Search Results (353)

Filling operations in pressurised pipeline systems can trap air pockets, generating hazardous transient overpressures that threaten structural integrity and operational reliability. Evaluating these events using conventional hydraulic models can be computationally intensive, limiting design-space exploration of operational scenarios. This study presents a simulation-driven design-screening framework based on Monte Carlo simulation to evaluate and predict peak absolute pressures during pipeline start-up and filling operations. A total of 2000 transient scenarios were generated for a representative 1100 m pipeline system by varying key geometric and operational parameters, including diameter, friction factor, column lengths, slopes, and reservoir elevation. Twenty-eight machine learning regression models were trained to develop a physics-informed surrogate model capable of rapidly predicting pressure peaks within the defined parameter domain. The trilayered neural network achieved the highest predictive accuracy, with robust validation (RMSE = 10.95 m, R² = 0.99) and test performance (RMSE = 9.78 m, R² = 0.99). Screening results showed that nominal pressure thresholds of 61.18 m and 407.89 m were exceeded in 97.53% and 4.89% of the retained peak-forming scenarios (n = 1746), respectively. The proposed framework provides an efficient and reproducible surrogate-based design-screening approach for transient overpressure risk within the evaluated hydraulic domain. Full article

Intrabasinal low uplifts in lacustrine rift basins are key targets for sedimentological and petroleum geological research, as they can act as local source areas and exert critical controls on intrabasinal “source-to-sink” systems. Due to the discontinuous sediment supply, these systems often demonstrate the subtle and intermittent nature, and their roles in the development of depositional systems are usually overlooked. To clarify the controlling effect of intrabasinal local provenances on sedimentary system evolution, this study reconstructed the dynamic tectonic evolution of the Weixinan Low Uplift in the Beibuwan Basin, and systematically analyzed its control on “source-to-sink” systems and sedimentary filling using integrated high-resolution 3D seismic, core, well logging and geochemical data. Our results demonstrate that the activity of Fault 3 dominated the paleogeomorphic evolution of the Weixinan Low Uplift and its surrounding areas, which further governed the spatiotemporal development of the “source-to-sink” system and the distribution of sedimentary systems, with distinct evolutionary stages as follows: During the Ls2 Member stage (48.6–40.4 Ma), Fault 3 was inactive, the Weixinan Low Uplift was manifested as a gently dipping subaqueous slope under the influence of regional lacustrine transgression, and only small-scale braided river deltas were developed on the slope belt with weak sediment supply from the Qixi Uplift. During the Ls1 Member stage (40.4–33.9 Ma), the Ls13 Sub-member stage (lower Ls1 Member stage) was characterized by initiation of Fault 3 with segmented activity, triggering the formation of the Eastern Sub-sag of the Haizhong Sag and subaqueous uplift of the Weixinan Low Uplift; clastic sediments from the central Qixi Uplift were transported northeastward, developed braided river deltas and large-scale basin-floor lacustrine fans. In the Ls12 Sub-member stage (middle Ls1 Member stage), Fault 3 continued to propagate and was gradually linked, leading to further uplift of the Weixinan Low Uplift and expansion of the Haizhong Sag; Clastic materials from the central Qixi Uplift were almost entirely trapped in the Eastern Sub-sag of the Haizhong Sag. During the Ls11 Sub-member stage (upper Ls1 Member stage), further intensification of Fault 3 activity caused the Weixinan Low Uplift to be subaerially exposed and evolve into an intrabasinal local provenance, which supplied clastic sediments to surrounding sags and developed braided river deltas on the gentle slope belts and small-scale lacustrine fans on the lower slope. This study demonstrates that the tectonic evolution of the Weixinan Low Uplift has induced prominent changes in the basin paleogeomorphology, which in turn triggered dynamic shifts in the provenance and sediment transport pathways, and thus gave rise to complex local “source-to-sink” systems and depositional styles. Full article

