Geotechnical behaviour and seawater durability of marine soft soil stabilized using nano-clay modified geopolymer with flax fiber reinforcement

From waste to restoration: Straw-derived artificial humic acid activated magnesium-modified biochar for efficient adsorption of Zn²⁺/Cd²⁺ and soil stabilization

Thermal impact of elevated crude oil temperature on long-term stability of buried pipeline foundation soils in Northeast China

Stabilization of weak subgrade soil using lime and fly ash: A case study from Afghanistan

To investigate the vibration isolation performance of concrete-filled trench in pile–net composite foundations under high-speed train loading, a validated three-dimensional finite-element model integrating track, embankment, pile, soil, and concrete-filled trench was established. The results indicate that in pileless foundations, stress waves concentrate in surface soils, whereas in pile–net foundations, they localize at interfaces between the concrete-filled trench and layered soils, distributing throughout the foundation depth and enabling full-depth isolation. Before the concrete-filled trench, pile–net composite foundations exhibit lower dominant frequencies but higher vibration amplitudes than pileless foundations. After the concrete-filled trench, the overall vibration isolation effect is improved, with a higher dominant frequency but a smaller vibration amplitude at the dominant frequency. Moreover, the trench effectively filters medium-to-high-frequency vibrations (above 20 Hz) behind the barrier, with residual energy concentrating below 20 Hz. Parametric analyses demonstrate that reducing the pile spacing can enhance both the vibration isolation effect and its stability. Increasing the pile length and pile diameter can improve the vibration isolation effect in the post-trench area, although the benefit of length diminishes beyond the combined thickness of the top two soil layers. Trench depth is the most influential geometric parameter. Although flexible barriers achieve superior isolation, rigid barriers such as concrete can provide more stable attenuation behind it and ensure structural stability in soft soils, making them a more practical choice in many applications. This study reveals the synergistic mechanism of pile–net foundations and concrete-filled trenches in redistributing stress waves and optimizing isolation, providing critical design insights for combined vibration mitigation in high-speed railway projects.

Sustainable construction from industrial waste: synergistic stabilization of granite residual soil using red mud byproduct and nano-silica

Unveiling the regulation of biochar and ferrihydrite on organic carbon stabilization, CH4 emission and microbial community in paddy soil.

Soil organic carbon in Ultisol landscapes: Influence of erosion rates, soil development, depth, and hillslope properties

Expansive soils exhibit pronounced swelling-shrinkage behavior, low shear strength, and high moisture sensitivity, posing significant challenges to the stability of geotechnical structures such as embankments and tailings dam slopes. In this study, a sustainable stabilization strategy integrating enzyme-induced carbonate precipitation (EICP) with iron ore tailings is investigated to improve the hydro-mechanical performance of expansive soils. A comprehensive experimental program was conducted to evaluate changes in unconfined compressive strength (UCS), swelling pressure (Ps), hydraulic conductivity (Ks), cohesion (c), and internal friction angle (φ). Microstructural characterization using scanning electron microscopy and X-ray diffraction was performed to examine calcium carbonate precipitation and its cementation effects within the soil matrix. The results demonstrate that the combined EICP-iron ore tailings treatment significantly enhances soil performance, with UCS, c, and φ increasing by approximately 113%, 48%, and 98%, respectively, while Ps and Ks decrease by approximately 98% and 69%. Furthermore, seepage and slope stability analysis using GeoStudio (SEEP/W and SLOPE/W) indicate that the stabilized soil achieves a markedly higher factor of safety (FoS = 1.896) compared to untreated soils. The findings confirm that the synergistic integration of EICP and iron ore tailings provides an effective, environmentally sustainable, and engineering-feasible solution for stabilizing expansive soils and improving slope performance in tailings dam applications.

A comprehensive review on all-solid-waste cementitious materials: activation, preparation, sustainable performance and applications.

ABSTRACT Cadmium (Cd) and arsenic (As) accumulate in soils due to their persistence, posing a global remediation challenge. This study investigated the effectiveness of ferromanganese-modified biochar (Fe–Mn–BC) for stabilizing Cd and As and explored the underlying mechanisms. Soil incubation experiments were conducted using TCLP, CaCl₂-extractable Cd, NaH₂PO₄-extractable As, and BCR sequential extraction. After 60 days of Fe–Mn–BC application, extractable Cd and As decreased from 0.65 to 0.29 mg kg−1 and from 11.42 to 6.99 mg kg−1, respectively, indicating enhanced stabilization. The amendment promoted transformation of mobile fractions (weak-acid Cd and reducible As) into more stable residual forms, thereby limiting metal mobility. Soil pH remained stable (7.67–7.96), supporting the stabilization process. Overall, Fe–Mn–BC reduced the bioavailability and ecotoxicity of Cd and As. Among treatments, Fe₀.₁–Mn₀.₁ BC showed the highest effectiveness, followed by Fe₀.₁–Mn₀.₀₅ BC, Fe₀.₀₅–Mn₀.₁ BC, and BC.

