Search Results (85)

Siziwang Banner in Inner Mongolia is a typical arid and semi-arid grassland region where ecological environmental quality is highly sensitive to climate variability and land use and land cover change (LULCC). Clarifying the long-term coupling relationship between LULCC and ecological environmental quality is essential for regional ecological protection and sustainable land management. Based on the Google Earth Engine (GEE) platform, this study integrated multi-temporal Landsat imagery and CLCD-based land use datasets, including an updated 2024 land use layer, to construct a Remote Sensing Ecological Index (RSEI) using standardized and direction-corrected principal component analysis. land use transition matrix analysis, spatial autocorrelation analysis, ecological contribution rate calculation, and GeoDetector were further applied to reveal the spatiotemporal evolution patterns, ecological effects, and driving mechanisms of LULCC in Siziwang Banner from 2000 to 2024. The results showed that: (1) grassland was consistently the dominant land use type, accounting for more than 90% of the total area. The overall land use pattern was characterized by stable grassland dominance, decreasing farmland and unused land, and slight increases in grassland and construction land; forestland showed a high relative growth rate but remained very small in absolute area. (2) The regional ecological environmental quality remained at a lower-to-medium level, with mean RSEI values ranging from 0.27 to 0.47. RSEI showed a phased pattern of initial improvement, subsequent decline, and partial recovery; the marked decline around 2015 was associated with the combined effects of drought stress and land use degradation rather than a single driving factor. RSEI exhibited significant positive spatial autocorrelation, with Moran’s I values ranging from 0.898 to 0.993. High-value clusters were mainly distributed in the southern region, whereas low-value clusters were concentrated in the central and northern regions. (3) Different land use transitions produced differentiated ecological effects. The conversion of unused land to grassland contributed positively to ecological restoration, while grassland degradation and construction land expansion exerted negative effects. The positive RSEI response of some grassland-to-farmland transitions should be interpreted cautiously in relation to local irrigation and intensive farmland management. (4) GeoDetector results indicated that land use type and DEM were the dominant factors controlling the spatial differentiation of RSEI, with average q values of 0.7188 and 0.6178, respectively. The interaction between DEM and land use type showed the strongest explanatory power, indicating that ecological quality was jointly shaped by land use structure and natural background conditions. This study provides a scientific basis for grassland protection, unused-land restoration, farmland management, and spatially differentiated ecological restoration in Siziwang Banner and similar ecologically fragile arid and semi-arid grassland regions. Full article

The accurate characterization and geo-localization of objects using image data and LiDAR are important for forestry, agriculture, urban planning, infrastructure monitoring, and related geospatial applications. However, reliability is affected by uncertainty introduced during sensor acquisition, LiDAR-image projection, segmentation, object-parameter estimation, and final geo-localization. This paper presents a proof-of-concept and method prototype for an uncertainty-aware LiDAR-image workflow in a forestry setting. The novelty of the work does not lie in proposing a new segmentation architecture, but in integrating image-based segmentation, LiDAR-image projection, DBH-level geometric estimation, stage-wise uncertainty propagation, and uncertainty-aware reconciliation of alternative estimates within a single modular workflow. The experimental evaluation was conducted on a limited pilot dataset consisting of 12 individual trees, multiple LiDAR acquisition viewpoints, and 18 high-resolution photographs. The number of trees is the number of independent analyzed objects, whereas the scans and photographs represent acquisition observations. Dense LiDAR point clouds provide many object-level geometric measurements, but these points are not interpreted as independent biological samples. Under the tested acquisition and processing conditions, the uncertainty-aware reconciliation step reduced the estimated spatial uncertainty to approximately 2.5 ± 0.4 cm. This value should be interpreted as a pilot result for the analyzed dataset, not as a general performance guarantee across forest types, tree species, stand densities, lighting conditions, or occlusion patterns. The contribution of this study is therefore positioned as a modular engineering-oriented uncertainty propagation and reconciliation workflow for DBH-level forestry localization. Potential use in robotics, infrastructure monitoring, or other high-precision geospatial applications is discussed only as a future direction requiring separate validation, larger datasets, and real-time implementation work. Full article

