Geomechanics for Energy and the Environment最新文献

{"title":"Creep characteristics and damage mechanisms of rock in the plateau tunnel: Insights from acoustic emission and energy evolution","authors":"Yanzhe Li,&nbsp;Chuanxin Rong,&nbsp;Zhensen Wang,&nbsp;Yang Wang","doi":"10.1016/j.gete.2025.100720","DOIUrl":"10.1016/j.gete.2025.100720","url":null,"abstract":"<div><div>The in-situ stress in plateau tunnels is significantly high and exhibits a complex distribution. Consequently, the long-term creep behavior of deep surrounding rock poses a critical challenge to the stability and integrity of tunnel engineering in plateau mountainous areas. To address this issue, this study performs triaxial creep tests on gneissic granite samples obtained from plateau tunnels under various stress paths. Additionally, the mechanical analysis is enhanced by incorporating acoustic emission characteristics and energy evolution. Two stress paths—continuous loading and confining pressure unloading—were implemented. Key parameters, including AE count, cumulative energy, and energy competition ratio <em>R</em>, were analyzed. The results indicate that: (1) Under the confining pressure unloading path, the accelerated creep stage duration,which just occupied 1.33 % of total loading time, was significantly shorter than that under continuous loading, with a 12.3 % reduction in failure strength, suggesting lower confinement facilitates microcrack propagation and rapid instability; (2) AE parameters and energy release patterns effectively characterized creep stages: steady-state creep exhibited steady AE activity, while abrupt increased in N and ΣE mark accelerated creep, with shear-dominated failure of over 69.9 %; (3) The energy competition ratio <em>R</em> grew exponentially beyond the critical deviatoric stress, though localized energy aggregation still triggered shear failure. This study elucidates how stress paths govern energy distribution and damage evolution, providing theoretical insights for stability assessment and disaster prevention in plateau tunnel engineering.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100720"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144634529","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":"Research on the brittle characteristics of shale under long-term CO2-H2O-shale coupling effects","authors":"Zhengjie Liu ,&nbsp;Yongdong Jiang ,&nbsp;Shizhe Song ,&nbsp;Hongtao Zhang ,&nbsp;Fuxin Guo","doi":"10.1016/j.gete.2025.100696","DOIUrl":"10.1016/j.gete.2025.100696","url":null,"abstract":"<div><div>Hybrid fracturing focuses on optimizing the extraction of shale gas. In order to solve the issues of shale reservoir fracturing and CO₂ storage stability. Research was conducted to examine the mechanical properties of shale under long-term CO₂-H₂O-shale coupling effects. The results reveal that the SC-CO₂-H₂O-shale coupling effects increase shale porosity and pore size due to the dissolution of minerals. Concurrently, Shale cohesion and internal friction angle decrease. Following prolonged SC-CO₂-H₂O-shale coupling effects, there is a decline in shale strength and elastic modulus decline, alongside a decrease in axial strain (such as the growth of the compaction segment, but the shortening of the elastic and strain hardening segments). lateral strain increase, resulting in a higher Poisson's ratio. Additionally, the indices BI₁ rises by 47.44 %, whereas BI₂ drops by 66.85 %, improving the shale's drillability and cuttability. the indices BI₃, BI₄, BI₅, and BI₆ increase by 11.90 %, 45.10 %, 15.19 %, and 8.99 %, respectively, highlighting the shale's brittle characteristics. However, the indices BI₇, BI₈, and BI₉ decrease by 35.05 %, 38.20 %, and 46.67 %, indicating a reduction in the shale's fracturability. Confining pressure reduces lateral strain and increases axial strain, result in an increase in shale Poisson's ratio and strength. Following enhanced confining pressure, the indices BI₃ drops by 1.19–10.61 %, BI₄ decreases by 43.14–61.29 %, BI₅ falls by 1.27–14.29 %, and BI₆ declines by 1.12–8.42 %. Consequently, the failure characteristics transition from brittle to plastic. The SC-CO₂-H₂O-shale coupling effects facilitate the growth of fractures in unfractured areas. However, the elevated ground stress and reduced fracturability of the shale reservoirs restricts the growth of fractures in fractured zone, ensuring the stability of CO₂ storage.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100696"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144241042","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":"Centrifuge modelling of energy geostructures in soil: A review","authors":"Rui Zhao ,&nbsp;Cong Shao ,&nbsp;Jonathan Adam Knappett ,&nbsp;Anthony Kwan Leung ,&nbsp;Teng Liang ,&nbsp;Liangtong Zhan ,&nbsp;Yunmin Chen","doi":"10.1016/j.gete.2025.100719","DOIUrl":"10.1016/j.gete.2025.100719","url":null,"abstract":"<div><div>Energy geostructures integrate heat exchange pipes of ground source heat pump systems within traditional underground structures, serving the dual purpose of extracting geothermal energy and supporting above-ground structures. The interaction between geothermal structures and soil involves heat transfer, pore pressure evolution and soil skeleton deformation, exhibiting a coupled thermo-hydro-mechanical response. Although detailed numerical and analytical models have been developed to analyze the thermo-hydro-mechanical behaviour of energy geostructures in soil, significant challenges remain in validating this coupled response. Centrifuge modelling provides prototype confining stresses in reduced-scale models, providing an alternative to field measurements with more controllable conditions and at lower cost. This paper reviews the current state of the art of centrifuge modelling of energy geostructure–soil interaction, with a particular focus on (i) scaling laws; (ii) evaluations of existing heating and cooling systems; (iii) soil modelling, including material selection and model preparation; and (iv) scale modelling of energy geostructural elements. Each section emphasizes the challenges of centrifuge modelling and presents identified solutions to these challenges. Finally, the prospect for future studies is discussed, highlighting the potential to enhance understanding of the underlying mechanisms controlling thermo-hydro-mechanical behaviour of geothermal structures in soil.