Biopolymer-based soil stabilization has attracted increasing attention as a sustainable approach in geotechnical engineering. However, accurate prediction of the compressive strength of biopolymer-stabilized soils remains challenging due to the complex interaction among soil properties, additive characteristics, and curing conditions. In this study, a comprehensive database comprising 248 unconfined compressive strength (UCS) tests on soils stabilized with xanthan gum was compiled and analyzed, and a unified and interpretable predictive framework applicable to a wide range of soil types and curing conditions was developed. To derive an explicit numerical relationship, a white-box machine learning algorithm based on the Group Method of Data Handling (GMDH) was employed to predict UCS. The input parameters included plasticity index (PI), xanthan gum content (XGC), curing time (CTi), curing temperature (CTe), initial moisture content (WMC), and the unconfined compressive strength of untreated soil (q0). The developed model demonstrated strong predictive capability for the compiled dataset, achieving an overall coefficient of determination of R2 = 0.883. When evaluated on an independent testing subset, the model yielded an R2 value of approximately 0.75 with an RMSE of 0.62MPa, indicating satisfactory generalization performance. Sensitivity analysis using both SHAP-based global interpretation and classical approaches indicated that intrinsic soil properties and curing-related variables govern UCS, with the unconfined compressive strength of untreated soil and plasticity index identified as the most influential parameters. These findings provide a quantitative prediction tool and physically consistent insight into the behavior of xanthan gum-stabilized soils, offering practical guidance for engineering applications.

Wind erosion in arid and semi-arid regions poses a significant global environmental challenge, threatening infrastructure and human health. Conventional enzymatic-induced carbonate precipitation (EICP) for soil stabilization, while effective, relies on the natural urease enzyme extracted from plants or microorganisms, thereby being limited by extraction methods, purification levels, and the availability of biological sources, as well as the natural enzyme's environmental sensitivity. This study introduces a novel approach utilizing synthetic urease-mimetic catalysts to induce calcite precipitation for dust suppression. Two Schiff base complexes, derived from glycine and salicylaldehyde with central metal ions of copper(II) and zinc(II), were synthesized and evaluated as catalysts for urea hydrolysis. The zinc-based complex was selected as the superior catalyst based on higher calcite precipitation yield and lower cost. Through response surface methodology (RSM) and wind tunnel testing on erodible siliceous sand, the optimal application parameters were determined to be a solution containing 8g/L urea, 13g/L CaCl₂, and 1g/L Zn-complex applied at a rate of 1.65L/m². This treatment effectively reduced wind erosion to negligible levels (mass loss per original mass of the sample ~ 1%). Supplementary tests, including successive wet-dry cycles, surface strength measurement, and SEM analysis, confirmed the formation of a durable calcite crust that bonds soil particles, increasing surface strength to over 150kPa. The stabilized soil exhibited excellent resistance to simulated environmental stressors, including heat (50°C) and long-term aging (one year), with only a minimal increase in erosion (mass loss percent of 1.5%). This research demonstrates that Schiff base complexes, particularly the zinc variant, are highly effective and durable catalysts for soil stabilization via chemical carbonate precipitation, offering a promising alternative to biological enzyme-based methods.

Lignin from mustard stalks as a reinforcing scaffold for multifunctional bio-hydrogels with enhanced water retention and controlled nutrient release.

Impact of soil legacy on soil organic carbon partitioning in mangrove wetlands: a density-based fractionation and X-ray photoelectron spectroscopy study.

ABSTRACT Desiccation cracks in expansive clayey soils reduce shear strength and increase permeability, posing significant challenges in geotechnical and geoenvironmental engineering. Accurate crack segmentation is essential for evaluating soil stability and mitigating infrastructure risks. This study proposes a deep learning-based semantic segmentation approach using DeepLabv3+, for automated detection of soil desiccation cracks. A dataset of 820 manually annotated, laboratory-acquired images of Kaolinite clay was used for training, validation, and testing with four backbone architectures i.e. MobileNetV2, ResNet-18, ResNet-50, and Xception. Model performance was assessed using precision, recall, F1 score, and Intersection over Union (IoU). Results show that DeepLabv3+ effectively segments cracks across all backbones. Xception achieved the highest accuracy, with precision of 89.39%, recall of 91.64%, F1 score of 90.50%, and IoU of 82.65%, while ResNet-18 demonstrated superior computational efficiency for real-time applications. These findings support accurate and efficient soil crack detection, advancing automated geotechnical analysis and monitoring.