Simple shear testing is a widely used method in geotechnical engineering for evaluating soil liquefaction susceptibility, deformation characteristics, and shear strength under controlled loading conditions. This study presents a bibliometric analysis of research trends in simple shear testing based on 367 publications indexed in the Scopus database between 2000 and 2024, analyzed using VOS-viewer. It appears that the current research output on this topic has greatly increased lately. The number of research articles reached a peak in 2024 with a total of 42 research articles. The most frequently cited journals on this topic are Soil Dynamics and Earthquake Engineering, with a total of 48 research articles (1173 citations); the Journal of Geotechnical and Geo-environmental Engineering, with a total of 34 research articles (772 citations); and the Canadian Geotechnical Journal, with a total of 10 research articles (250 citations). This indicates substantial research interest in earthquake engineering and soil mechanics. The output shows that there is a major emphasis on research done in the USA, with a total of 104 research articles (1215 citations). The highest average citations per document belong interestingly to the research done by Taiwanese, with a total of 36.73 citations. Similarly, it appears that there is a good impact on soil liquefaction studies. The research findings show that confining pressure, strain rates, and volume ratio affect the shear strength of the soil. Advances in boundary control and shear testing techniques have improved the reliability of experimental results. The study underscores the growing need for more sophisticated numerical modeling techniques and field verification to bridge the gap between laboratory findings and real geotechnical applications. These findings contribute to improving soil characterization methods, which enable safer and more efficient geotechnical designs for infrastructure development. Full article

The shear strength of rock discontinuities is critical for the stability of deep underground projects. However, its accurate determination is hindered by the discreteness of natural joints and the limitations of conventional direct shear tests, which operate under simplified two-dimensional stress conditions, unlike the true triaxial (σ₁ > σ₂ > σ₃) in situ state. This study introduces and validates a multistage true triaxial direct shear testing method as a practical solution. Through controlled pre-peak unloading, complete failure envelopes were successfully obtained from single specimens of jointed granite and intact marble with minimal strength degradation. The results demonstrate that lateral stress significantly enhances the peak shear strength, characterized by a marked increase in cohesion coupled with a slight decrease in the internal friction angle. For intact marble, increasing the lateral stress from 0 to 20 MPa raised the cohesion by approximately 67% (from 34.9 to 58.4 MPa), while the friction angle decreased from 49.3° to 42.8°. For jointed granite, cohesion showed a more variable but consistently strengthening trend with confinement, accompanied by a minor adjustment in the friction angle. Acoustic emission monitoring confirms that pre-peak unloading confines damage accumulation to microcrack reactivation. From a fracture mechanics perspective, the strength enhancement is attributed to the suppression of tensile crack propagation and the promotion of shear localization under three-dimensional confinement. Collectively, this work establishes a novel experimental framework and elucidates the mechanism by which lateral stress governs the shear behavior of hard rock, offering direct implications for the design and stability assessment of deep excavations and related geo-engineering projects. Full article

The deep formations (burial depth: 3500–4000 m) in the northern Luzhou Block boast favorable geological conditions for shale gas accumulation. However, field development is hindered by the frequent casing deformation of shale gas wells and significant variations in single-well productivity. These issues severely restrict the efficient development of shale gas resources. Existing studies mainly focus on the identification and optimization of geo-engineering dual sweet spots, but few have established a systematic and comprehensive evaluation system from the perspective of engineering risk prevention and control. Based on traditional research on geo-engineering dual sweet spots, this study integrates engineering risk factors. It innovatively establishes a geo-engineering dual sweet spot evaluation system that incorporates engineering risks. Four key evaluation indicators for shale matrix geo-engineering sweet spots are selected: the continuous thickness of a Class I reservoir, the structural location, the fault scale, and natural fracture characteristics. Accordingly, shale matrix geo-engineering sweet spots are classified into three categories: Class I-A Area, Class I-B Area, and Class II Area. Meanwhile, three key indicators affecting fault slip—the angle between fractures and the maximum horizontal in situ stress direction, fracture dip angle, and friction coefficient—are optimized to establish the fault slip risk evaluation criteria. Combined with the distribution characteristics of slip faults, the engineering risks are divided into three levels: high, medium, and low. Finally, by coupling the geo-engineering sweet spots of a shale matrix with engineering risk zones, the geo-engineering sweet spots of shale reservoirs in the study area are classified into four categories (I, II, III, IV). Full article

