Abstract In semi-arid regions like Wadi El-Madamud, Egypt, sustainable groundwater management is hindered by the intricate interplay of structural, lithological, and climatic controls on aquifer recharge and storage. Despite the hydrogeological importance of the Plio-Pleistocene aquifer, integrated assessments for delineating groundwater potential zones (GWPZs) remain limited. This study bridges this gap through a multi-source, GIS-based approach combining conventional (geology, soil, rainfall), remote sensing (Sentinel-2 for LULC, Landsat 8–9 for NDVI, ASTER-GDEM for topography), and geophysical data (aeromagnetic and DC resistivity) within an analytic hierarchy process (AHP) framework. Ten thematic layers—geology, soil, slope, elevation, drainage density, lineament density, rainfall, topographic wetness index (TWI), LULC, and NDVI—were integrated using AHP-weighted overlay (consistency ratio = 0.05). The region’s stratigraphy spans Cretaceous to Holocene, with soils (Lithosols, Calcaric Fluvisols, Eutric Regosols, Calcic Yermosols) exhibiting differential infiltration and retention. GWPZ mapping classified the area into five categories: excellent (0.16%), good (25.54%), moderate (21.01%), fair (52.17%), and poor (1.12%), with high-potential zones localized along the Nile Valley fringe due to permeable Quaternary–Holocene sediments, Calcaric Fluvisols, and favorable topography. Model accuracy was validated using hydrochemical data from 15 wells, revealing a fresh to slightly saline gradient (TDS: 366–1541 mg/L), and ROC-AUC of 0.72. Aeromagnetic analysis identified dominant structural trends (N–S, E–W, NE–SW, NW–SE) and basement depths (100–1250 m), while DC resistivity (31 VES points, Schlumberger array, AB ≤ 1000 m) revealed a four-layer subsurface: consolidated wadi deposits (> 1000 Ω·m), saturated sand aquifer (≤ 100 Ω m, 25–85 m thick, 15–40 m depth), dry compacted sand (10 3 –10 4 Ω m), and Thebes Formation limestone (10 4 –10 5 Ω m). The study recommends cross-validation with MIF and Fuzzy AHP and prioritizes drilling in north-central, southwestern, and northeastern zones. By integrating surface and subsurface datasets, this work advances hydrogeological modeling in structurally complex terrains and provides a replicable framework for groundwater exploration in arid and semi-arid regions.

Finite-element (FE) studies of tapered steel jacking piles with different diameters, installed in saturated and dry sands with various relative densities, were carried out and subsequently validated against full-scale experimental results. The purpose of this paper is to find an optimal way of numerically modelling tapered displacement piles installed in dry and saturated soil conditions and adopt the empirical relationships for predicting the bearing capacity components of this type of displacement pile incorporating the installation effects, whereby the bearing capacity factor, Nq, and coefficient of lateral earth pressure, K, were back-calculated. In numerical simulations, three-stage models are developed using two constitutive soil models: the HS-small model (hardening soil model with small-strain stiffness) and the UBC3D-PLM model. In addition, to improve the accuracy of the FE results, soil–soil interface elements are introduced based on the previously identified failure mechanisms from wished-in-place FE analysis.

Dynamic p-y curves for flexible retaining walls in dry sand

Abstract Exposed soil, due to low vegetation cover or in open canopy crops, influences scene reflectance derived from remotely sensed data. An experiment was conducted in College Station, TX, to investigate the potential of six unmanned aerial systems (UASs)‐derived and proximally sensed vegetation indices (VIs) in suppressing soil background brightness of four treatments in 2020 and 2021. The treatments were dry soil, dry soil with winter wheat ( Triticum aestivum L.) crop residue, wet soil (WS), and wet soil with winter wheat crop residue (CRWS) in 2020. In 2021, WS and CRWS were replaced with dry sand and dry compost (DC). The VIs were calculated from remotely sensed data of treatment plots. Cotton ( Gossypium hirsutum L.) canopy cover (%) on different dates of UAS flight was extracted using unsupervised classification. Factors such as shadows, crop residue, soil moisture, and uneven canopy growth influenced the scene reflectance. The shadow on the soil decreased the soil background reflectance to <10%. Soil background variations minimally impacted the UAS‐derived VIs. Soil wetness resulted in higher normalized difference vegetation index (NDVI) than dry treatment plots at an estimated mean canopy cover > 30% in 2020. Similarly, higher NDVI was observed for DC treatment plots at an estimated mean canopy cover of <35% in 2021. The perpendicular vegetation index was least influenced by canopy cover or soil background variations. The study suggests that UAS can be used for large‐scale research without being affected by soil variability when vegetation cover is above 30%.

