Geomechanics for Energy and the Environment最新文献

{"title":"A data-driven analysis of changes in volumetric and hydraulic properties of rocks under the presence of hydrogen","authors":"Eftychia Christodoulou ,&nbsp;Charalampos Konstantinou ,&nbsp;Panos Papanastasiou","doi":"10.1016/j.gete.2026.100805","DOIUrl":"10.1016/j.gete.2026.100805","url":null,"abstract":"<div><div>Underground hydrogen storage (UHS), considered a viable solution for large-scale storage, raises concerns about the integrity and performance of reservoir and caprock formations under hydrogen exposure. This study investigates the volumetric and hydraulic properties alterations of different type of rocks under the influence of hydrogen, through data-driven analysis by employing the random forest (RF) algorithm, a machine learning (ML) technique. Data have been collected from the existing literature which relate to porosity and permeability changes and calculation of hydrogen diffusion coefficients after the rock formations have been exposed to hydrogen. Variables such as the initial rock properties, type of rocks and environmental conditions are included as features in the ML models. For porosity and permeability, the most influential factors found, are the type of rock and its initial porosity and permeability values, with low-porosity rocks like shales showing higher sensitivity to hydrogen exposure, especially under high pressure (&gt;10 MPa) and high temperature (&gt;100°C). Based on the measurements, a unified Kozeny-Carman type equation across lithologies is derived, which can be used in reservoir mathematical models. In predicting hydrogen diffusion, initial porosity, pressure, and hydrogen concentration were the most important variables, with strong interactions observed between porosity and insitu conditions such as pressure, temperature and hydrogen exposure duration. Based on the feature importance results, the Chapman-Enskog equation was also fitted to the data to predict diffusivity, primarily for sandstone formations, and could also be used for modelling. The findings highlight clear gaps in the existing experimental literature and indicate the need for additional laboratory studies targeting under-represented combinations of operating conditions.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100805"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Finite element analysis of shear stress evolution in fault-related folds: implications for subsurface geomechanics and energy applications","authors":"Anis Khalifeh-Soltani ,&nbsp;Mehdi Ganjiani ,&nbsp;Reza Derakhshani","doi":"10.1016/j.gete.2026.100813","DOIUrl":"10.1016/j.gete.2026.100813","url":null,"abstract":"<div><div>Fault-related folds are critical subsurface structures that strongly influence fluid flow, reservoir integrity, and fault stability in a wide range of energy and environmental applications. Reliable predictions of their mechanical behavior are essential for assessing risks associated with hydrocarbon production, geothermal operations, carbon storage, and induced seismicity. In this study, we employ two-dimensional finite element models to quantify the evolution of shear stress component in three end-member fold types—detachment, fault-propagation, and fault-bend folds. Stress–time histories extracted from representative elements on fold surfaces and fault planes reveal systematic spatiotemporal patterns. The results show that (i) maximum shear stresses localize at fault tips and fold forelimbs, whereas minima occur near detachment terminations and fold crests; (ii) layer buckling enhances shear stress magnitudes and reorients principal stress axes, promoting strain localization; and (iii) shear stresses consistently peak at ∼45° to bedding, independent of fold rotation. These findings provide new quantitative insights into the mechanical evolution of fault-related folds and offer practical guidance for geomechanical modeling strategies in subsurface energy and environmental applications.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100813"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Impact of pore-water salinity and sulphate concentration on the breakdown pressure of limestone rocks","authors":"Mohammad Rezaee,&nbsp;Mohsen Masihi,&nbsp;Hassan Mahani","doi":"10.1016/j.gete.2025.100781","DOIUrl":"10.1016/j.gete.2025.100781","url":null,"abstract":"<div><div>Hydraulic fracturing (HF) is widely used to enhance production from subsurface energy systems, with fracturing pressure governed by geochemical and geomechanical factors. While similar rock types and stress conditions may exist across regions, rock-pore water interactions can vary, influencing fracture behavior. A key factor overlooked in current models is sulphate ion variability in pore water, which interacts with carbonate rock and alters its mechanical properties. This study investigates how sulphate concentration in the formation water affects HF in limestone rock, using laboratory-scale experiments and theoretical modeling. A custom-built 2D fracturing apparatus was used to evaluate breakdown pressure (BP) dependency on sulphate concentration and injection rate. Additional insights were obtained