As a cornerstone of China’s energy infrastructure, the coal mining industry relies heavily on the stability of its underground roadways, where the support of soft rock formations presents a critical and persistent technological challenge. This challenge arises primarily from the high content of expansive clay minerals and well-developed micro-fractures within soft rock, which collectively undermine the effectiveness of conventional support methods. To address the soft rock control problem in China’s Longdong Mining Area, an integrated material–structure control approach is developed and validated in this study. Based on the engineering context of the 3205 material gateway in Xin’an Coal Mine, the research employs a combined methodology of micro-mesoscopic characterization (SEM, XRD), theoretical analysis, and field testing. The results identify the intrinsic instability mechanism, which stems from micron-scale fractures (0.89–20.41 μm) and a high clay mineral content (kaolinite and illite totaling 58.1%) that promote water infiltration, swelling, and strength degradation. In response, a novel synergistic technology was developed, featuring a high-performance grouting material modified with redispersible latex powder and a tiered thick anchoring system. This technology achieves microscale fracture sealing and self-stress cementation while constructing a continuous macroscopic load-bearing structure. Field verification confirms its superior performance: roof subsidence and rib convergence in the test section were reduced to approximately 10 mm and 52 mm, respectively, with grouting effectively sealing fractures to depths of 1.71–3.92 m, as validated by multi-parameter monitoring. By integrating microscale material modification with macroscale structural optimization, this study provides a systematic and replicable solution for enhancing the stability of soft rock roadways under demanding geo-environmental conditions. Soft rock roadways, due to their characteristics of being rich in expansive clay minerals and having well-developed microfractures, make traditional support difficult to ensure roadway stability, so there is an urgent need to develop new active control technologies. This paper takes the 3205 Material Drift in Xin’an Coal Mine as the engineering background and adopts an integrated method combining micro-mesoscopic experiments, theoretical analysis, and field tests. The soft rock instability mechanism is revealed through micro-mesoscopic experiments; a high-performance grouting material added with redispersible latex powder is developed, and a “material–structure” synergistic tiered thick anchoring reinforced load-bearing technology is proposed; the technical effectiveness is verified through roadway surface displacement monitoring, anchor cable axial force monitoring, and borehole televiewer. The study found that micron-scale fractures of 0.89–20.41 μm develop inside the soft rock, and the total content of kaolinite and illite reaches 58.1%, which is the intrinsic root cause of macroscopic instability. In the test area of the new support scheme, the roof subsidence is about 10 mm and the rib convergence is about 52 mm, which are significantly reduced compared with traditional support; grouting effectively seals rock mass fractures in the range of 1.71–3.92 m. This synergistic control technology achieves systematic control from micro-mesoscopic improvement to macroscopic stability by actively modifying the surrounding rock and optimizing the support structure, significantly improving the stability of soft rock roadways. Full article

One of the main application areas for treatments modifying the filtration properties of porous rocks, besides improving the sealing of landfills, reducing water hazards in mine workings, and eliminating water permeability in geoengineering works, is hydrocarbon exploitation. Among the available solutions, chemical methods are considered most effective, using treatment fluids injected into water-bearing layers. The decision to perform a modification treatment using a particular treatment fluid must, in each case, be preceded by a laboratory simulation of its technological effectiveness. This article presents research aimed at developing a methodology for reliable evaluation of treatment fluids used to modify the filtration properties of porous rocks. In addition to standard flood tests, additional methods were applied, notably X-ray computed tomography, which enabled non-destructive visualization of gel barriers in rock pores. Microscopic analysis of thin sections also supported pore space characterization. Research conducted on sandstone samples with the Multizol treatment fluid, developed at the Oil and Gas Institute—National Research Institute, confirmed the outcomes of flood tests and Residual Resistance Factor (F_RR) calculations. Integration of all the results enhanced the reliability of the effectiveness assessment, which may be crucial for optimizing performed treatments, especially under the variable geological conditions and petrophysical parameters of rocks of the near-wellbore zone. Full article

In the field of geoengineering, predicting foundation settlement is a critical topic. Traditional settlement prediction methods struggle to accurately reflect settlement under complex geological conditions. This study combines cone penetration test (CPT) data and collects data from 46 different geoengineering sites from the literature. Gradient Boosting Decision Tree (GBDT), Extreme Gradient Boosting (XGBoost), Deep Neural Network (DNN), Support Vector Machine (SVM), and Random Forest (RF) models are individually established, and an ensemble model is proposed to predict shallow foundation settlement St. The results show that the proposed ensemble model exhibits the best predictive performance, providing a reference for practical engineering projects. The predictions of the optimal model are compared with those of single models and traditional methods, and the uncertainty of model predictions is quantified using Monte Carlo Simulation (MCS). Sensitivity analyses are conducted using feature importance analysis and SHAP methods to assess the influence of input parameters on the prediction results. Finally, Generative Adversarial Networks (GANs) are introduced to generate new data to validate the generalization capability of the model. Full article

