Pub Date : 2025-09-14DOI: 10.1016/j.gete.2025.100741
Antash K. Sinha , Shrikrishna N. Joshi
Laser-based rock processing presents a transformative approach for mining, drilling, tunnelling, and geothermal applications by addressing key limitations of conventional mechanical methods, including excessive tool wear and operational inefficiencies. Despite its promise, challenges such as anisotropic rock behaviour, power transmission, formation damage, and instability in subsurface conditions require further investigation. This study examines the effectiveness of continual laser-based rock processing in inducing controlled damage and crack propagation in limestone rock. Distinct stages of rock failure – ranging from pore initiation to fragmentation and segmentation – were identified, revealing a progressive transition from microstructural alteration to macroscopic fracturing. A customized image analysis framework was employed to asses subsurface crack patterns, qualitatively and quantitatively with high fidelity, offering a robust tool for damage quantification. The results underscore the potential of controlled continual laser pulsing as a reliable method for targeted rock disintegration and highlight the role of image-based evaluation in advancing the mechanistic understanding of laser-rock interaction. These findings are expected to contribute positively for the development of next-generation rock-breaking and excavation technologies.
{"title":"Investigations into crack evolution during controlled continual laser-based rock processing","authors":"Antash K. Sinha , Shrikrishna N. Joshi","doi":"10.1016/j.gete.2025.100741","DOIUrl":"10.1016/j.gete.2025.100741","url":null,"abstract":"<div><div>Laser-based rock processing presents a transformative approach for mining, drilling, tunnelling, and geothermal applications by addressing key limitations of conventional mechanical methods, including excessive tool wear and operational inefficiencies. Despite its promise, challenges such as anisotropic rock behaviour, power transmission, formation damage, and instability in subsurface conditions require further investigation. This study examines the effectiveness of continual laser-based rock processing in inducing controlled damage and crack propagation in limestone rock. Distinct stages of rock failure – ranging from pore initiation to fragmentation and segmentation – were identified, revealing a progressive transition from microstructural alteration to macroscopic fracturing. A customized image analysis framework was employed to asses subsurface crack patterns, qualitatively and quantitatively with high fidelity, offering a robust tool for damage quantification. The results underscore the potential of controlled continual laser pulsing as a reliable method for targeted rock disintegration and highlight the role of image-based evaluation in advancing the mechanistic understanding of laser-rock interaction. These findings are expected to contribute positively for the development of next-generation rock-breaking and excavation technologies.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"44 ","pages":"Article 100741"},"PeriodicalIF":3.7,"publicationDate":"2025-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145158604","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 : 2025-09-13DOI: 10.1016/j.gete.2025.100740
Wenpei Ma , Henry McKlin , Russell Chan , Caitlin Kim , Teagan DePoint-Spang , Ingrid Tomac
This paper investigates the use of environmentally friendly remediation materials and techniques for rain-induced post-wildfire soil erosion on burned slopes. During wildfires, vegetation and organic matter combust and release hydrophobic chemicals on soil grains. Hydrophobicity reduces the water infiltration rate, prolongs the wetting process, increases erosion, and causes severe debris flows over watersheds. This comparative study presents the most effective approaches for mitigating hydrophobicity effects through environmentally friendly biopolymers and surfactants. Experimental techniques evaluate the dynamics of water drop penetration into treated and untreated soil, downhill water drop mobility, and erosion. The waterdrop contact angle measurements indicate that biopolymer Xanthan Gum (XG) slightly reduces hydrophobicity, whereas surfactant Sodium Cocoyl Isethionate (SCI) reduces it by a factor of a thousand. In addition, SCI can decrease slope erosion at low-inclined and moderate-inclined slopes. Sands' infiltration rates (IR) are very fast due to high permeability in normal conditions; however, surface hydrophobicity significantly reduces IR. Results from artificially treated extremely water-repellent samples of mixed sand show a six orders of magnitude decrease in IR. Then, after treatments XG and SCI modifiers, the IR increased by an order of magnitude after the XG treatments, and by four orders of magnitude under SCI treatment. Although XG is wettable and attractive to water, the crust and webs it forms between sand particles prevent effective water infiltration. Mild slopes exhibit similar IR rates as horizontal surfaces for all the cases; however, steeper slopes reduce IR for treated hydrophobic soils because they allow for downhill motion of water that is faster relative to the infiltration speed.