Transverse shear deformation plays a non-negligible role in lightweight periodic-core structures and motivates the use of shear-corrected reduced-order plate and beam models. However, the shear correction factor $k_s$ is often treated as a constant despite its strong dependence on cross-sectional heterogeneity and geometry. This work quantifies the global sensitivity of $k_s$ in corrugated paperboard by combining an energy-consistent pixel-based identification of the effective shear stiffness $\left(GA{)}_{\mathrm{e}\mathrm{f}\mathrm{f}}\right.$ with a space-filling exploration of the parameter domain. Representative three-ply (single-wall) and five-ply (double-wall) configurations are generated directly in the pixel domain using sinusoidal fluting descriptions and non-overlapping liner bands. The effective shear stiffness is obtained from a heterogeneous shear-energy equivalence, where a normalized two-dimensional shear-stress shape function is computed from pixel-based sectional descriptors and integrated with spatially varying shear moduli. Latin Hypercube Sampling is employed to explore wide ranges of flute period, height, and thickness, liner thicknesses, and liner–flute shear-modulus contrasts. Global sensitivity is reported using unit-free normalized indices, including log-elasticities (based on the slope of $\ln k_s$ versus $\ln x$) and partial rank correlation coefficients. The results demonstrate that flute geometry is the primary driver of $k_s$ variability, while material contrast significantly modulates shear-energy localization, particularly in double-wall boards with two distinct flutings. The proposed framework enables high-throughput shear correction assessment and supports robust parameterized reduced-order models for corrugated structures. Full article

With the rapid expansion of airport construction projects in China, high-fill airports are frequently built under complex geological conditions, where the high risk of surface stability may significantly affect flight safety and operational costs. In this study, 17 high-fill airports and 11 non-high-fill airports across China, all characterized by high subsidence risks, were selected to investigate vertical ground deformation. Utilizing multi-temporal Sentinel-1A radar imagery spanning from 2017 to 2024, Small Baseline Subset InSAR (SBAS-InSAR) was employed to retrieve the annual average deformation velocities and time-series cumulative displacements. The results revealed that among the selected sites, only 25% were relatively stable, while the others exhibited significant deformation characteristics. Notably, high-fill airports demonstrated greater deformation magnitudes compared to those in plain areas, especially in the area of prevalent slope subsidence. In addition, significantly positive correlation was found between fill height and deformation magnitude, while differential settlement was widespread in runway zones. Furthermore, foundations involving special ground conditions manifested continuedly and distinct deformation patterns despite ground treatments. This study demonstrates the limitations of current engineering approaches in completely eliminating airport deformation, and offers valuable insights for the site selection, engineering design, and maintenance of high-fill airports. Full article

Field data of high accuracy and precision is the basis for creating the high-quality design of a forest road. In this study, three survey methods for collecting field data were tested: ALS UAV, LiDAR data of the Republic of Croatia, collected by airplane, and UAV SfM. A total of three detailed forest road projects were created based on the collected data. The designed forest roads had the same horizontal and vertical development, thus eliminating the human factor from the design process. Four important forest road parameters were tested: earthwork cut and fill volume, cross-terrain slope, and carriageway value. No significant statistical difference was found for any of the tested parameters between designs. The design based on ALS data had a total number of earthworks of 1026.03 m³, the amount was 1449.56 m³ for SfM design, and the number of earthworks for the State Geodetic Administration LiDAR data was 889.02 m³. The calculated amount of cut volume was significantly affected by the error of the carriageway value for the State Geodetic Administration LiDAR data-based design. The results indicate the possibility of using all used methods on terrain with a moderate slope, but there is a need for further testing on different terrain slope classes. Full article