Evaluation and characterization of microplastics in beach sand from three different Syrian coastal locations.

Rainfall-driven hazards such as landslides, debris flows, and earthen dam failures often arise when water changes the internal strain within sand. This study evaluates the ability of distributed acoustic sensing to monitor these strain changes in real time. We embed a fiber-optic cable in a sand-filled glass cylinder and run controlled dry- and wet-sand experiments to measure how strain develops as water infiltrates, saturates, and drains from the sand. The sensing system detects uneven water movement in dry sand and enables millimeter-scale estimates of infiltration rates, and in wet sand it tracks rising water levels, delayed strain peaks after saturation, and abrupt strain shifts during drainage. These results show that fiber-optic sensing captures subtle strain evolution throughout the full water-sand interaction cycle. The study demonstrates that fiber-optic sensing offers promising potential for real-time and cost-effective monitoring and early warning of rainfall-induced geohazards.

This study examines the dynamic behavior of soil-pile-superstructure systems (SPSs) with different pile head connections (fixed versus hinge) using 1g shaking table tests supported by analytical evaluations. Two loading protocols—frequency sweep and steady sinusoidal excitation—were applied to assess resonant frequency, acceleration, displacement, and bending moments under dry and liquefiable sand conditions. Results show that resonant frequency varies systematically with soil state and pile head restraint, with greater sensitivity in liquefiable soils. Under saturation, hinge-head systems exhibited higher superstructure accelerations and larger displacements. This amplification resulted from reduced shaft confinement during liquefaction, which concentrated pile bending demand at the pile tip. The reduced lateral support from liquefied soil allowed unrestricted pile-head rotation, directly transmitting inertial loads to the pile-tip region. Although global displacements grew, inter-story drifts did not increase proportionally, indicating redistribution of deformation through foundation rocking. Overall, uncertainties in pile head fixity can amplify structural demands relative to fixed-head connections. These findings provide practical insight for performance-based dynamic design of pile-supported buildings, highlighting the importance of reliable head restraint for system safety, resilience, and sustainable construction.

Diamond reinforced Al0.5CoCrFeNiTi0.5 high-entropy alloy (HEA) coatings were prepared on 30CrMnSi substrate by laser cladding in this work. The abrasive wear behavior and mechanism of the prepared coatings were evaluated by a dry sand rubber wheel test. The results show that the hardness of the HEA coatings can be greatly improved by adding diamond particles. The hardness of the HEA coating with 15 vol.% diamond reaches 706 HV1.0, which is 3 times that of the substrate and 35% higher than the coating without diamond addition. The abrasive wear resistance of the diamond reinforced HEA coatings is much higher than that of the substrate and the HEA coatings without diamond addition. The wear rate of the HEA coating with 15 vol.% diamond addition is only about 1/14 of that of the 30CrMnSi substrate and 1/13 of that of the HEA coatings without diamond addition. The main abrasive wear mechanisms of the samples are micro-cutting and surface plastic deformation. For the substrate and HEA coatings without diamond, micro-cutting dominates due to the low hardness, forming narrow and deep grooves on the samples surface. While for the diamond reinforced HEA coatings, surface plastic deformation dominates. At the same time, the diamond particles in the coatings hinder the plastic deformation and micro-cutting during the abrasive wear process, resulting in the further increase of the wear resistance of the diamond reinforced HEA coatings.

Understanding the particle crushing behavior of sand under high compressive stress is critical for accurate prediction of soil compressibility and strength characteristics. This study examines the particle breakage characteristics of Melamchi river sand under extreme vertical loads using a Compression Testing Machine (CTM). Dry sand specimens were placed in a CTM machine and loaded step-by-step upto 1000 kN (about 53 MPa). Particle size distribution analysis was done before and after each test to find D10, D20, D50, D60 and coefficient of uniformity (Cu) . Breakage indices were calculated to quantify the degree of particle breakage. Results show upto 59% reduction in mean particle size with increasing stress levels at 1000 kN. The findings confirm that grain crushing must be considered in geotechnical infrastructure works like deep pile foundations, rockfill dams, embankments and hydropower tunnels, where high stresses occur. The findings are useful for the design of gravel drains and soil filters, where stress-induced particle crushing can change gradation and influence filtration performance.