{"title":"Post-wildfire soil hydrophobicity and slope erosion remediation by applying environmentally friendly modifiers","authors":"Wenpei Ma , Henry McKlin , Russell Chan , Caitlin Kim , Teagan DePoint-Spang , Ingrid Tomac","doi":"10.1016/j.gete.2025.100740","DOIUrl":"10.1016/j.gete.2025.100740","url":null,"abstract":"<div><div>This paper investigates the use of environmentally friendly remediation materials and techniques for rain-induced post-wildfire soil erosion on burned slopes. During wildfires, vegetation and organic matter combust and release hydrophobic chemicals on soil grains. Hydrophobicity reduces the water infiltration rate, prolongs the wetting process, increases erosion, and causes severe debris flows over watersheds. This comparative study presents the most effective approaches for mitigating hydrophobicity effects through environmentally friendly biopolymers and surfactants. Experimental techniques evaluate the dynamics of water drop penetration into treated and untreated soil, downhill water drop mobility, and erosion. The waterdrop contact angle measurements indicate that biopolymer Xanthan Gum (XG) slightly reduces hydrophobicity, whereas surfactant Sodium Cocoyl Isethionate (SCI) reduces it by a factor of a thousand. In addition, SCI can decrease slope erosion at low-inclined and moderate-inclined slopes. Sands' infiltration rates (IR) are very fast due to high permeability in normal conditions; however, surface hydrophobicity significantly reduces IR. Results from artificially treated extremely water-repellent samples of mixed sand show a six orders of magnitude decrease in IR. Then, after treatments XG and SCI modifiers, the IR increased by an order of magnitude after the XG treatments, and by four orders of magnitude under SCI treatment. Although XG is wettable and attractive to water, the crust and webs it forms between sand particles prevent effective water infiltration. Mild slopes exhibit similar IR rates as horizontal surfaces for all the cases; however, steeper slopes reduce IR for treated hydrophobic soils because they allow for downhill motion of water that is faster relative to the infiltration speed.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"44 ","pages":"Article 100740"},"PeriodicalIF":3.7,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106906","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 : 2025-09-12DOI: 10.1016/j.gete.2025.100737
Moones Alamooti, Shane Namie
Sedimentary basin geothermal systems face critical characterization challenges from complex reservoir heterogeneity that traditional assessment methods inadequately address. This study develops an integrated petrophysical-structural framework for the Deadwood Formation in North Dakota's Williston Basin using advanced rock physics modeling and statistical fracture analysis. We employed Differential Effective Medium theory for bimodal pore structures (macropores 10–100 micrometers, micropores <1 micrometer), Kuster-Toksöz analysis for fracture-induced anisotropy with aspect ratios 0.001–1.0, and Gassmann fluid substitution with empirically constrained parameters. Formation Micro-Imager logs at 5 millimeter resolution enabled statistical characterization of 847 fractures across 450 feet, with uncertainty quantification through Monte Carlo simulation. Results demonstrate exceptional geothermal potential with a validated gradient of 34.6°C/km, significantly exceeding typical sedimentary basin values of 25–30°C/km, achieving 160–162°C at economically viable depths of 3.0–3.1 kilometers. Fracture networks follow log-normal distributions with volumetric intensities of 0.07–2.82 fractures/ft3 and a coefficient of variation of 79 %, requiring stochastic modeling approaches. Rock physics modeling successfully discriminates reservoir zones with correlation coefficients exceeding 0.87, identifying Members B and A as optimal targets. Economic analysis demonstrates commercial viability with levelized electricity costs of 8.7 cents per kilowatt-hour (confidence interval: 6.1–12.4), competitive with renewable alternatives. The superior depth-to-temperature ratio of 18.9–19.4 m per degree Celsius provides 25–45 % cost advantages over typical sedimentary prospects. Parameter bounds were constrained by core and log data (φ = 0.08 – 0.18; Ks = 37 – 43 GPa; K-f = 0.02 – 2.3 GPa across steam-brine scenarios), with dry-frame moduli from DEM directly feeding Gassman substitution. This integrated framework advances sedimentary geothermal assessment while establishing replicable protocols for global application, contributing to sustainable energy transition goals.