through surface complexation modeling, disjoining pressure calculations, microscopic imaging, and elemental analysis. Results indicate that BP increases with injection rate, facilitating smoother, more effective fractures. The primary weakening mechanism arises from alterations in intergranular forces due to brine composition changes, rather than mineral dissolution or precipitation. Salinity affects BP by modifying both rock tensile strength and local stress state. Notably, BP exhibits a non-monotonic trend with sulphate concentration, reaching maximum weakening at 1 M salinity. High salinity results in lower BP, leading to irregular, less conductive fractures, while lower sulphate levels enhance injectivity post-HF, improving reservoir performance. These novel findings provide critical insights for optimizing HF and injection operations, particularly when brine salinity differs from formation water, enabling more effective well stimulation strategies in carbonate reservoirs.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100781"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A multi-method integration approach for determining draw angles in underground metal mining: A case study of the kuogeshaye gold mine","authors":"Jiahui Tian ,&nbsp;Ruiyang Bi ,&nbsp;Jian Zhou ,&nbsp;Zupu Xuan ,&nbsp;Kun Du","doi":"10.1016/j.gete.2025.100777","DOIUrl":"10.1016/j.gete.2025.100777","url":null,"abstract":"<div><div>Accurate determination of the draw angle is critical for defining surface subsidence boundaries and ensuring the safety of surface infrastructure during mining operations. To overcome the limitations of single-method approaches, this study proposes a multi-method integration framework. Using the Kuogeshaye Gold Mine as a case study, the framework effectively combines theoretical calculation, particle swarm optimization–support vector machine prediction, and numerical simulation. The maximum relative error between the results achieved using the three methods was only 5.1 %. Additionally, an analytic hierarchy process-based weighted fusion strategy was used to integrate the results from the three methods, yielding a more reliable determination. The final draw angles were 73.5° and 74.7° for a hanging wall and footwall, respectively. Engineering applications demonstrated that this method significantly enhanced the accuracy of surface subsidence zone-boundary delineation, offering a transferable methodology for determining the rock draw angle and ensuring safe mining in deep mines.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100777"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145792212","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A unified thermo–hydro–mechanical load-transfer framework for energy piles: Quantifying interfacial softening","authors":"Tuan A. Pham ,&nbsp;Sadegh Nadimi ,&nbsp;Melis Sutman","doi":"10.1016/j.gete.2026.100810","DOIUrl":"10.1016/j.gete.2026.100810","url":null,"abstract":"<div><div>Energy piles, which serve concurrently as structural foundations and ground source heat exchangers, exhibit complex, coupled thermo-hydro-mechanical (THM) load-transfer responses that are often poorly predicted by conventional models. Current methodologies predominantly simplify the interaction, focusing primarily on temperature-induced pile expansion while overlooking crucial changes in the surrounding soil properties and interface behaviour. This paper presents a novel, unified load-transfer approach designed to accurately capture the nonlinear, multi-factor performance of energy piles embedded in multi-layered soils. The model's uniqueness lies in the simultaneous incorporation of advanced constitutive relationships that account for the temperature dependence of key geotechnical parameters, including thermal expansion/shrinkage of pile materials, radial thermal stress, total stress, particle contact area ratio, pore-water pressure, internal friction angle, effective cohesion, overconsolidation ratio, and suction stress. This framework explicitly integrates the effects of thermal softening of the soil skeleton and the generation of thermally induced excess pore-water pressure. The complex non-linear equilibrium is solved using an iterative Neutral Plane (NP) procedure to precisely determine the distribution of axial forces and skin friction. The predictive capability of the model is rigorously validated against three distinct full-scale field tests across diverse soil types: sandy silts, granular soils, and high-plasticity clays. Results show that the proposed method achieves high accuracy, with an average relative error ranging from 3% to 8.2% across all validation cases. Crucially, the analysis demonstrates that thermal effects significantly decrease or increase interface resistance depending on site characteristics, an observation that cannot be replicated when only pile expansion is considered. This work provides a robust, physics-based predictive tool essential for mitigating design risks associated with THM coupling, advancing the safe and efficient integration of geothermal energy systems into foundational engineering practice.