The angle of repose is a fundamental parameter for assessing the stability of coral reefs. However, predictive models for this angle are currently lacking. In this study, a series of laboratory experiments were undertaken to investigate the angle of repose by varying moisture content, particle shape, and particle size. Based on our experimental data, variation in the angle of repose with moisture content is classified into five distinct zones. It is demonstrated that the range of moisture content for each zone varies with particle size. Coral sands of dendrite, flake, rod, and block particles have a descending order of angle of repose, as demonstrated for a sieve size of 4.5 mm. The angle of repose for dry, submerged, and steady coral sands exhibits a correlation with the nominal diameter of particle size. Finally, extended models are proposed for predicting the angle of repose of coral sands (R2 = 0.8, Dn50 = 0.317−5.470). To facilitate use of these models, a linear relationship between sieve particle size diameter, nominal particle size diameter, and Corey shape factor, allowing for conversion among these parameters, is established. This study thereby helps to enhance our understanding of how moisture content affects angle of repose and improve our ability to predict the angle for coral grains with intricate geometries.

The shallow foundations constructed near slopes alter the bearing capacity, creating challenges that are different from those on level ground. In addition, distinct deformations occur within the soil beneath the footing, associated with the resulting slope failure mechanism. This paper examines a series of small-scale physical modeling tests designed to investigate the bearing capacity behavior and failure mechanisms of strip footings placed on dry sand slopes. The model tests were conducted with varying setback distance ratios (D/B) and relative density conditions. The Particle Image Velocimetry (PIV) technique was utilized to monitor the soil distortion patterns and the progress of the failure surfaces during loading. According to the PIV analysis results, the failure mechanism of shallow footing near slopes is significantly influenced by the footing’s position relative to the slope face. The results indicated that increasing the setback distance leads to a related linear rise in the ultimate bearing capacity (qu), with a critical setback distance ratio of D/B = 2, beyond which the influence of the slope becomes negligible at D/B ≥ 5. The failure surface geometry and displacement fields obtained from the PIV analysis closely reflect the transition from the bearing capacity failure to the slope stability failure. These findings highlight the role of setback distance and relative density on the footing performance near slopes. Furthermore, the application of PIV techniques proves to be a reliable and effective approach for observing the complex failure mechanisms, offering advantages over conventional theoretical methods.

Near-fault velocity pulse effects on earthquake response of a dry sand site: Centrifuge modeling

In this work, hemp/bamboo hybrid fabric-epoxy composites reinforced with 0-9 wt% microcrystalline cellulose (µCC) is examined for their abrasive wear behavior. Compression molding was used to create composites with 0, 3, 6, and 9 wt% µCC. In accordance with ASTM G65 guidelines, wear tests were conducted under controlled dry sand abrasion. Using a Taguchi L16 design, the effects of applied load (5-20N), abrading distance (250-1000m), and µCC content on wear loss were assessed. To predict abrasive wear and examine the role of µCC filler, several machine learning models were used, including Linear Regression, K-Nearest Neighbors, Artificial Neural Networks, Random Forest, Gradient Boosting, and eXtreme Gradient Boosting. By increasing the hardness and load-bearing capacity of the composite, µCC mechanistically increases wear resistance and lessens material removal during abrasion. According to ANOVA results, wear loss was most affected by abrading distance (44.08%), load (34.21%), and µCC content (18.01%). The Random Forest model had the lowest error (RMSE = 0.045) and the highest predictive accuracy (R2 = 0.942). Abrading distance is the main factor influencing wear resistance, followed by load and µCC content, according to feature importance analysis. Accurately forecasting abrasive wear and creating high-performance, sustainable hybrid composites can be accomplished by combining machine learning and experimental data.