{"title":"Rock physics and fracture characterization of the Deadwood Formation, Williston Basin: Insights into geothermal resource development","authors":"Moones Alamooti, Shane Namie","doi":"10.1016/j.gete.2025.100737","DOIUrl":"10.1016/j.gete.2025.100737","url":null,"abstract":"<div><div>Sedimentary basin geothermal systems face critical characterization challenges from complex reservoir heterogeneity that traditional assessment methods inadequately address. This study develops an integrated petrophysical-structural framework for the Deadwood Formation in North Dakota's Williston Basin using advanced rock physics modeling and statistical fracture analysis. We employed Differential Effective Medium theory for bimodal pore structures (macropores 10–100 micrometers, micropores <1 micrometer), Kuster-Toksöz analysis for fracture-induced anisotropy with aspect ratios 0.001–1.0, and Gassmann fluid substitution with empirically constrained parameters. Formation Micro-Imager logs at 5 millimeter resolution enabled statistical characterization of 847 fractures across 450 feet, with uncertainty quantification through Monte Carlo simulation. Results demonstrate exceptional geothermal potential with a validated gradient of 34.6°C/km, significantly exceeding typical sedimentary basin values of 25–30°C/km, achieving 160–162°C at economically viable depths of 3.0–3.1 kilometers. Fracture networks follow log-normal distributions with volumetric intensities of 0.07–2.82 fractures/ft<sup>3</sup> and a coefficient of variation of 79 %, requiring stochastic modeling approaches. Rock physics modeling successfully discriminates reservoir zones with correlation coefficients exceeding 0.87, identifying Members B and A as optimal targets. Economic analysis demonstrates commercial viability with levelized electricity costs of 8.7 cents per kilowatt-hour (confidence interval: 6.1–12.4), competitive with renewable alternatives. The superior depth-to-temperature ratio of 18.9–19.4 m per degree Celsius provides 25–45 % cost advantages over typical sedimentary prospects. Parameter bounds were constrained by core and log data (φ = 0.08 – 0.18; K<sub>s</sub> = 37 – 43 GPa; K-f = 0.02 – 2.3 GPa across steam-brine scenarios), with dry-frame moduli from DEM directly feeding Gassman substitution. This integrated framework advances sedimentary geothermal assessment while establishing replicable protocols for global application, contributing to sustainable energy transition goals.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"44 ","pages":"Article 100737"},"PeriodicalIF":3.7,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106797","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 : 2025-09-08DOI: 10.1016/j.gete.2025.100738
Jianping Zuo , Bo Lei , Genshui Wu , Haiyan Liu , Massimo Coli
Research on the failure behavior of Longmaxi shale is vital for shale reservoir reconstruction. Shale inherently contains some initial micro-cracks, which significantly affect its strength and failure behavior. In this paper, a refined boundary multi-level parallel bonded grain-based model (multi-level PB-GBM) in Particle Flow Code (PFC2D) was developed, and the effect of inherent initial damage on shale strength and failure behavior was quantitatively investigated. The results showed that inherent initial damage significantly influences the failure pattern and mechanical properties of shale. The newly generated cracks of the initially damaged samples are significantly self-organized compared with those of the undamaged samples, indicating that the inherent initial damaged cracks induce the orientation and aggregation of micro-cracks. High initially damaged samples mainly demonstrate by splitting-shear coupled fracture as a result of the co-evolution of primary and secondary micro-cracks. Generally, rock strength gradually decreases as the initial damage increases. When the inherent initial damage within the sample is low, the rock strength is greatly influenced by confining pressure, whereas when the initial damage is high enough, the initial damage contributes more to the rock strength.