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100719"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703677","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":"Thermal influence zone of energy tunnels in sandy soils under the hydrostatic condition","authors":"Alaaeldin Magdy ,&nbsp;Alice Di Donna ,&nbsp;Hussein Mroueh","doi":"10.1016/j.gete.2025.100716","DOIUrl":"10.1016/j.gete.2025.100716","url":null,"abstract":"<div><div>Energy geostructures are more and more considered as a possible solution to cover heating and cooling needs. They function according to the principle of shallow geothermal energy, exchanging heat with the ground. This results in a zone underground where the temperature of the ground is affected by the presence of the geothermal system, which is called thermal influence zone. As the number of energy geostructures increases, determining their thermal influence zone becomes crucial, especially in environments where adjacent energy geostructures or other geothermal systems coexist. Indeed, avoid or minimize the overlap between the thermal influence zones of different geothermal installations is important to ensure their efficiency. This study investigates the effects of groundwater level, thermal operation period, and ground permeability, in both heating and cooling modes, on the thermal influence zone generated around an energy tunnel. The results indicate that the thermal induced change in groundwater density and viscosity due to geothermal operations generates groundwater circular flows. These flows play a major role in shaping the thermal influence zone. In the heating mode (winter), when the groundwater is within the vicinity of the tunnel, i.e., above, at or just below the tunnel, the thermal influence zone takes an oval shape elongated below the tunnel invert. In the cooling mode (summer), the thermal influence zone does not follow a specific shape, and it is remarkably changed by the groundwater level. For instance, when the groundwater level is shallow, the thermal influence zone extends significantly upward, potentially overlapping with the surface layer affected by atmospheric air temperature. However, when the groundwater level at the tunnel centreline, the thermal influence zone takes a horizontal oval shape, which might interfere with adjacent similar installations. The expansion of the thermal influence zone is highly dependent on the operation duration. In winter, the downward elongation after 6 months operation reaches around 1.5 times that after 3 months.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100716"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144670356","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":"Energy evolution and distribution patterns of sandstone and its microscopic mechanism under multistage cyclic loading","authors":"Hongying Tan ,&nbsp;Hejuan Liu ,&nbsp;Chunhe Yang ,&nbsp;Haijun Mao ,&nbsp;Yujia Song ,&nbsp;Debin Xia ,&nbsp;Shengnan Ban ,&nbsp;Weimin Wang","doi":"10.1016/j.gete.2025.100694","DOIUrl":"10.1016/j.gete.2025.100694","url":null,"abstract":"<div><div>Sandstone, as a fundamental engineering material in depleted oil and gas reservoir gas storage systems, is susceptible to damage and failure under periodic stress disturbances. In this study, multi-level multi-cyclic loading tests were carried out on sandstone samples over the confining pressures range of 5–40 MPa, accompanied by real-time acoustic emission (AE) monitoring and periodic nuclear magnetic resonance (NMR) measurements. This study investigats the effects of confining pressure, stress level, and the number of cycles on energy evolution and energy distribution in rock, revealing the micromechanisms of energy evolution during cyclic loading. The results indicate that during the first cyclic loading, the input energy is primarily converted into dissipated energy through the compression of small pores and some medium pores. In subsequent loading cycles, the input energy is primarily converted into dissipated energy through the initiation and propagation of internal microcracks. Under high confining pressure, the rock transitions from brittle to ductile behavior, enabling it to withstand greater deformation. Additionally, at high confining pressure, rocks accumulate more strain energy, while energy dissipation is higher compared to lower confining pressures. Throughout the cyclic loading, dissipated energy consistently accounts for less than 30 % of the total input energy across all stress levels. The linear energy storage coefficient remains independence from stress level and cycle number, but exhibits an inverse relationship with confining pressure. There is an obvious linear relationship between rock dissipation energy and AE energy. Higher AE energy indicate that the rock dissipates more strain energy.