To assess the effectiveness of Smash-Ridging Tillage in improving soil structure and fertility, this study compared the impacts of traditional rotary tillage at 20cm depth and Smash-Ridging Tillage at depths of 20cm and 40cm (F40) on soil aggregate distribution and stability meanwhile with its soil organic carbon characteristics in sugarcane fields of Guangxi, China. The results demonstrated that Smash-Ridging Tillage significantly reduced soil bulk density and enhanced soil total nitrogen content. Notably, it markedly increased the proportion of water-stable macroaggregates (> 0.25mm) (p < 0.05), with the F40 achieving the highest macroaggregate content (51.17-60.72%). Aggregate stability, as indicated by mean weight diameter (MWD) and geometric mean diameter (GMD), was also significantly improved under Smash-Ridging Tillage. Pearson correlation and redundancy analyses revealed that macroaggregate content and the contribution rate of organic carbon associated with macroaggregates were positively correlated with MWD and GMD, but negatively correlated with fractal dimension and soil erodibility factor. The F40 showed the highest contribution rate of macroaggregate organic carbon, which was approximately 20.58-32.57% higher than that under traditional rotary tillage. Overall, deep smash-ridging tillage at 40cm significantly improved soil structural stability, which enhanced organic carbon stabilization within macroaggregates, providing a scientific reference for optimizing tillage practices to improve soil structure and organic carbon sequestration in subtropical sugarcane fields.

Microbially induced carbonate precipitation (MICP) is promising for soil stabilization. However, its large-scale application is hindered by the cost of laboratory-grade yeast extract (YE), which often accounts for more than 70% of cultivation medium expenses. Here, we evaluate two standardized industrial nitrogen sources-industrial yeast extract (IYE) and soy peptone (SP)-as complete or partial replacements for YE in Sporosarcina pasteurii cultivation. Urease activity and the performance of bio-cemented sand columns were assessed via unconfined compressive strength (UCS), CaCO3 content, and mineralogical/microstructural analyses. Results indicated that the partial substitution scheme of 5 g/L pure YE + 10 g/L IYE yielded the best overall outcomes: bacterial urease activity reached ~80% of the control, UCS reached 4.27 MPa (9% higher than the control), and the nitrogen-source cost was reduced by 65.53%. The enhanced strength correlates with a favorable precipitation pathway that produced predominant calcite (~95.57% of the CaCO3 precipitate), together with a dense, interlocking microstructure. In contrast, SP-substituted media produced lower UCS despite a high CaCO3 content (up to 15.31%), indicating that mechanical performance depends not simply on the total amount or final polymorph of CaCO3, but on the combined effects of polymorph composition, precipitation pathway, and the resulting microstructural organization. Overall, the proposed YE-IYE blending strategy offers a practical route to lower-cost, higher-performance MICP sand stabilization.

Abstract— This review paper analyzes different laboratory tests conducted on soil stabilized with lime and fly ash, including sieve analysis, Atterberg limits test, standard proctor compaction test, California Bearing Ratio (CBR) test, and unconfined compressive strength (UCS) test. The results show that stabilization significantly improves soil strength, increases bearing capacity, and reduces swelling potential. The combination of lime and fly ash provides an economical and environmentally sustainable solution for improving expansive soils. Keywords— Soil Stabilization, Lime, Fly Ash, Black Cotton Soil, CBR Test, Compaction Test, UCS Test

Abstract. Although soil C is a critical component of soil health, studies robustly exploring the agronomic and pedoclimatic effects on soil C are limited, especially at the landscape scale. Therefore, a dataset of 1490 topsoil samples from agricultural fields across Ontario was used to evaluate the impacts of agronomic and pedoclimatic factors on eight soil C indicators including chemistry and thermal stability of soil C using the programmed pyrolysis approach. Soil C quality and stability were largely controlled by the inherent soil characteristics such as soil texture. Significant interactive effects of cropping system and tillage intensity on soil C indicators were observed; however, the number of significant effects varied among the three soil textural classes. All soil C indicators were significantly different among the cropping systems for the coarse textured soils, but the cropping system differences decreased under medium and fine textured soils. From the pyrolysis analysis, the hydrogen index (HI) and oxygen index (OI) also confirmed that the soil C chemistry was influenced by the cropping system. For instance, orchard systems had stable pools of soil C whereas vegetable systems were associated with less advanced degree of soil C decomposition. Remaining soil management variables (cover crop use, tillage intensity, and organic amendments) had a weaker influence than cropping systems and soil textural classes on soil C indicators. Principal component analysis revealed a close association of soil C indicators with the mean annual precipitation (MAP) and cropping system; suggesting that the quantity and quality of soil C inputs associated with different cropping systems and increase in precipitation had a large influence on soil C. Our results confirm the significant effects of agronomic and pedoclimatic variables on chemistry, thermal stability, and composition of soil C pools, which have long-term implications on soil C storage, mitigating global climate change, and improving soil health.