{"title":"Investigation on mechanical response and fracture behavior of initially damaged shale based on multi-level PB-GBM method","authors":"Jianping Zuo , Bo Lei , Genshui Wu , Haiyan Liu , Massimo Coli","doi":"10.1016/j.gete.2025.100738","DOIUrl":"10.1016/j.gete.2025.100738","url":null,"abstract":"<div><div>Research on the failure behavior of Longmaxi shale is vital for shale reservoir reconstruction. Shale inherently contains some initial micro-cracks, which significantly affect its strength and failure behavior. In this paper, a refined boundary multi-level parallel bonded grain-based model (multi-level PB-GBM) in Particle Flow Code (PFC2D) was developed, and the effect of inherent initial damage on shale strength and failure behavior was quantitatively investigated. The results showed that inherent initial damage significantly influences the failure pattern and mechanical properties of shale. The newly generated cracks of the initially damaged samples are significantly self-organized compared with those of the undamaged samples, indicating that the inherent initial damaged cracks induce the orientation and aggregation of micro-cracks. High initially damaged samples mainly demonstrate by splitting-shear coupled fracture as a result of the co-evolution of primary and secondary micro-cracks. Generally, rock strength gradually decreases as the initial damage increases. When the inherent initial damage within the sample is low, the rock strength is greatly influenced by confining pressure, whereas when the initial damage is high enough, the initial damage contributes more to the rock strength.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"44 ","pages":"Article 100738"},"PeriodicalIF":3.7,"publicationDate":"2025-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106909","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 : 2025-09-02DOI: 10.1016/j.gete.2025.100736
Jiacun Liu , Junjie Xiao , Ying Xu , Xing Li , Kaiwen Xia , Gang Han
Under the influence of high three-dimensional geostress, rocks transition into the ductile domain, undergoing continuous plastic hardening and volumetric contraction. Accurately describing the three-dimensional anisotropic deformation of rocks within ductile domain is of great significance for deep underground engineering. Therefore, a three-dimensional fractional elastoplastic constitutive within ductile domain is proposed in this study, including yield function and fractional flow rule. The ductile yield function is based on the modified Mohr-Coulomb criterion and generalized Matsuoka-Nakai deviatoric function. The deviatoric stress of yield surface is negatively correlated to hydrostatic pressure, but positively correlated to Lode angle. The yield surfaces in both meridian and deviatoric planes evolve with the plastic internal variable, accurately capturing the stress state during hardening. Two different fractional orders are used to control the plastic flow direction within meridian and deviatoric planes, represented by dilation angle and plastic deflection angle, respectively. These fractional orders are determined based on the relationship between plastic shear strain and volumetric strain, and they vary with the plastic internal variable, effectively capturing the plastic flow direction throughout hardening. The proposed model is validated using green sandstone data from hydrostatic compression and true-triaxial tests. The effect of fractional orders on the dilation angle and plastic deflection angle is discussed. Under the influence of fractional orders, both dilation angle and plastic deflection angle range from to . Besides, a comparison between the non-orthogonality and orthogonality flow rules is made. These results indicate that the fractional flow rule significantly improves the applicability and accuracy of constitutive model.
{"title":"A three-dimensional fractional elastoplastic constitutive model for rocks within ductile domain","authors":"Jiacun Liu , Junjie Xiao , Ying Xu , Xing Li , Kaiwen Xia , Gang Han","doi":"10.1016/j.gete.2025.100736","DOIUrl":"10.1016/j.gete.2025.100736","url":null,"abstract":"<div><div>Under the influence of high three-dimensional geostress, rocks transition into the ductile domain, undergoing continuous plastic hardening and volumetric contraction. Accurately describing the three-dimensional anisotropic deformation of rocks within ductile domain is of great significance for deep underground engineering. Therefore, a three-dimensional fractional elastoplastic constitutive within ductile domain is proposed in this study, including yield function and fractional flow rule. The ductile yield function is based on the modified Mohr-Coulomb criterion and generalized Matsuoka-Nakai deviatoric function. The deviatoric stress of yield surface is negatively correlated to hydrostatic pressure, but positively correlated to Lode angle. The yield surfaces in both meridian and deviatoric planes evolve with the plastic internal variable, accurately capturing the stress state during hardening. Two different fractional orders are used to control the plastic flow direction within meridian and deviatoric planes, represented by dilation angle and plastic deflection angle, respectively. These fractional orders are determined based on the relationship between plastic shear strain and volumetric strain, and they vary with the plastic internal variable, effectively capturing the plastic flow direction throughout hardening. The proposed model is validated using green sandstone data from hydrostatic compression and true-triaxial tests. The effect of fractional orders on the dilation angle and plastic deflection angle is discussed. Under the influence of fractional orders, both dilation angle and plastic deflection angle range from <span><math><msup><mrow><mn>0</mn></mrow><mo>∘</mo></msup></math></span> to <span><math><mrow><mo>−</mo><msup><mrow><mn>90</mn></mrow><mo>∘</mo></msup></mrow></math></span>. Besides, a comparison between the non-orthogonality and orthogonality flow rules is made. These results indicate that the fractional flow rule significantly improves the applicability and accuracy of constitutive model.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"44 ","pages":"Article 100736"},"PeriodicalIF":3.7,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145005361","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 : 2025-09-01DOI: 10.1016/j.gete.2025.100735