Understanding the crack development and rainfall infiltration in loess under wetting–drying cycles is crucial for assessing slope stability and promoting sustainable land management in ecologically vulnerable regions. This study employed a three-dimensional column model (Φ₂₄ × 50 cm) with 64 buried electrodes to simulate short-term heavy rainfall by changing the light duration (10 h/d and 5 h/d) and using 100 mm rainfall water. Results indicate that dry–wet cycles cause cumulative damage, significantly altering soil infiltration properties. After four cycles, the rainfall infiltration recharge coefficient increased from an initial 0.44% to 45.58%, a more than 100-fold rise. Resistivity imaging revealed a shift in water transport mode: from uniform matrix flow initially to preferential flow dominated by crack networks as cracks developed. During drying, crack zones exhibited high resistivity (ρ > 150 Ω·m), while water-filled cracks during infiltration showed low resistivity (ρ < 50 Ω·m). Resistivity is an excellent comprehensive index to quantify multi-field coupling damage, and its change (ρ∝ 1/w^1.86 × 1/(1 + 0.032 width)) synchronously responds to water content, crack development and dry–wet process. Low water content (w < 15%) and medium crack width (4–6 mm) are the most sensitive states. Longer illumination (10 h/d) promoted greater crack development and higher infiltration capacity compared to shorter cycles (5 h/d). The developed resistivity–moisture relationship provides a non-destructive monitoring tool for slope moisture dynamics, supporting not only geotechnical stability assessment but also optimized irrigation scheduling and adaptive land-use planning. These insights contribute directly to the sustainable management of soil and water resources in loess landscapes, aligning with sustainability goals in fragile ecosystems. Full article

The global ecological conditions are degrading rapidly, and even after the commitment to achieve Sustainable Development Goals by 2030, G7 countries still struggle to meet basic environmental standards. This study offers a novel marginal contribution by analyzing how economic globalization (EG), economic growth intensity (EGI), financial innovation (FI), and environmental technology (ET) influenced environmental degradation (ED) in the G7 countries from 2000 to 2021. Using the Method of Moments Quantile Regression (MMQR) alongside Driscoll and Kraay Standard Error (DKSE), this research provides a first-of-its-kind distributional mapping that accounts for cross-sectional dependency and heterogeneous slopes. Crucially, the findings reveal a “decoupling failure” in advanced economies, where the existing treatment mechanism for ET is insufficient to separate industrial growth from emissions due to institutional discrepancies. While FI is often viewed as a green catalyst, this study identifies it as a “double-edged sword,” showing that it significantly increases environmental degradation in higher quantiles due to carbon-intensive global supply chains. Conversely, EGI is discovered to be mitigatory, suggesting that enhancing financial efficiency and growth soundness can diminish ecological damage. This research fills a critical literature gap by reconciling the Pollution Haven Hypothesis and Green Finance Theory, providing empirical evidence that developed financial systems may inadvertently exacerbate damage if not specifically aligned with green mandates. Full article

Instability in dump slopes frequently induces landslides, a process governed by complex factors. To investigate the impact of gradation composition on dump slope stability, four distinct gradations were designed, and large-scale laboratory triaxial tests were conducted to characterize their strength and deformation behaviors under varying confining pressures. Concurrently, numerical models of dump slopes with these four gradations were established using Particle Flow Code (PFC) to simulate rainfall infiltration processes. Through a comparative analysis of particle contact force chains, pore water pressure evolution, particle displacement under varying rainfall durations, and safety factors under natural and rainfall conditions, the mechanisms governing the influence of gradation composition on slope stability were elucidated from both macroscopic and microscopic perspectives. Results indicate the following: (1) Gradation composition significantly affects the strength and deformation characteristics of dump materials. Sample group 3 (with a fine-to-coarse particle ratio of 4:6) exhibited the highest strength among the four test samples, with peak deviatoric stresses of 610 kPa, 1075 kPa, and 1539 kPa under confining pressures of 200 kPa, 400 kPa, and 600 kPa, respectively. Its corresponding shear strength parameters were a cohesion of 38.45 kPa and an internal friction angle of 32.55°. In contrast, sample group 4 (fine-to-coarse ratio of 6:4) showed the lowest strength, with peak deviatoric stresses of 489 kPa, 840 kPa, and 1290 kPa under the same confining pressures, and shear strength parameters of c = 25.35 kPa and φ = 30.02°. (2) Gradation modulates contact forces and failure modes via a “skeleton-filling” mechanism. (3) Gradation plays a critical role in controlling pore water pressure evolution and the seepage characteristics of the dump slope model. Among the four designed gradations and their corresponding numerical models, Model 3 was characterized by the highest contact forces and the lowest pore water pressure. It exhibited the highest stability under both natural and rainfall conditions, with safety factors of 1.70 and 1.22, respectively. Conversely, Model 4 showed weak particle contact forces and high pore pressure, demonstrating the poorest stability. It yielded safety factors of only 1.25 and 1.02 under natural and rainfall-saturated conditions, indicating that it represents the least favorable gradation composition. These findings provide valuable references for the optimization of dumping processes and stability control in similar engineering projects. Full article

