but traditional measurements are hindered by destructive sampling and spatial discontinuity. This study selected Youyi and Heshan farm in Heilongjiang Province as the study area, using the time-series Normalized Difference Water Index (NDWI) from Sentinel-2 during the snowmelt-to-bare-soil window as a soil water retention signature (SWRS) for monitoring SWRC. The exponential decay fitting model (EDFM) was used to construct a Soil Moisture Decay Index (SMDI) to analyze the spatial patterns of the SWRC. Results showed that: (1) time-series NDWI exhibited distinct exponential decay signatures varying with soil textures and degradation gradients; (2) the EDFM effectively fitted the time-series NDWI (R² = 0.84–0.99), extracting decay rate and stable level to quantify SWRC; (3) SMDI showed high consistency with in situ soil moisture (R = 0.82–0.88) and measured field capacity (Youyi Farm: R² = 0.56; Heshan Farm: R² = 0.59), and correlated significantly with soil organic matter (R² = 0.61–0.71) and texture (R² =0.50–0.64), confirming the physical controls on water retention; and (4) SMDI spatial distribution revealed distinct degradation patterns across varying topographic and soil conditions. This study innovatively transformed point-scale static SWRC measurements into spatially continuous monitoring, offering new tools for precision water management and degraded-soil restoration, with strong theoretical and practical value. Full article

Tunnel seepage in heterogeneous ground can trigger hydrogeological hazards such as concentrated water inflow, groundwater depletion, deformation of surrounding structures, and subsequent eco-environmental degradation. However, these processes are still commonly evaluated using deterministic models that neglect the spatial variability of hydrogeological parameters. To address this limitation, this study develops a stochastic hydro–geo–mechanical–ecological framework that integrates random field theory with physics-informed neural networks (PINNs) for hazard evaluation and rapid prediction of tunnel seepage responses. The spatial variability of key parameters, including permeability and porosity, is characterized using the Karhunen–Loeve expansion and embedded into coupled governing equations for unsaturated–saturated seepage, seepage–stress interaction, and groundwater–soil–vegetation responses. A PINN surrogate model with random-field inputs is then constructed to predict hydraulic head, tunnel inflow, displacement, groundwater depth, vegetation coverage, and soil physicochemical indices, while simultaneously quantifying uncertainty. A karst tunnel case in Chongqing, China, is used to demonstrate the proposed framework. The results show that spatial heterogeneity promotes preferential flow paths and intensifies seepage-induced hazards compared with deterministic mean simulations, leading to larger groundwater drawdown, stronger ecological degradation, and greater overall response variability. The proposed PINN achieves high predictive accuracy (R² > 0.97) and reduces single-case computational time from hours to seconds, enabling efficient multi-scenario evaluation and uncertainty-aware risk assessment. This framework provides a physically consistent and computationally efficient tool for evaluating water-related hazards and long-term environmental impacts in underground engineering. Full article

Soil erosion is a critical environmental issue restricting ecological security and agricultural sustainable development in China. Traditional studies have predominantly focused on physical driving factors such as hydraulic and wind erosion, while the regulatory effects of hydrochemistry on soil erosion have long been neglected. To clarify the mechanisms and regulatory processes of hydrochemistry-driven soil erosion in China, this study collected 795 relevant publications from the Web of Science Core Collection spanning from 2000 to 2025. Based on bibliometric methods, visualization software including VOSviewer 1.6.20 and CiteSpace 6.4.R1 were adopted to analyze publication trends, author distributions, research institutions, and keyword co-occurrence characteristics. The results indicated that the number of publications concerning hydrochemistry-driven soil erosion in China has increased year by year since 2000. China ranks first in total publication output, showing a dominant research position in this field. The Chinese Academy of Sciences contributed the largest number of publications among all research institutions. Keyword co-occurrence analysis over the past 25 years demonstrated that soil erosion, runoff, and water erosion serve as the core research hotspots. Further analysis revealed the regulatory mechanisms of key hydrochemical parameters (e.g., pH value, ionic strength, and dissolved organic carbon) throughout erosion processes. In-depth keyword analysis confirmed that current research on hydrochemistry-driven soil erosion in China remains at the preliminary stage, lacking comprehensive exploration of microcosmic mechanisms and systematic regulation strategies. Therefore, intensified research efforts and optimized regulatory frameworks are urgently required in future studies. This study can provide theoretical foundations and technical references for improving the understanding of erosion driving mechanisms and enhancing soil erosion management efficiency across diverse regions of China. Full article