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100810"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Discussion of “Assessment of an amended soil as a climate adaptive barrier: Element testing and physical modelling”","authors":"Vishnu Gopakumar,&nbsp;Bharat Venkata Tadikonda","doi":"10.1016/j.gete.2025.100784","DOIUrl":"10.1016/j.gete.2025.100784","url":null,"abstract":"<div><div>This discussion examines methodological and interpretative aspects of “Assessment of an amended soil as a climate adaptive barrier: element testing and physical modelling” by Rana et al., emphasizing critical insights for enhancing barrier reliability. Key concerns include the potential for measurement errors arising from delayed hydraulic response and equilibration protocols associated with tensiometer and ceramic sensor techniques. These issues cause significant disparities in soil water characteristic curve (SWCC) and hydraulic conductivity results. The discussion highlights that breakthrough mechanisms in fine-textured, water treatment residual (WTR) amended soils are best characterized by suction equilibrium rather than hydraulic conductivity convergence, aligning with recent research on capillary barrier systems. Environmental and long-term durability factors are discussed, including the implications of organic matter degradation, vegetation compatibility, and atmospheric drying cycle effects. The verification of sensor response times and long-term assessment are recommended to improve the robustness and utility of WTR-based climate adaptive barriers.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100784"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145884998","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cracking patterns, self-healing and properties of sand-bentonite liner under environmental stresses: A CT scanning and laboratory testing approach","authors":"Mina Fattahi,&nbsp;Reza Imam","doi":"10.1016/j.gete.2026.100786","DOIUrl":"10.1016/j.gete.2026.100786","url":null,"abstract":"<div><div>Compacted Impervious Liners (CILs) play a critical role in landfills by preventing environmental pollution. Where local soils do not meet stringent design criteria, soil amendment with bentonite is widely adopted to enhance properties of CILs. This study focuses on examining the behavior of a typical sand-bentonite mixture used as CIL and investigating the cracking patterns, self-healing properties in terms of hydraulic conductivity and uniaxial strength under wet-dry and freeze-thaw cycles, and effects of bentonite type and percentage on these properties. CT scanning and image processing results showed that in higher plasticity mixtures containing more sodium bentonite, cracks formed during wet-dry cycles tend to be larger and surficial; however, following freeze-thaw cycles, they are thinner, shorter and distributed uniformly over the sample depth. In the lower plasticity calcium bentonite mixtures, the cracking patterns during the two types of environmental stresses are reversed. Moreover, three patterns of changes in hydraulic conductivity and self healing during wet-dry cycles depending on the bentonite type of the mixture are also identified. Possible explanations for the cracking and self-healing observations are also provided. Effects of bentonite type and mixture plasticity on the various mixture properties including strength, stiffness, post-peak softening rate, failure mechanism, hydraulic conductivity, compaction properties, etc. are also examined. It was noticed that for the low PI mixture, wet-dry cycles finally lead to either increase or decrease in hydraulic conductivity depending on the mixture density.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100786"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927106","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of pore pressure-dependent friction laws on supershear earthquakes","authors":"Sandro Andrés ,&nbsp;David Santillán ,&nbsp;Ruben Juanes ,&nbsp;Luis Cueto-Felgueroso","doi":"10.1016/j.gete.2026.100787","DOIUrl":"10.1016/j.gete.2026.100787","url":null,"abstract":"<div><div>Supershear earthquakes are a particular class of seismic events in which the rupture velocity exceeds the shear wave velocity. These high-speed ruptures challenge conventional fault mechanics and have significant implications for the assessment of seismic hazards. This work investigates the relationship between pore pressure-dependent friction laws and the propagation of seismic ruptures, particularly the transition to supershear speeds. We present a numerical approach that couples fluid flow, rock deformation, and frictional contact, using stress-rate-dependent rate-and-state friction laws to simulate fault reactivation and rupture propagation. Our simulations demonstrate that the dependence of frictional properties on the effective normal stress rate can partially explain the occurrence of supershear ruptures, leading to a transition from sub-Rayleigh to supershear propagation patterns, as opposed to classical rate-and-state laws. We perform a parametric sweep, varying confining stresses, tectonic ratio, and fluid compressibility, and perform a dimensionless analysis to quantify the impact of hydromechanical parameters on supershear ruptures. Our analysis reveals that the stress drop during rupture is a key parameter in distinguishing between sub-Rayleigh and supershear rupture regimes. This study contributes to understanding the mechanisms that control fault friction behavior and its impact on seismic risk in underground reservoirs, which is crucial for the safe implementation of technologies such as green hydrogen storage and geothermal energy.