Despite their ecological and conservation significance, morphometric relations remain scarce for elasmobranch species in the Mediterranean. This study examined morphometric parameters of the eight elasmobranch species (one shark and seven batoids) presented in the Amvrakikos Gulf that has been designated as a National Park. A total of 1247 specimens were sampled between 2022 and 2025, caught by small-scale fishing vessels using trammel nets, gillnets or bottom longlines and collected through onboard surveys or landing sites monitoring. Linear regressions were applied to describe relations between total length and other body measures (disc length, disc width, fork length), and length measurements and body weight. Results showed strong relations across morphometric traits, with R² values exceeding 0.655 for most relations. Growth patterns varied: four species (Aetomylaeus bovinus, Dasyatis pastinaca, D. tortonesei, Mustelus mustelus) exhibited positive allometry, one species (D. marmorata) displayed negative allometry and Gymnura altavela showed near-isometric growth. Sexual dimorphism was generally absent, although significant differences were found between sex in disc width slopes for D. marmorata, Myliobatis aquila and Torpedo torpedo, and in length–weight relations for M. mustelus. These findings substantially fill regional data gaps, offering new baseline estimates for rare and threatened elasmobranchs. Full article

In arid open-pit mines, rainfall-triggered slope instability presents significant risks, but quantitative thresholds are poorly defined due to limited integration of transient seepage and stability in low-permeability soils. This study fills this gap by using GeoStudio’s SEEP/W and SLOPE/W modules to simulate rainfall effects on a moderately steep-slope (51° average) limestone mine slope in Ningxia’s Kazimiao Mining Area (annual precipitation: 181.1 mm). The novelty lies in identifying a 12 h saturation window under intense rainfall (≥100 mm h⁻¹), during which pore water pressure stabilizes as soil reaches saturation, creating an “infiltration buffering effect” driven by arid soil properties (hydraulic conductivity: 2.12 × 10⁻⁴ cm s⁻¹). Results show that the factor of safety (FOS) drops sharply within 12 h (e.g., from 1.614 naturally to 1.010 at 200 mm h⁻¹) and then stabilizes, with FOS remaining >1.05 (basically stable) under rainfall intensities ≤ 50 mm h⁻¹, but drops into the less-stable range (1.00–1.05) at 100–200 mm h⁻¹, reaching marginal stability (FOS ≈ 0.98–1.02) after 24 h of extreme events, according to GB/T 32864-2016. Slope protection measures increase FOS (e.g., 2.518 naturally). These findings quantify higher instability thresholds in arid compared to humid regions, supporting regional guidelines and informing early-warning systems amid climate-related extremes. This framework enhances sustainable slope management for mines worldwide in arid–semi-arid zones. Full article