Jian Xu , Liangkun Ding , Zihan Li , Jiayuan Li
This study employed the microbially induced calcium carbonate precipitation (MICP) technique to investigate the mechanism of desert sand stabilization through a multiscale approach, ranging from macro to micro levels. A multi-objective optimization model was created to enhance surface strength, CaCO3 content, and solidified layer thickness using a comprehensive analysis of multiple factors. The solidification effect was validated with wind tunnel and water retention tests. Microstructural mechanisms were examined through XRD, SEM, and PCAS. Results indicate that the optimum parameters for MICP technology are the 1:2.12 mix ratio, the 1.895 mol/L cementation solution concentration, and 4 treatment cycles. There was also a clear correlation between the performance indexes after solidification. The parameters optimized by the response surface method were essentially the same as those obtained from the experiments, with a difference of less than 5 % between the repeated test results and the optimized results. Under conditions of high CSC (single treatment cycle) or low CSC (multiple treatment cycles), MICP-treated desert sands can achieve highly efficient sand fixation and long-lasting water retention. Microanalysis revealed that increasing CSC and Tc altered the mode of particle contact from point to surface, and a significant negative correlation was observed between pore parameters and surface strength. This proves that it improves the water retention and mechanical strength of desert sand.
{"title":"MICP-enhanced wind erosion resistance of desert sand: process parameter optimization and microstructural mechanism","authors":"Jian Xu , Liangkun Ding , Zihan Li , Jiayuan Li","doi":"10.1016/j.gete.2025.100735","DOIUrl":"10.1016/j.gete.2025.100735","url":null,"abstract":"<div><div>This study employed the microbially induced calcium carbonate precipitation (MICP) technique to investigate the mechanism of desert sand stabilization through a multiscale approach, ranging from macro to micro levels. A multi-objective optimization model was created to enhance surface strength, CaCO<sub>3</sub> content, and solidified layer thickness using a comprehensive analysis of multiple factors. The solidification effect was validated with wind tunnel and water retention tests. Microstructural mechanisms were examined through XRD, SEM, and PCAS. Results indicate that the optimum parameters for MICP technology are the 1:2.12 mix ratio, the 1.895 mol/L cementation solution concentration, and 4 treatment cycles. There was also a clear correlation between the performance indexes after solidification. The parameters optimized by the response surface method were essentially the same as those obtained from the experiments, with a difference of less than 5 % between the repeated test results and the optimized results. Under conditions of high <em>CSC</em> (single treatment cycle) or low <em>CSC</em> (multiple treatment cycles), MICP-treated desert sands can achieve highly efficient sand fixation and long-lasting water retention. Microanalysis revealed that increasing <em>CSC</em> and <em>T</em><sub><em>c</em></sub> altered the mode of particle contact from point to surface, and a significant negative correlation was observed between pore parameters and surface strength. This proves that it improves the water retention and mechanical strength of desert sand.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100735"},"PeriodicalIF":3.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144925645","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 : 2025-09-01DOI: 10.1016/j.gete.2025.100706
Philip J. Vardon , Anne-Catherine Dieudonné , John. S. McCartney , Jean-Michel Pereira , David Smeulders , Guillermo Narsilio
{"title":"Accelerating the Energy Transition with Energy Geotechnics: editorial","authors":"Philip J. Vardon , Anne-Catherine Dieudonné , John. S. McCartney , Jean-Michel Pereira , David Smeulders , Guillermo Narsilio","doi":"10.1016/j.gete.2025.100706","DOIUrl":"10.1016/j.gete.2025.100706","url":null,"abstract":"","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100706"},"PeriodicalIF":3.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145048917","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 : 2025-08-29DOI: 10.1016/j.gete.2025.100731
A. Gajo
The energy and entropy balance equations of porous media saturated by one or more non-miscible fluids have been investigated by many Authors leading to expressions which are based on different thermodynamic potentials and include various simplifying assumptions. Thus the various approaches often appear to be unrelated with respect to each other. In this work, two thermodynamic potentials recently proposed in the literature for porous media saturated by one or two non-miscible and compressible pore fluids are exploited for reconsidering different and perfectly equivalent expressions of the energy balance equations given in terms of internal energies, entropies and enthalpies, without simplifying assumptions. In particular, the entropy fluxes and the dissipation functions are presented for a simple case of irreversible response of the solid skeleton, involving neither irreversibility of the solid grain response, nor elastoplastic coupling nor frozen inelastic energy. Some comparisons with the formulations proposed in the literature are discussed.