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100787"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145927105","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geotechnical performance index to validate landfill cover efficiency: Cleaner production and circular economy in the Brazilian semi-arid region","authors":"Felipe Firmino Diniz ,&nbsp;Jordan Carneiro Martins de Souza ,&nbsp;Pabllo da Silva Araujo ,&nbsp;Tuilly de Fátima Furtado Guerra ,&nbsp;Rejane Nascentes ,&nbsp;Luiz Moreira Coelho Junior ,&nbsp;Veruschka Escarião Dessoles Monteiro ,&nbsp;Márcio Camargo de Melo","doi":"10.1016/j.gete.2026.100795","DOIUrl":"10.1016/j.gete.2026.100795","url":null,"abstract":"<div><div>The efficiency of landfill cover layers in gas retention is vital to mitigate environmental impacts, reduce biogas modeling uncertainties, and promote resource circularity and low-carbon transitions. This study applies the Geotechnical Performance Index (GPI) to evaluate the spatial relationship between geotechnical properties and greenhouse gas (GHG) emissions in a landfill in northeastern Brazil. The data was obtained through laboratory testing of the soil from the site, in situ testing at 21 points in the cover layer and physical-mechanical characterization of the soil. The GPI included parameters such as moisture (w), degree of compaction (C), dry density (γ_d), void ratio (<em>e</em>), porosity (<em>n</em>) and degree of saturation (S). Interpolate the data using QGIS®, I'Moran to analyze the spatial correlation and Global Warming Potential (GWP) analyzes. The CH₄ concentrations, of the 21 points analyzed, 95 % registered average values of less than 4 % v/v. The main CO₂ hotspot had a flow of &gt; 300 g.m⁻².d⁻¹, while for CH₄ it was 39 g.m⁻².d⁻¹. The GPI was suitable for assessing the efficiency of the landfill cover layer, showing positive spatial correlations with CO₂ (Moran's I = 0.105) and CH₄ (Moran's I = 0.064) fluxes. Under conservative, moderate and optimistic carbon-pricing scenarios (CO_2-eq), annual revenue estimates amounted to USD 63,285, USD 189,855 and USD 632,850, respectively, which highlights the economic leverage of methane-oriented interventions. The contributions demonstrate that landfill cover performance arises from coupled geotechnical, environmental, and biogeochemical interactions; targeted interventions can therefore elicit integrated responses and strengthen decision-making for landfill management and climate change mitigation.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100795"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146078047","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A novel analytical approach for evaluating thermally active underground retaining walls","authors":"Aakash Gupta ,&nbsp;Fleur Loveridge ,&nbsp;Ida Shafagh ,&nbsp;Simon J. Rees","doi":"10.1016/j.gete.2026.100812","DOIUrl":"10.1016/j.gete.2026.100812","url":null,"abstract":"<div><div>Shallow geothermal energy is a promising renewable technology for sustainable indoor heating and cooling. One method to exploit this energy is through Energy Geostructures, where structural elements embedded in the ground are thermally activated via heat exchange pipes embedded within the structure. These structures function as a specialised form of ground heat exchanger, which can be integrated with ground source heat pump systems. Energy walls (EWs), a specific type of Energy Geostructure, are commonly used in basements, underground parking facilities, and metro stations. Despite their potential, there is currently no simple and reliable analytical method for the thermal analysis of EWs. Instead, their design relies on computationally expensive numerical simulations or oversimplified 'rules of thumb', both of which may lead to inefficiencies in cost and performance. This study presents a novel analytical approach based on the Infinite Plane Source (IPS) model and evaluates its accuracy by comparing it with two-dimensional numerical model data. The results demonstrate that the proposed method provides highly accurate estimates of temperatures at the back of the wall, making it a valuable foundation for future analytical design methodologies. The findings are applicable to EWs having an excavation on one side and ground on the other, as well as fully buried EWs with soil on both sides. This research offers a significant step toward the development of a practical, cost-effective analytical framework for the design and optimisation of EWs, promoting the broader adoption of shallow geothermal energy systems.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100812"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147385346","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}