Riverbank erosion is a significant natural disaster that is prevalent in the deltaic regions in Bangladesh, resulting in loss of land, crops, and settlements. This research work is concentrated on the Satkhira Koyra area and is oriented towards a comparative assessment of the functionality of geo-bag and cement concrete (CC) blocks for erosion control purposes. The results showed that a geogrid could be used on the riverbank slope for more soil stability. The proposed approach is that the geogrid is used as a base layer for the slope. The sand-filled geo-bags are more cost-effective with this combination. Field monitoring and hydraulic model testing were used to identify their performance under natural flow conditions. Lined with geotextile fabric and filled with sand, the geo-bags were located in the most susceptible riverbank areas. The empirical results showed that the geo-bags provide the same levels of hydraulic resistance as those provided by CC blocks, but with substantial economic benefits and installation accomplished by local labor. When used in combination with a geogrid base layer, the geo-bag construction ensured excellent slope stability and allowed the establishment of natural vegetation, thus contributing to an environmentally friendly restoration. While CC blocks remain the optimal solution for high-value structures, the combined geogrid and geo-bag system offers a more flexible, cost-effective, and environmentally friendly alternative for stable erosion protection. Full article

This study systematically investigates the post-construction settlement behavior of high-fill red clay embankments, focusing on the influences of three key factors (water content, degree of compaction, and lift thickness) and the effectiveness of geogrid-based reinforcement measures. A three-dimensional finite-element model based on the Mohr–Coulomb constitutive theory was established using MIDAS GTS NX 2022 R1 to simulate staged construction processes and long-term settlement under self-weight loading. The results indicate that settlement is predominantly concentrated in the upper fill zone adjacent to the slope surface, with displacement contours sagging inward toward the fill interior, while the underlying foundation undergoes negligible deformation. An elevated water content and reduced degree of compaction significantly enhance the compressibility of red clay, leading to increased settlement magnitudes and prolonged stabilization periods. Excessively thick lifts result in inadequate deep compaction, thereby inducing larger final settlements. Two reinforcement schemes (geogrid combined with anti-slide piles and geogrid combined with a gravity retaining wall) were verified to effectively mitigate post-construction settlement, with the former achieving a more pronounced improvement in the embankment stability coefficient. Based on the comprehensive analysis, optimal construction control parameters for high-fill red clay embankments are proposed: precise regulation of water content, maximization of compaction degree, and adoption of a lift thickness of approximately 30 cm. The findings of this study provide quantitative technical support and design references for the settlement control of similar high-fill red clay embankment projects in southern China’s mountainous and hilly regions. Full article

Computational modeling offers a cost-effective approach to exploring complex geotechnical behavior. This study uses PLAXIS 2D finite element software to simulate nailed soil slopes under plane strain conditions, with models calibrated against laboratory-scale experiments involving a sand-filled Perspex box, steel nail reinforcements, and a rigid foundation. The soil mass, structural elements, and reinforcements are modeled using fifteen-node triangular elements, five-node plate elements, and two-node elastic spring elements, respectively. In this paper, parametric studies evaluate the influence of slope angles, mesh density, domain dimensions, constitutive models, and reinforcement configurations. Both prototype-scale and 3D-approximated models are included to assess scale effects and spatial behavior. The results highlight the significant impact of model size and material behavior, particularly when using the Hardening Soil model and its small-strain extension. Reinforcement optimization, including nail length reduction strategies, demonstrates the potential for maintaining slope stability while improving material efficiency. Validation against experimental data confirms that the numerical models accurately capture deformation patterns and internal stress development across different construction and loading phases. This study observed that the Hardening Soil (small-strain) material model significantly improved slope performance by reducing settlements and better capturing stress behavior, especially for steep slopes. Optimized redistribution of nail lengths across the slope depth enhanced stability while reducing reinforcement usage, demonstrating a cost-effective alternative to uniform configurations. The findings offer practical guidance for optimizing nailed slope stabilization in sandy soils, supporting safer and more economical geotechnical design for real-world applications. Full article