{"title":"Energy and entropy balance laws for porous media saturated by one or two non-miscible pore fluids at different temperatures","authors":"A. Gajo","doi":"10.1016/j.gete.2025.100731","DOIUrl":"10.1016/j.gete.2025.100731","url":null,"abstract":"<div><div>The energy and entropy balance equations of porous media saturated by one or more non-miscible fluids have been investigated by many Authors leading to expressions which are based on different thermodynamic potentials and include various simplifying assumptions. Thus the various approaches often appear to be unrelated with respect to each other. In this work, two thermodynamic potentials recently proposed in the literature for porous media saturated by one or two non-miscible and compressible pore fluids are exploited for reconsidering different and perfectly equivalent expressions of the energy balance equations given in terms of internal energies, entropies and enthalpies, without simplifying assumptions. In particular, the entropy fluxes and the dissipation functions are presented for a simple case of irreversible response of the solid skeleton, involving neither irreversibility of the solid grain response, nor elastoplastic coupling nor frozen inelastic energy. Some comparisons with the formulations proposed in the literature are discussed.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"44 ","pages":"Article 100731"},"PeriodicalIF":3.7,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145333440","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 : 2025-08-24DOI: 10.1016/j.gete.2025.100734
Yan-jie Feng , Cheng-zhi Qi , Fa Zhao , Tao Li , An-sen Gao , Xiao-yu Ma
The deformation and failure of rock are affected by the strain rate. However, the effect of the strain rate on rock failure has not been well studied at the microscale level. This study focuses on this complexity by constructing a three-scale wing-shaped crack propagation model that accounts for the interactions between cracks. Based on this model, we determined the initiation and coalescence times of 3 scale levels cracks to reveal the effect of the strain rate on the propagation and failure patterns of multiscale cracks. In addition, we analyzed the critical strain rate (strain rate required for simultaneous coalescence of adjacent scale-level cracks) that leads to failure. The results show that both crack initiation and coalescence times decrease significantly with increasing strain rate and that an increase in initial crack length leads to earlier crack initiation. For the multiscale crack model, as the strain rate increases, large-scale cracks (1-st-scale level cracks) coalesce first, followed sequentially by medium- and small-scale cracks (2-nd and 3-d-scale level cracks). Furthermore, we observed that the critical strain rate initially increases and then decreases with increasing initial crack concentration. Moreover, both an increase in the initial crack length and size decrease factor (ratio of the length of a specific scale-level crack to the length of adjacent larger scale-level cracks) lead to a decrease in the critical strain rate, further confirming the influence of crack size on the failure properties of rock. A comparison with the existing theoretical model shows that the proposed theoretical model is reasonable.