This paper systematically investigates the interaction between pipes and soil under geo-logical disaster conditions by combining small-scale physical experiments with mul-ti-method numerical simulations. Three analytical models—namely the Smoothed Particle Hydrodynamics-Finite Element Method (SPH-FEM) model, the traditional FEM model, and the soil spring-based Pipe–Soil Interaction (PSI) model—are employed to comparatively analyze their applicability across different geohazard scenarios. The study found that the PSI model overpredicted pipeline strain responses, indicating that traditional soil spring analytical models require modification. The traditional FEM model provided the most accurate predictions under small-displacement conditions, while the SPH-FEM model yielded more reliable results for large-displacement scenarios. The novelty of this study lies in its systematic exploration of the applicability of these three methodologies, providing scientifically grounded simulation tools for numerical modeling in engineering practice. Full article

Injecting carbon dioxide (CO₂) into underground geo-structures, such as depleted oil and gas reservoirs, reduces man-made CO₂ emissions into the atmosphere or removes what is already there. Studies have identified the risks of CO₂ leaks from these underground geo-structures through wellbores back into the atmosphere due to the high mobility of CO₂ in gaseous and supercritical states. This work aims at proposing a novel method of CO₂ storage using the Joule–Thomson cooling effect to effectively produce CO₂ hydrates on seafloors, with an objective to avoid the leakage risks of storage in depleted oil and gas reservoirs. Through the combination of thermodynamic data, analysis of hydrate stability, and engineering design with established working parameters, this study proposes an innovative concept and an enabling process for CO₂ placement onto seafloors for safe storage. The results of case analysis of typical seawater conditions reveal that the appropriate seafloor depth ranges for different applications (>1900 m for liquid CO₂ and 700–1900 m for CO₂ hydrate). An engineering design procedure for real applications is outlined. Full article

Relying on an engineering case, this study establishes an analysis model using PLAXIS 3D and GeoStudio, and compares and analyzes the slope deformation and internal force of the supporting structure with different slope grades and different platform widths at the same height. The results show that the greatest displacement manifests in the lower segments of the slope, which is 12.99 mm, and the maximum anchoring force manifests in the mid-level and lower segments of the slope, which is 288.1 kN. A close correlation is observed between the simulated horizontal displacement of the slope, the maximum axial force of the anchor cable, and the corresponding field measurement results, indicating that the model parameters are satisfactory and that the resulting calculations are reliable. In consideration of the comprehensive stability of the slope, the stability coefficient increased by approximately 1.42% with two-stage slope support and by about 3.48% with four-stage slope support. The axial force of anchor cables was reduced by around 9.5% under two-stage grading, while four-stage grading decreased the maximum axial force of the middle–lower anchors by nearly 27%. The distance between the entrance and exit of the overall sliding surface and the slope surface also decreases with the increase in slope grading and platform width. This study systematically evaluates the combined effects of slope grading, platform width, and frame prestressed anchors. When site conditions permit, slope grading should be prioritized over simply widening the platform, as grading more effectively enhances slope stability and reduces anchor cable loads. Full article

Optimal airfoil design remains a critical challenge in aerodynamic engineering, with traditional methods requiring extensive computational resources and iterative processes. This paper presents GEO-DSGA, a novel framework integrating hybrid geometric neural networks with deep symbiotic genetic algorithms for enhanced airfoil optimization. The methodology employs graph-based representations of airfoil geometries through a hybrid architecture combining graph convolutional networks with traditional deep learning, enabling precise capture of spatial geometric relationships. The parametric modeling stage utilizes CST, Bézier curves, and PARSEC methods to generate mathematically robust airfoil representations, subsequently transformed into graph structures preserving local and global shape characteristics. The optimization framework incorporates a deep symbiotic genetic algorithm enhanced with dominant feature phenotyping, applying biological symbiotic principles where design parameters achieve superior performance through mutual enhancement rather than independent optimization. This systematic exploration maintains geometric feasibility and aerodynamic validity throughout the design space. Experimental results demonstrate an 88.6% reduction in computational time while maintaining prediction accuracy within 1.5% error margin for aerodynamic coefficients across diverse operating conditions. The methodology successfully identifies airfoil geometries outperforming baseline NACA profiles by up to 12% in lift-to-drag ratio while satisfying manufacturing and structural constraints, establishing GEO-DSGA as a significant advancement in computational aerodynamic design optimization. Full article