The Qinba Mountains in China span six provinces, characterized by a large population, rugged terrain, steep peaks, deep valleys, and scarce flat land, making large-scale agricultural development challenging. Terraced fields serve as the core cropland type in this region, playing a vital role in preventing soil erosion on sloping farmland and expanding agricultural production space. They also function as a crucial medium for sustaining the ecosystem services of mountainous areas. As a transitional zone between China’s northern and southern climates and a vital ecological barrier, the Qinba Mountains’ terraced ecosystems have undergone significant spatial changes over the past two decades due to compound factors including the Grain-for-Green Program, urban expansion, and population outflow. However, current large-scale, long-term, high-resolution monitoring studies of terraced fields in this region still face technical bottlenecks. On one hand, traditional remote sensing interpretation methods rely on manually designed features, making them ill-suited for the complex scenarios of fragmented, multi-scale distribution, and terrain shadow interference in Qinba terraced fields. On the other hand, the lack of high-resolution historical imagery means that low-resolution data suffers from insufficient accuracy and spatial detail for capturing dynamic changes in terraced fields. This study aims to fill the technical gap in detailed dynamic monitoring of terraced fields in the Qinba Mountains. By creating image tiles from Landsat-8 satellite imagery collected between 2017 and 2020, it employs three deep learning semantic segmentation models—DeepLabV3 based on ResNet-34, U-Net, and PSPNet deep learning semantic segmentation models. Through optimization strategies such as data augmentation and transfer learning, the study achieves 15-m-resolution remote sensing interpretation of terraced field information in the Qinba Mountains from 2000 to 2020. Comparative results revealed DeepLabV3 demonstrated significant advantages in identifying terraced field types: Mean Pixel Accuracy (MPA) reached 79.42%, Intersection over Union (IoU) was 77.26%, F1 score attained 80.98, and Kappa coefficient reached 0.7148—all outperforming U-Net and PSPNet models. The model’s accuracy is not uniform but is instead highly contingent on the topographic context. The model excels in environments that are archetypal for mid-altitudes with moderately steep slopes. Based on it we create a set of tiles integrating multi-source data from RBG and DEM. The fusion model, which incorporates DEM-derived topographic data, demonstrates improvement across these aspects. Dynamic monitoring based on the optimal model indicates that terraced fields in the Qinba Mountains expanded between 2000 and 2020: the total area was 57.834 km² in 2000, and by 2020, this had increased to 63,742 km², representing an approximate growth rate of 8.36%. Sichuan, Gansu, and Shaanxi provinces contributed the majority of this expansion, accounting for 71% of the newly added terraced fields. Over the 20-year period, the center of gravity of terraced fields shifted upward. The area of terraced fields above 500 m in elevation increased, while that below 500 m decreased. Terraced fields surrounding urban areas declined, and mountainous slopes at higher elevations became the primary source of newly constructed terraces. This study not only establishes a technical paradigm for the refined monitoring of terraced field resources in mountainous regions but also provides critical data support and theoretical foundations for implementing sustainable land development in the Qinba Mountains. It holds significant practical value for advancing regional sustainable development. Full article

To investigate the soil displacement rule caused by shield tunneling in soil–rock composite strata, the convergence mode of the shield excavation surface was analyzed. The research accounts for the variations in the slopes of the tunnel and the rock–soil interface along the excavation direction. Based on the stochastic medium theory, the calculation formula of soil displacement under different depths is derived. Surface subsidence was computed and evaluated using three engineering case studies. The results show that the calculated surface subsidence curves exhibit strong symmetry and are similar to the distribution pattern of the measured data. When tunneling through composite strata, the segments are prone to an upward floating motion, leading to a convergence pattern in the cross-section that tends toward a non-equal radial convergence mode with top tangency. Within the same project context, the grouting filling rate (δ) diminishes as the hard rock ratio (B) increases, exhibiting an approximate linear correlation. An increase in the hard rock ratio results in reduced values for lateral and longitudinal subsidence, the width of the lateral subsidence trough, and the main impact zone of the shield tunneling operations. Full article