Modeling the unsaturated soil hydraulic conductivity function (SHCF) is essential for understanding water movement in unsaturated zones and supporting effective agricultural and environmental management. Accurate estimation of SHCF parameters, particularly the α and n parameters of the van Genuchten–Mualem (VGM) model, remains a challenging endeavor due to the complex interplay of soil physical properties. Tree-based machine learning methods have shown promising capabilities in this area. To further assess and compare the performance of tree-based approaches, this study aimed to evaluate the efficiency of three algorithms, Cubist, RF, and light gradient boosting machine (LightGBM), in the parametric estimation of SHCF using 196 soil samples from the UNSODA database. Input variables, including sand, clay, soil bulk density (BD), field capacity (FC), and permanent wilting point (PWP), were structured into four progressively complex pedotransfer functions (PTFs). Results indicate that Cubist demonstrated the best overall generalization during testing, achieving the lowest average RMSD (7.165) across the four PTFs compared to RF (7.602) and LightGBM (8.068), although RF and LightGBM achieved marginally better performance on individual PTF-metric combinations. All three algorithms achieved high coefficients of determination (R² ≥ 0.95) across all PTFs. Specifically, in PTF4, the best-performing model, Cubist achieved a 6.8% lower RMSD than RF and a 12.4% improvement over LightGBM. Shapley additive explanations (SHAP) conducted via XGBoost surrogate models, suggested that FC and PWP were the most influential predictors of SHCF among the variables examined. These findings suggest that Cubist is a viable approach for estimating SHCF, particularly when input data are limited to basic soil properties. Full article

Salt stress remains a major global stress factor among abiotic stresses limiting crop production. Salt stress is a major nutritional challenge, with poor agricultural production characterized by high soil sodium (Na⁺) levels in soil and plants. Soil salinity negatively affects plants through both osmotic effects and ionic toxicity. Hence, one of the main aims of agricultural scientists is to develop eco-friendly, sustainable solutions to alleviate soil salinity. Over the past decades, several studies have recommended biochar as a vital sustainable soil amendment to alleviate the negative consequences of soil salinity. Thus, this review builds on the literature on biochar-mediated alleviation of salt stress. Biochar is a carbon-rich material produced from biomass and feedstock via pyrolysis under little or no oxygen conditions. Due to its unique characteristics, such as high carbon, high surface area with porous and aromatic structure, high pH, high stability, cation exchange capacity, and water and nutrient retention capacity, it is considered an alternative for salt stress alleviation. Moreover, biochar facilitates sodium ion (Na⁺) adsorption, reduces Na⁺ uptake, and increases potassium ion (K⁺) uptake, enhancing nutrient cycling, helping plants maintain ionic balance and osmotic regulation. This, in turn, significantly increased the activity and diversity of soil microorganisms, enhanced their adhesion, and promoted their growth, thereby strengthening the plant’s salt resistance. Moreover, biochar-mediated improvements in microbial community dynamics and changes in the physical and biological properties of soil contribute to overall plant and soil health under salt stress. Hence, the present review aims to decipher the holistic patterns of biochar on soil and plant health, changes in physiological and defense mechanisms, plant hormones and signaling mechanisms, and the status of modified biochar under salt stress. Thus, the present review will pave the way for the production of salt-resilient crops with enhanced salinity tolerance. In conclusion, the use of biochar-based fertilizers and modified biochar enhanced microbial community dynamics in soil health homeostasis and soil fertility for agricultural production and food security. Full article

Submarine landslides pose severe marine geological hazards. Their movement and deposition behaviors can seriously threaten marine engineering stability and coastal safety. The propagation characteristics of landslide-generated tsunamis are therefore critical for hazard assessment. Physical model experiments provide an effective approach for investigating the underlying mechanisms of tsunami generation and propagation. To investigate the complete process from landslide motion to wave generation and propagation, this study developed an underwater soil-movement physical model test system. The system integrates controllable landslide initiation, real-time monitoring of landslide motion, wave height measurements, and full-field image acquisition, enabling synchronous observation of landslide movement and water body response. By controlling the main variables influencing submarine landslide dynamics, a series of physical model experiments were conducted to investigate water surface waves generated under different test conditions. The study examines the complete process from the initial water disturbance caused by submerged landslide motion to tsunami generation and propagation. The effects of landslide volume, particle size, initial submergence depth, and slope angle on tsunami parameters, including wave height, wave velocity, and wave period, were evaluated. Using 21 experimental datasets for each landslide type, namely, cohesionless sandy slides and muddy debris flows, empirical formulas for maximum surge height were established through dimensional analysis, SPSS (v25)-based multiple nonlinear regression, and validation against experimental results. The validation results show strong agreement between the empirical predictions and the physical model test data. Full article