As global temperatures continue to rise despite international mitigation efforts, geoengineering has emerged as a potential avenue for climate intervention. One of the most promising and ambitious concepts is the Planetary sunshade—a large-scale structure located at Lagrange Point L1, designed to reduce solar irradiance by physically blocking or redirecting incoming photons. This paper presents a structural design solution for this ambitious system, focusing on deployable mechanisms, frame architecture, and sail configurations that enable rapid mass production and deployment of solar sails components. The design process follows the European Cooperation for Space Standardization (ECSS) methodology through its early-phase stages, utilizing weighted decision matrices for concept selection and material evaluation. Finite element analysis (FEA) was used to validate structural integrity under Atlas V launch and operational conditions. The final design features a 1297 m² sail composed of four triangular segments, deployed via booms and stowed using a vertical folding pattern around a central spool. The booms incorporate arch-shaped cross-sections to enhance stiffness. This configuration achieves a radius expansion ratio of 25 and a sail efficiency factor of 0.5, ensuring survivability under Atlas V launch loads. Full article

The development of mining operations in high-altitude regions is associated with a number of geomechanical challenges caused by increased rock fracturing, adverse climatic conditions, and high seismic activity. These issues are particularly relevant for the exploitation of gold ore deposits, where the stability of open-pit slopes directly affects both safety and extraction efficiency. The aim of this study is to develop and practically substantiate a comprehensive approach to assessing and ensuring slope stability, using the Bozymchak gold ore deposit—located in a high-altitude and seismically active zone—as a case study. The research involves the laboratory testing of rock samples obtained from engineering–geological boreholes, field shear tests on rock prisms, laser scanning of pit slopes, and digital geomechanical modeling. The developed calculation schemes take into account the structural features of the rock mass, geological conditions, and the design contours of the pit. In addition, special bench excavation technologies with pre-shear slotting and automated GeoMoS monitoring are implemented for real-time slope condition tracking. The results of the study make it possible to reliably determine the strength characteristics of the rocks under natural conditions, identify critical zones of potential collapse, and develop recommendations for optimizing slope parameters and mining technologies. The implemented approach ensures the required level of safety. Full article

CO₂ geo-storage is a promising approach in reducing greenhouse gas emissions and controlling global temperature rise. Although numerous studies have reported that offshore saline aquifers have greater storage potential and safety, current suitability evaluation models for CO₂ geo-storage primarily focus on onshore saline aquifers, and site-level evaluations for offshore CO₂ geo-storage remain unreported. In this study, we propose a framework to evaluate the site-level offshore CO₂ geo-storage suitability with a multi-tiered indicator system, which considers three types of factors: engineering geology, storage potential, and socio-economy. Compared to the onshore CO₂ geo-storage suitability evaluation models, the proposed indicator system considers the unique conditions of offshore CO₂ geo-storage, including water depth, offshore distance, and distance from drilling platforms. The Analytic Hierarchy Process (AHP) and Fuzzy Comprehensive Evaluation (FCE) methods were integrated and applied to the analysis of the Ying–Qiong Basin, South China Sea. The results indicated that the average suitability score in the Yinggehai Basin (0.762) was higher than that in the Qiongdongnan Basin (0.691). This difference was attributed to more extensive fault development in the Qiongdongnan Basin, suggesting that the Yinggehai Basin is more suitable for CO₂ geo-storage. In addition, the DF-I reservoir in the Yinggehai Basin and the BD-A reservoir in the Qiongdongnan Basin were selected as the optimal CO₂ geo-storage targets for the two sub-basins, with storage potentials of 1.09 × 10⁸ t and 2.40 × 10⁷ t, respectively. This study advances the methodology for assessing site-level potential of CO₂ geo-storage in offshore saline aquifers and provides valuable insights for engineering applications and decision-making in future CO₂ geo-storage projects in the Ying–Qiong Basin. Full article