{"title":"Influence of the strain rate on the deformation and failure of rocks with multiscale cracks","authors":"Yan-jie Feng , Cheng-zhi Qi , Fa Zhao , Tao Li , An-sen Gao , Xiao-yu Ma","doi":"10.1016/j.gete.2025.100734","DOIUrl":"10.1016/j.gete.2025.100734","url":null,"abstract":"<div><div>The deformation and failure of rock are affected by the strain rate. However, the effect of the strain rate on rock failure has not been well studied at the microscale level. This study focuses on this complexity by constructing a three-scale wing-shaped crack propagation model that accounts for the interactions between cracks. Based on this model, we determined the initiation and coalescence times of 3 scale levels cracks to reveal the effect of the strain rate on the propagation and failure patterns of multiscale cracks. In addition, we analyzed the critical strain rate (strain rate required for simultaneous coalescence of adjacent scale-level cracks) that leads to failure. The results show that both crack initiation and coalescence times decrease significantly with increasing strain rate and that an increase in initial crack length leads to earlier crack initiation. For the multiscale crack model, as the strain rate increases, large-scale cracks (1-st-scale level cracks) coalesce first, followed sequentially by medium- and small-scale cracks (2-nd and 3-d-scale level cracks). Furthermore, we observed that the critical strain rate initially increases and then decreases with increasing initial crack concentration. Moreover, both an increase in the initial crack length and size decrease factor (ratio of the length of a specific scale-level crack to the length of adjacent larger scale-level cracks) lead to a decrease in the critical strain rate, further confirming the influence of crack size on the failure properties of rock. A comparison with the existing theoretical model shows that the proposed theoretical model is reasonable.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100734"},"PeriodicalIF":3.7,"publicationDate":"2025-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144894788","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}
This paper presents a numerical comparison of the vertical pull-out capacity of square and circular anchors in purely cohesive soils (i.e. clays in undrained conditions). For simplicity, ultrathin, infinitely rigid anchors are considered and to isolate the effect of anchor shape, comparisons are made between anchors of equal area and embedment depth. Finite Element Limit Analyses (FELA) are used to compute upper and lower bound values of the break-out factor over the full range of embedment ratios, and the associated failure mechanisms are identified. The results show for the first time (to the best of the authors’ knowledge) that square anchors exhibit slightly higher efficiency at shallow embedment ratios due to their larger perimeter, while at greater depths, circular anchors become more efficient as a result of the different failure mechanisms involved. The study also investigates the influence of anchor inclination and shows that inclined anchors have a higher pull-out capacity in vented conditions due to elongated failure mechanisms. Under attached conditions, the deep failure mechanism is obtained in most cases with the corresponding constant break-out factor. In addition, the paper analyses the influence of anchor spacing in anchor groups, identifying optimal spacing to avoid capacity reduction due to interaction effects. For shallow depths, a spacing of about two times the anchor width is sufficient, while deeper installations require larger spacings due to the extended failure zone. Once the deep failure mechanism is reached, spacing requirements decrease again, less than two times the anchor width. Overall, the presented numerical simulations offer insights for the design of plate anchors in cohesive soils, contributing to the advancement of offshore foundation technologies.
{"title":"Numerical comparison between square and circular plate anchors in clay","authors":"Mohammadreza Jahanshahinowkandeh, Marina Miranda, Jorge Castro","doi":"10.1016/j.gete.2025.100733","DOIUrl":"10.1016/j.gete.2025.100733","url":null,"abstract":"<div><div>This paper presents a numerical comparison of the vertical pull-out capacity of square and circular anchors in purely cohesive soils (i.e. clays in undrained conditions). For simplicity, ultrathin, infinitely rigid anchors are considered and to isolate the effect of anchor shape, comparisons are made between anchors of equal area and embedment depth. Finite Element Limit Analyses (FELA) are used to compute upper and lower bound values of the break-out factor over the full range of embedment ratios, and the associated failure mechanisms are identified. The results show for the first time (to the best of the authors’ knowledge) that square anchors exhibit slightly higher efficiency at shallow embedment ratios due to their larger perimeter, while at greater depths, circular anchors become more efficient as a result of the different failure mechanisms involved. The study also investigates the influence of anchor inclination and shows that inclined anchors have a higher pull-out capacity in vented conditions due to elongated failure mechanisms. Under attached conditions, the deep failure mechanism is obtained in most cases with the corresponding constant break-out factor. In addition, the paper analyses the influence of anchor spacing in anchor groups, identifying optimal spacing to avoid capacity reduction due to interaction effects. For shallow depths, a spacing of about two times the anchor width is sufficient, while deeper installations require larger spacings due to the extended failure zone. Once the deep failure mechanism is reached, spacing requirements decrease again, less than two times the anchor width. Overall, the presented numerical simulations offer insights for the design of plate anchors in cohesive soils, contributing to the advancement of offshore foundation technologies.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100733"},"PeriodicalIF":3.7,"publicationDate":"2025-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144911968","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}
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