The long-term effects of agricultural management systems (AMS) on soil physical properties and water infiltration in tropical Ferralsols remain incompletely understood. We assessed steady-state infiltration rates and soil physical properties in a Ferralsol after 20 years under five AMS in a Cerrado–Atlantic Forest transition area in Brazil: no-tillage (NT), conventional tillage (CT), integrated crop–livestock in crop (CL-C) and livestock (CL-L) phases, and permanent pasture (PP). Soil samples were collected at four depths, and infiltration was measured using the InfiAsper simulator at 60 mm h⁻¹. Integrated systems showed the best topsoil (0–0.05 m) physical condition, with higher macroporosity, aggregate stability, and organic carbon than NT and CT. Surface bulk density under PP was similar to integrated systems; higher bulk density values were observed under NT and CT at 0.10–0.20 m. Steady-state infiltration rates ranged from 26.40 mm h⁻¹ (PP) to 54.32 mm h⁻¹ (NT), with integrated systems averaging 59% higher than PP. Total SOC stocks (0–0.40 m) were significantly greater under CL-L (92.7 Mg C ha⁻¹) and CL-C (88.1 Mg C ha⁻¹) than PP (73.5 Mg C ha⁻¹; p = 0.004), driven by higher subsoil SOC concentrations under integrated systems; the lower subsoil bulk density under PP partially attenuated its calculated stock. These results demonstrate that integrated crop–livestock systems simultaneously improve soil physical condition, water infiltration, and carbon accumulation per unit land area, supporting sustainable intensification in the Brazilian Cerrado and Atlantic Forest biomes. Full article

Cadmium (Cd) contamination in agricultural soils poses serious risks to ecosystem health and food safety, highlighting the urgent need for efficient and environmentally stable immobilization materials. In this study, sodium alginate-based rectorite microspheres (REC beads) and triethylenetetramine-modified rectorite microspheres (TETA-REC beads) were fabricated and applied for the immobilization of Cd(II) in contaminated soils. Structural characterization confirmed that the ionic cross-linking encapsulation process preserved the layered structure of rectorite, while TETA modification introduced abundant amino functional groups that enhanced the interaction between the material and Cd(II). Immobilization experiments demonstrated that both microspheres exhibited rapid and stable Cd(II) passivation performance, with TETA-REC beads showing significantly higher efficiency. The maximum removal efficiencies of water-soluble and available Cd(II) reached 83.87% and 93.33%, respectively. Sequential extraction analysis revealed that the microspheres effectively transformed labile Cd fractions, including exchangeable and water-soluble forms, into more stable species. Mechanistic investigations indicated that Cd immobilization was governed by a synergistic combination of interlayer ion exchange, physical adsorption within the porous alginate structure, and coordination complexation between Cd(II) and amino groups introduced by TETA. Furthermore, microbial community analysis showed that the remediation process promoted the recovery of soil microbial diversity and metabolic functions. The developed TETA-REC microspheres provide a promising strategy for the efficient immobilization of Cd in contaminated soils and offer potential for the sustainable remediation of heavy metal-polluted farmland. Full article

In southern Brazil, a large proportion of farmers maintain their fields under fallow conditions during the transition period between summer and winter crops. During this interval, mechanical practices such as chiseling or the introduction of cover crop species may contribute to improving soil management and conservation in no-tillage systems. Therefore, this study aimed to investigate the effects of mechanical soil chiseling and production system intensification on soil physical–hydric properties and soybean performance. The experiment was conducted in São José do Ouro, Rio Grande do Sul, Brazil, from September 2023 to April 2025. The experimental design consisted of three factors: soil management (spring 2023 chiseling, autumn 2024 chiseling, and a no-till control), post-maize cover (millet and fallow conditions), and winter cover crops (black oat, white oat, vetch, and radish) grown either as monocultures or in mixtures. A randomized block design with split plots and three replicates was used. The evaluated variables included dry biomass of winter cover crops, soil bulk density, total porosity, microporosity, macroporosity, soil water content at field capacity, soil penetration resistance, plant gas exchange, leaf area index, thousand-grain weight, and soybean grain yield. The results indicated that soil chiseling altered soil physical properties by reducing soil bulk density, penetration resistance, microporosity, and field capacity, while increasing total porosity and macroporosity. Soil chiseling promoted short-term increases in thousand-grain weight and soybean grain yield, with no persistent effects after 20 months. Production system intensification, through the use of cover crops and millet, did not affect grain yield but increased stomatal conductance and soybean leaf area index. Therefore, occasional tillage in high-clay subtropical Oxisols should be strategically applied and associated with long-term conservation agriculture practices to sustain improvements in soil physical quality. Full article

