Pub Date : 2026-03-01Epub Date: 2025-12-20DOI: 10.1016/j.gete.2025.100782
Boran Huang , Jin Zhang , Qi-Zhi Zhu , Lunyang Zhao , Sili Liu
A temperature-dependent micromechanical creep–damage constitutive model is proposed within the framework of irreversible thermodynamics and homogenization theory to investigate the long-term thermo-mechanical behavior of quasi-brittle rocks. The model explicitly couples frictional sliding and microcrack propagation as the dominant modes of energy dissipation, where the friction coefficient, critical damage resistance, and damage threshold are expressed as temperature-dependent functions. Subcritical crack growth is incorporated to capture time-dependent damage accumulation and strain development. Model validation is conducted against triaxial thermo-creep experiments on gneissic granite, deep coals, and Beishan granite. The simulations reproduce the complete creep evolution – primary, secondary (steady-state), and tertiary (accelerated) stages – with relatively few parameters. The results clarify the role of creep rate—controlling factors, reveal the mechanisms of damage evolution and strain-rate acceleration under elevated temperatures, and demonstrate the promoting effect of thermal loading on energy dissipation. This unified framework not only advances the understanding of rock creep under coupled thermal–mechanical fields but also provides a theoretical basis for assessing the long-term thermal stability and reliability of deep underground engineering structures.
{"title":"Micromechanical modeling of long-term creep behavior of quasi-brittle rocks considering thermo-mechanical coupling effects","authors":"Boran Huang , Jin Zhang , Qi-Zhi Zhu , Lunyang Zhao , Sili Liu","doi":"10.1016/j.gete.2025.100782","DOIUrl":"10.1016/j.gete.2025.100782","url":null,"abstract":"<div><div>A temperature-dependent micromechanical creep–damage constitutive model is proposed within the framework of irreversible thermodynamics and homogenization theory to investigate the long-term thermo-mechanical behavior of quasi-brittle rocks. The model explicitly couples frictional sliding and microcrack propagation as the dominant modes of energy dissipation, where the friction coefficient, critical damage resistance, and damage threshold are expressed as temperature-dependent functions. Subcritical crack growth is incorporated to capture time-dependent damage accumulation and strain development. Model validation is conducted against triaxial thermo-creep experiments on gneissic granite, deep coals, and Beishan granite. The simulations reproduce the complete creep evolution – primary, secondary (steady-state), and tertiary (accelerated) stages – with relatively few parameters. The results clarify the role of creep rate—controlling factors, reveal the mechanisms of damage evolution and strain-rate acceleration under elevated temperatures, and demonstrate the promoting effect of thermal loading on energy dissipation. This unified framework not only advances the understanding of rock creep under coupled thermal–mechanical fields but also provides a theoretical basis for assessing the long-term thermal stability and reliability of deep underground engineering structures.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100782"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145841755","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}
Pub Date : 2026-03-01Epub Date: 2026-01-14DOI: 10.1016/j.gete.2026.100791
Marcelo Menezes Farias , Ivens da Costa Menezes Lima , Francisco Marcondes , Kamy Sepehrnoori
This work presents an unstructured grid-based formulation for compositional reservoir simulation coupled with elastic, elastoplastic, and viscoplastic geomechanical models. Implemented in the UTCOMPRS simulator using the Element-based Finite Volume Method (EbFVM), the proposed approach explicitly solves both flow and mechanical equations on unstructured grids. It supports nonlinear models, such as Mohr-Coulomb, Drucker-Prager, and a Perzyna-based viscoplastic criterion to represent material yield. Five case studies are conducted to verify the geomechanical implementation: Prandtl’s benchmark validates the plastic and viscoplastic models; primary production matched results from a commercial simulator; WAG injection and CO2 storage cases demonstrated the influence of the geomechanical model on production forecast, reservoir pressure, and rock deformation; and a Pre-Salt reservoir proxy tested computational efficiency, and numerical accuracy of the EbFVM across multiple grid refinements. Results show that the EbFVM captures nonlinear deformation while delivering solutions comparable to fine meshes using significantly coarser grids. The proposed formulation provides a robust and versatile tool for simulating complex reservoir-geomechanical problems.