In sandy soils, skin resistance efficiency is critical, as it governs load capacity, settlement, and foundation cost. This study investigates pile foundations with directional surface asperities embedded in uniform sand to clarify the limited knowledge of how asperity orientation (cranial vs. caudal), geometric ratio (L / H), and pile diameter affect axial load transfer. Experimental tests were conducted on steel piles with diameters of 10, 12, and 15.85 mm under smooth, cranial, and caudal conditions with L / H ratios of 20, 26.67, and 33.33. Axial compression tests following ASTM D1143-20 in controlled dry sand provided ultimate load and shaft resistance data, validated by one-way ANOVA. The results show that cranial asperities consistently outperformed other surfaces, with the Cr L / H 20 configuration on the 15.85 mm pile reaching 0.368 kN, a 392.51% increase over smooth piles, while caudal asperities achieved only 134.30%. Cranial asperities also mobilized shaft resistance more uniformly along the pile, reducing end-bearing reliance. This performance is explained by stronger passive interaction at the pile-soil interface, which raises normal stress and friction mobilization. The distinctive feature of this research is the identification of the L / H ratio as a measurable design parameter, with L / H = 20 found to be optimal, in contrast to previous studies that described roughness only qualitatively. The findings demonstrate practical potential for applying cranial asperity designs in pile foundations for light- to medium-scale infrastructure on sandy soils, such as bridges, wharves, and transmission towers, enabling shorter or fewer piles without compromising safety while improving cost efficiency and geotechnical performance

In sandy soils, skin resistance efficiency is critical, as it governs load capacity, settlement, and foundation cost. This study investigates pile foundations with directional surface asperities embedded in uniform sand to clarify the limited knowledge of how asperity orientation (cranial vs. caudal), geometric ratio (L / H), and pile diameter affect axial load transfer. Experimental tests were conducted on steel piles with diameters of 10, 12, and 15.85 mm under smooth, cranial, and caudal conditions with L / H ratios of 20, 26.67, and 33.33. Axial compression tests following ASTM D1143-20 in controlled dry sand provided ultimate load and shaft resistance data, validated by one-way ANOVA. The results show that cranial asperities consistently outperformed other surfaces, with the Cr L / H 20 configuration on the 15.85 mm pile reaching 0.368 kN, a 392.51% increase over smooth piles, while caudal asperities achieved only 134.30%. Cranial asperities also mobilized shaft resistance more uniformly along the pile, reducing end-bearing reliance. This performance is explained by stronger passive interaction at the pile-soil interface, which raises normal stress and friction mobilization. The distinctive feature of this research is the identification of the L / H ratio as a measurable design parameter, with L / H = 20 found to be optimal, in contrast to previous studies that described roughness only qualitatively. The findings demonstrate practical potential for applying cranial asperity designs in pile foundations for light- to medium-scale infrastructure on sandy soils, such as bridges, wharves, and transmission towers, enabling shorter or fewer piles without compromising safety while improving cost efficiency and geotechnical performance

Abstract. The presence of illegal waste materials is one of the most significant challenges for environmental management and human health. Therefore, their identification reduces environmental hazards significantly. Recently, Unmanned Aerial Vehicles (UAVs) equipped with advanced sensors and specialized machine learning algorithms allow for early identification of illegal waste dumping sites. In this scenario, is pivotal to fine-tuning image-based automatic detection and classification procedures with geo-intelligence data obtained in field acquisition campaign conducted in semi-controlled environment. This study aims to identify illegal waste dumping sites by considering the characteristics of waste materials. The testing activities aimed to evaluate a selected list of UAV payload sensors, and the data derived from them, including thermal and multispectral images, to assess their ability to be utilised for automatic waste detection. For this study, the design and testing of a trial site and relative UAV surveying campaign were conducted to mimic the potential presence of waste materials. Regarding the passive thermal response of the surveyed site, a convergence procedure was implemented through R script to calibrate the raw images. Through photogrammetric reconstruction and GNSS-RTK (Global Navigation Satellite System - Network Real Time Kinematic) control point surveying, multiband georeferenced orthomosaic products have been obtained. The calibrated thermal orthophoto was used for the preliminary identification of the waste materials, in particular distinguishing wet sand from dry sand. While the Semi-Automatic Classification Plugin in QGIS was applied to the multispectral orthophoto by utilising materials' spectral signatures to classify the different types of waste materials.