This study investigates agar–starch composite bioplastic films formulated with five agar-to-starch ratios (1:1, 2:1, 3:1, 4:1, and 5:1) to evaluate how composition influences material performance. Films were produced by solution casting with glycerol as a plasticizer and characterized through tensile testing (ASTM D882-18), DSC, TGA, FTIR, water absorption measurements, physical property assessment, and biodegradability tests including water, UV, and soil degradation. Mechanical results showed that the 3:1 formulation (A3S1) exhibited the highest tensile strength (2.78 MPa) with moderate elongation (57.25%), while the 1:1 formulation (A1S1) showed the greatest flexibility (76.38% elongation) but lower strength (2.07 MPa). Thermal analysis indicated improved thermal stability with increasing agar content, with onset degradation temperatures ranging from 42.89 °C to 51.84 °C and melting points from 99 °C to 108 °C. FTIR spectra showed no new major absorption bands, with only minor shifts in selected bands, indicating component interactions without evidence of new chemical bond formation. Films with higher starch content displayed increased thickness, weight per area, and water absorption. Overall, adjusting agar–starch ratios produced distinct combinations of mechanical, thermal, and physical properties, with the 3:1 ratio offering the best balance of strength and water resistance. All formulations showed measurable biodegradation under water, UV, and soil conditions, indicating environmental degradability. Full article

The suction caisson foundation has been extensively adopted for offshore wind turbine infrastructure owing to its adaptability to deep-water environments, cost-effectiveness, and convenient construction. However, such foundations suffer from relatively low horizontal and vertical bearing capacities when embedded in soft clay deposits. To address this limitation, this study proposes a novel mobile jet-reinforcement technique and the corresponding composite suction caisson configuration. Physical model tests are conducted to investigate the soil fracturing-erosion mechanism induced by jet injection and the bearing performance of the reinforced composite foundations. Test results reveal that the soil breaking depth increases with injection pressure and injector diameter, whereas the soil breaking width increases with jet angle. Larger breaking depth and width contribute to an expanded horizontal–vertical bearing capacity failure envelope. The ultimate bearing capacity of the composite caisson increases with greater soil breaking depth, and a larger number of circumferentially arranged jet pipes enables more uniform cement–soil cladding around the caisson body. Overall, the reinforced foundations achieve a bearing capacity 3.0–5.0 times that of conventional unreinforced suction caissons. Furthermore, a time-dependent hyperbolic model for soil breaking depth prediction and a bearing capacity failure envelope method are established for the reinforced composite suction caissons. The outcomes of this study can provide a reference for the engineering design of jet-reinforced suction caisson foundations in offshore areas with soft clay. Full article

Efficient nutrient management through fertigation is essential for sustaining table grape production under water-limited Mediterranean environments. This study evaluated the effects of graded potassium (K) fertigation rates on yield and berry quality of grapevines under semi-arid conditions in northern Jordan. Field experiments were conducted over three consecutive seasons at three locations using four potassium application rates (0, 100, 200, and 300 kg K₂O ha⁻¹) applied through drip fertigation and synchronized with key vine phenological stages. Yield and fruit-quality parameters were analyzed using linear mixed-effects models accounting for treatment, year, location, and their interactions. Potassium fertigation significantly increased total yield, cluster weight, and berry physical attributes, including firmness, volume, weight, and diameter, whereas total soluble solids (TSS) and juice pH were largely unaffected. Relative to the control, potassium fertigation progressively increased total yield per vine by approximately 21%, 47%, and 72% under the 100, 200, and 300 kg K₂O ha⁻¹ treatments, respectively, although the magnitude of response differed among locations and growing seasons. Significant treatment × location interactions indicated that site-specific soil conditions influenced potassium response. These results demonstrate that synchronizing potassium supply with vine phenological demand through fertigation enhances productivity and berry physical quality without compromising fruit chemical composition. The observed improvements are consistent with the established physiological roles of potassium in osmotic regulation, assimilate transport, and berry development, supporting optimized potassium fertigation as a key component of precision nutrient management for sustainable viticulture in semi-arid Mediterranean regions. Full article

Expansive soil slopes are highly susceptible to rainfall-induced shallow failures due to cyclic swelling–shrinkage behavior governed by matric suction variation. This study proposes a composite frame–geosynthetic system (CFGS), comprising a rigid frame integrated with high-performance turf reinforcement mats (HPTRMs), for expansive soil slope protection. The performance of the CFGS was evaluated through geometrically scaled, materially representative physical model tests under repeated wetting–drying cycles and further examined using coupled hydro-mechanical numerical simulations in COMSOL Multiphysics. A bare slope and an HPTRM-protected slope were used for comparison. Under identical laboratory conditions, CFGS reduced cumulative erosion to approximately 13% of that of the bare slope. It also moderated the internal hydraulic response, reducing pore-water pressure fluctuation by approximately 26%, and restrained swelling–shrinkage deformation, with an average deformation attenuation of up to 61%. The numerical simulations showed consistent response trends with the physical model tests, supporting the proposed mechanism of hydraulic regulation, deformation restraint, and stress redistribution. Overall, the results demonstrate the comparative effectiveness of CFGS in mitigating wetting–drying-induced deterioration of expansive soil slopes. Full article