{"title":"A unified Element-based Finite Volume Method for linear and nonlinear geomechanics and compositional reservoir simulation","authors":"Marcelo Menezes Farias , Ivens da Costa Menezes Lima , Francisco Marcondes , Kamy Sepehrnoori","doi":"10.1016/j.gete.2026.100791","DOIUrl":"10.1016/j.gete.2026.100791","url":null,"abstract":"<div><div>This work presents an unstructured grid-based formulation for compositional reservoir simulation coupled with elastic, elastoplastic, and viscoplastic geomechanical models. Implemented in the UTCOMPRS simulator using the Element-based Finite Volume Method (EbFVM), the proposed approach explicitly solves both flow and mechanical equations on unstructured grids. It supports nonlinear models, such as Mohr-Coulomb, Drucker-Prager, and a Perzyna-based viscoplastic criterion to represent material yield. Five case studies are conducted to verify the geomechanical implementation: Prandtl’s benchmark validates the plastic and viscoplastic models; primary production matched results from a commercial simulator; WAG injection and CO<sub>2</sub> storage cases demonstrated the influence of the geomechanical model on production forecast, reservoir pressure, and rock deformation; and a Pre-Salt reservoir proxy tested computational efficiency, and numerical accuracy of the EbFVM across multiple grid refinements. Results show that the EbFVM captures nonlinear deformation while delivering solutions comparable to fine meshes using significantly coarser grids. The proposed formulation provides a robust and versatile tool for simulating complex reservoir-geomechanical problems.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100791"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145978212","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}
Pub Date : 2026-03-01Epub Date: 2026-01-29DOI: 10.1016/j.gete.2026.100796
Stephen Pansino, Manuel A. Florez, Rafael Torres
Hydraulic fractures propagate in a form that depends on the forces acting on it, including the elastic forces of the rock, the viscous forces of the liquid, and the driving pressure gradient. Rock layering also needs to be accounted for, in which the rock properties can cause sharp changes in these forces. These factors influence the resulting surface area of a fracture, and therefore in the case of EGS, the ultimate productivity of a plant. The rising importance of EGS, and associated costs of drilling, bring a need for high quality models of fracture propagation, in order to assess plant productivity beforehand. We numerically simulate fracture propagation for a field site in the Llanos basin in Colombia, which has a monzogranite basement rock and overlying layers of sandstone and mudstone. We vary the fracture dip between models and keep the other parameters (material properties, injection rate, etc.) constant. Horizontally dipping fractures propagate radially and maintain a circular, penny-shape. Fractures with greater dips become vertically elongated due buoyancy forces, driving the propagation upwards. Fractures that propagate into overlying (softer) rock layers respond by reducing in horizontal breadth. We then assess the heat conduction into the fractures using 3D finite element modeling. Steeply-dipping fractures have larger surface areas (favorable for heat capture), but also propagate upwards into cooler rock. Horizontal fractures have smaller surface areas but remain at depth, in contact with hotter rock. There is a trade-off between these competing factors, so that fractures with dips of 30° maximize the heat capture. For the extensional tectonic environment of this site, we argue that a vertical fracture is likeliest to form. Therefore, in order for an EGS plant to be sufficiently productive, we recommend drilling an injection well that is deep enough to account for the upwards propagation of such a fracture, around 4 km depth.
{"title":"Modeling fracture growth for EGS in foreland sedimentary basins","authors":"Stephen Pansino, Manuel A. Florez, Rafael Torres","doi":"10.1016/j.gete.2026.100796","DOIUrl":"10.1016/j.gete.2026.100796","url":null,"abstract":"<div><div>Hydraulic fractures propagate in a form that depends on the forces acting on it, including the elastic forces of the rock, the viscous forces of the liquid, and the driving pressure gradient. Rock layering also needs to be accounted for, in which the rock properties can cause sharp changes in these forces. These factors influence the resulting surface area of a fracture, and therefore in the case of EGS, the ultimate productivity of a plant. The rising importance of EGS, and associated costs of drilling, bring a need for high quality models of fracture propagation, in order to assess plant productivity beforehand. We numerically simulate fracture propagation for a field site in the Llanos basin in Colombia, which has a monzogranite basement rock and overlying layers of sandstone and mudstone. We vary the fracture dip between models and keep the other parameters (material properties, injection rate, etc.) constant. Horizontally dipping fractures propagate radially and maintain a circular, penny-shape. Fractures with greater dips become vertically elongated due buoyancy forces, driving the propagation upwards. Fractures that propagate into overlying (softer) rock layers respond by reducing in horizontal breadth. We then assess the heat conduction into the fractures using 3D finite element modeling. Steeply-dipping fractures have larger surface areas (favorable for heat capture), but also propagate upwards into cooler rock. Horizontal fractures have smaller surface areas but remain at depth, in contact with hotter rock. There is a trade-off between these competing factors, so that fractures with dips of 30° maximize the heat capture. For the extensional tectonic environment of this site, we argue that a vertical fracture is likeliest to form. Therefore, in order for an EGS plant to be sufficiently productive, we recommend drilling an injection well that is deep enough to account for the upwards propagation of such a fracture, around 4 km depth.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"45 ","pages":"Article 100796"},"PeriodicalIF":3.7,"publicationDate":"2026-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146173571","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}
Pub Date : 2026-03-01Epub Date: 2025-12-11DOI: 10.1016/j.gete.2025.100777
Jiahui Tian , Ruiyang Bi , Jian Zhou , Zupu Xuan , Kun Du
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.