Abstract The primary goal of this paper was to determine if there is a difference in the intensity of abrasive wear on the radial and tangential sections of sessile oak ( Quercus petraea ) in the direction that matches or opposes the primary growth direction of the tree. The resistance to abrasion was tested on the samples using the standard 'dry sand–rubber wheel' method in both directions and on both sections. Owing to the heterogeneity of the wood structure, the abraded mass was recalculated to the abraded volume. It was found that changing the direction of abrasion relative to the primary growth direction significantly affects the abraded volume on both sections, particularly on the radial section. Abrasion was more intense when the direction of wear opposed the primary growth direction in both sections. The smallest abraded volume was measured on the radial section in the primary growth direction, and the largest was measured on the same section in the opposite direction. The distribution of results was analyzed using the Weibull distribution, with less dispersion observed in the radial section compared to the tangential section in both wear directions. The total volume loss from abrasive wear in both directions was only 3.7% greater in the tangential section compared to the radial section. These results are attributed to the complex and highly oriented microstructure of oak wood, but still not fully understood.

Sea turtle hatchlings display maneuvering capabilities across diverse aquatic and coastal terrains. While turning behavior is crucial in aquatic environments, it is equally vital for terrestrial locomotion by hatchlings that must quickly navigate obstacle-rich terrain on their way to the sea. This study introduces a robotic prototype that emulates the turning strategies of juvenile sea turtles to optimize turning rate and energy consumption across diverse terrestrial surfaces. The research investigates the rotational displacement capabilities of a bioinspired robot across five distinct gait configurations: one involving all flippers in a unique pattern, and four employing reduced flipper combinations, including front, diagonal, back, and single flippers. We investigated the robot's turning capabilities on diverse granular and compliant media, including four specified rock sizes, a consistent foam platform, and dry sand. Comparative analyses were conducted using rigid and soft flipper designs. Key locomotion features, including roll, pitch, yaw, and lift height, were quantified for each configuration. The results reveal significant differences in rotational behavior across terrains and gait styles, highlighting the interplay between flipper design, gait strategy, and environmental adaptability. This research advances the understanding of bioinspired robotics for applications in complex and variable environments.

Pile-anchor foundations, serving as one of the anchoring solutions to ensure the safety and stability of floating offshore wind turbines, are primarily subjected to inclined loading induced by anchor chain forces, resulting in significantly different bearing behavior compared to conventional vertically loaded pile foundations. However, experimental research on the inclined pullout performance of anchor piles remains insufficient. To address this gap, this study employs a self-developed servo-controlled loading system to investigate the pullout bearing characteristics of anchor piles in dry and saturated sand, considering factors such as pullout angle and loading point depth. The research results show that from the load–displacement curve of the model pile, it can be found that with the increase in displacement, the load it bears first gradually increases to the peak, then decreases, and then gradually stabilizes. The loading angle has a significant impact on the bearing performance of pile-anchor foundations. As the loading angle increases, the failure mode shows pullout failure. When the loading angle increases from 30° to 60°, the bearing performance of the pile foundation decreases by approximately 63%. When the depth of the loading point increases from 0.22 times the pile length to 0.78 times the pile length, the diagonal anchor tensile bearing capacity of the model pile increases by approximately 45%. When the depth of the loading point is the same, the distribution patterns of bending moment and shear force are basically similar. However, the smaller the loading angle, the larger the value. This is because the horizontal load component plays a dominant role. The compression of the piles above and below the loading point, as well as the bending moment, shear force and axial force under saturated sand conditions, are similar to those in dry sand, but their values are reduced by about 50%. It can be seen that the soil conditions have an influence on the bearing characteristics of pile foundations.

Abstract The pig-nosed turtle ( Carettochelys insculpta ) is an oviparous species with no parental care, so reproductive success depends on suitable nesting sites. This study examined nesting site selection and environmental factors influencing nest placement along a 28 km stretch of the Kao River, within the Mindipko Gemenop clan’s customary land. Fieldwork was conducted over eight weeks during the nesting season. Twenty-seven sandbanks were identified, but only 12 were used for nesting. Across these sites, researchers recorded 105 nests and 585 turtle tracks. Data collected at each nest included nest temperature, sand texture, position on the sandbank, depth, and diameter. Sandbank area and water level fluctuations were also recorded. Nests were mainly found in open areas with fine, dry sand on elevated contours, farther from the water’s edge. In 2022, nests had larger average diameters (15.45 cm), while in 2024 nests were deeper (21.26 cm). Temperatures were slightly higher in 2022, averaging ± 30 °C. These patterns align with previous studies and highlight the species’ preference for fine-scale microhabitat features when selecting nest sites. This study provides essential ecological insights into C. insculpta nesting behavior in Papua and emphasizes the importance of protecting key habitats along the Kao River.