{"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 , Ruiyang Bi , Jian Zhou , Zupu Xuan , 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}
Pub Date : 2026-03-01Epub Date: 2026-02-26DOI: 10.1016/j.gete.2026.100810
Tuan A. Pham , Sadegh Nadimi , Melis Sutman
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.
{"title":"A unified thermo–hydro–mechanical load-transfer framework for energy piles: Quantifying interfacial softening","authors":"Tuan A. Pham , Sadegh Nadimi , 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}
Pub Date : 2026-03-01Epub Date: 2025-12-25DOI: 10.1016/j.gete.2025.100784
Vishnu Gopakumar, Bharat Venkata Tadikonda
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.
{"title":"Discussion of “Assessment of an amended soil as a climate adaptive barrier: Element testing and physical modelling”","authors":"Vishnu Gopakumar, 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}
Pub Date : 2026-03-01Epub Date: 2026-01-03DOI: 10.1016/j.gete.2026.100786
Mina Fattahi, Reza Imam
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.
{"title":"Cracking patterns, self-healing and properties of sand-bentonite liner under environmental stresses: A CT scanning and laboratory testing approach","authors":"Mina Fattahi, 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}
Pub Date : 2026-03-01Epub Date: 2026-01-05DOI: 10.1016/j.gete.2026.100787
Sandro Andrés , David Santillán , Ruben Juanes , Luis Cueto-Felgueroso
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.
{"title":"Effects of pore pressure-dependent friction laws on supershear earthquakes","authors":"Sandro Andrés , David Santillán , Ruben Juanes , 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}
Pub Date : 2026-03-01Epub Date: 2026-01-25DOI: 10.1016/j.gete.2026.100795
Felipe Firmino Diniz , Jordan Carneiro Martins de Souza , Pabllo da Silva Araujo , Tuilly de Fátima Furtado Guerra , Rejane Nascentes , Luiz Moreira Coelho Junior , Veruschka Escarião Dessoles Monteiro , Márcio Camargo de Melo
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 (γd), void ratio (e), porosity (n) 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 > 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 (CO2-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.
垃圾填埋场覆盖层的气体保留效率对于减轻环境影响、减少沼气模型的不确定性、促进资源循环和低碳转型至关重要。本研究应用岩土性能指数（GPI）对巴西东北部某垃圾填埋场岩土性能与温室气体（GHG）排放的空间关系进行了评价。这些数据是通过对现场土壤的实验室测试、覆盖层21个点的现场测试和土壤的物理力学表征获得的。GPI包括含水率(w)、压实度(C)、干密度（γd）、孔隙率(e)、孔隙率(n)和饱和度(S)等参数。使用QGIS®、I’moran对数据进行插值，分析空间相关性和全球变暖潜势（GWP）分析。分析的21个点中，95 %的CH4浓度平均值小于4 % v/v。主要的CO2热点流量为>； 300 g.m−2。而CH4为39 g.m−2.d−1。GPI与CO2 （Moran’s I = 0.105）和CH4 （Moran’s I = 0.064）通量呈空间正相关，适于评价填埋场覆盖层的效率。在保守、适度和乐观的碳定价情景（二氧化碳当量）下，年收入估计分别为63,285美元、189,855美元和632,850美元，这凸显了以甲烷为导向的干预措施的经济杠杆作用。研究表明，垃圾填埋场覆盖性能是由岩土、环境和生物地球化学相互作用引起的；因此，有针对性的干预措施可以引发综合反应，并加强垃圾填埋场管理和减缓气候变化的决策。
{"title":"Geotechnical performance index to validate landfill cover efficiency: Cleaner production and circular economy in the Brazilian semi-arid region","authors":"Felipe Firmino Diniz , Jordan Carneiro Martins de Souza , Pabllo da Silva Araujo , Tuilly de Fátima Furtado Guerra , Rejane Nascentes , Luiz Moreira Coelho Junior , Veruschka Escarião Dessoles Monteiro , 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<sub>d</sub>), 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 CH<sub>4</sub> concentrations, of the 21 points analyzed, 95 % registered average values of less than 4 % v/v. The main CO<sub>2</sub> hotspot had a flow of > 300 g.m<sup>−2</sup>.d<sup>−1</sup>, while for CH<sub>4</sub> it was 39 g.m<sup>−2</sup>.d<sup>−1</sup>. The GPI was suitable for assessing the efficiency of the landfill cover layer, showing positive spatial correlations with CO<sub>2</sub> (Moran's I = 0.105) and CH<sub>4</sub> (Moran's I = 0.064) fluxes. Under conservative, moderate and optimistic carbon-pricing scenarios (CO<sub>2-eq</sub>), 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}
Pub Date : 2026-03-01Epub Date: 2026-02-26DOI: 10.1016/j.gete.2026.100812
Aakash Gupta , Fleur Loveridge , Ida Shafagh , Simon J. Rees
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.
{"title":"A novel analytical approach for evaluating thermally active underground retaining walls","authors":"Aakash Gupta , Fleur Loveridge , Ida Shafagh , 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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号