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100694"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144288867","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":"Thermo-mechanical coupling damage constitutive relation of thermally treated rocks: Statistical modeling and verification","authors":"Peilei Zhang,&nbsp;Linqi Huang,&nbsp;Xibing Li","doi":"10.1016/j.gete.2025.100708","DOIUrl":"10.1016/j.gete.2025.100708","url":null,"abstract":"<div><div>Under the inherent high temperature conditions, the rock will obviously be damaged and deteriorated. Developing an objective and rational thermo-mechanical coupling constitutive model is the key to directly assess the rock strength and deformation behavior within a thermodynamic framework. The classical damage model, relying on the strain equivalent hypothesis, struggles to accurately describe the real nonlinear behavior at the compaction stage. For thermally treated rocks, this significantly leads to a larger evolution error. This paper introduces a strain correction method for obtaining effective strain by separating the compaction strain. On this basis, a novel thermo-mechanical coupling statistical constitutive model is developed. Compared to the classical and existing models, the proposed coupling constitutive model demonstrates superior capabilities in describing the uniaxial strength and deformation characteristics under constant heating and heating cycles, especially for the compaction and post-peak strain softening states. Furthermore, the thermo-mechanical coupling damage evolution is analyzed. As temperature increases, the initial damage increases, the experienced deformation also increases, and the overall damage development trends to be flat. In contrast, the influence of heating cycles on rock damage is more significant than that of direct heating. The integration of macroscopic thermodynamic degradation and statistical characterization in constitutive modeling is a reasonable analytical approach, with the parameters have clearly physical meaning. These results can serve as a reference for the thermodynamic constitutive theory in relation to deep rock engineering.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100708"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563912","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":"Hydromechanical simulation of argillaceous rocks: From laboratory tests to drift excavation","authors":"Davood Yazdani Cherati ,&nbsp;Jean Vaunat ,&nbsp;Antonio Gens Solé ,&nbsp;Carlos Plua ,&nbsp;Minh Ngoc Vu ,&nbsp;Gilles Armand","doi":"10.1016/j.gete.2025.100714","DOIUrl":"10.1016/j.gete.2025.100714","url":null,"abstract":"<div><div>This study aims to evaluate the role of the pre-peak hardening regime in an elasto- viscoplastic model for argillaceous rocks, called the argillite model, use the model to replicate the hydromechanical response of argillaceous rocks observed in both laboratory and field tests, and investigate the interactions between excavation supports and these geomaterials. Initially, the impacts of the pre-peak strain hardening regime on behavior of argillaceous rocks are investigated through modeling a series of theoretical biaxial tests. Afterward, the model is validated by simulating biaxial and triaxial tests conducted on Beaucaire marl and Callovo-Oxfordian (COx) clay samples, respectively. Additionally, the role of the hardening regime in capturing the dependence of strain at peak strength on confining pressure is demonstrated using the triaxial models. Next, the effects of the hardening regime on the hydromechanical response of argillaceous rocks to drift excavations are demonstrated by modeling GCS drift, excavated within the Meuse/Haute-Marne Underground Research Laboratory (MHM URL). Subsequently, the argillite model is employed to simulate three other supported and unsupported drifts, excavated within the MHM URL. Finally, the long-term failure pattern of the concrete lining is predicted. Results indicate that incorporating the hardening regime and support effects can significantly enhance the accuracy of the model predictions.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100714"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144655435","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":"Evaluation of acid fracturing in carbonatite geothermal reservoirs based on a coupled thermo-hydro-mechanical-chemical model considering discrete fracture networks","authors":"Jia Liu ,&nbsp;Wenqi Zhang ,&nbsp;Yi Xue ,&nbsp;Huimin Wang ,&nbsp;Shi-Tong Li ,&nbsp;Yun Zhang ,&nbsp;Weihua Li","doi":"10.1016/j.gete.2025.100704","DOIUrl":"10.1016/j.gete.2025.100704","url":null,"abstract":"<div><div>In the development of carbonate geothermal reservoirs, the implementation of acid fracturing technology is common and essential, effectively enhancing reservoir permeability. It encompasses a sequence of intricate phenomena including solute migration, acid-rock reaction, heat transfer, and deformation. Herein, a comprehensive thermo-hydro-mechanical-chemical (THMC) coupling model considering field-scale discrete fracture networks (DFNs) is established for the process. With the thin elastic layer and fracture element assumptions, the corrosion and deformation of fractures are considered simultaneously. Additionally, the model accounts for the corrosion effects of both bedrock and fracture surfaces, and tracks the evolution of fracture aperture and matrix porosity. Using the proposed model, this study investigates acid fracturing in varying reservoir and operational conditions. It is found that the connectivity of DFN can influence the seepage path of acid fluid, therefore affecting acid concentration transport, which has a significant impact on the reconstruction of reservoir acidification. The acidification effectiveness nonlinearly positively correlates to the rate and concentration of acid injection, while the change of chemical aperture is negatively correlated to the initial fracture aperture. Reservoir temperature has a limited influence on acidification outcomes. The scientific insights provided here are valuable in steering the optimization of acid fracturing in carbonatite reservoirs.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100704"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144322775","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":"Thermally induced tensile hoop stresses in energy piles: Implications for design and operation","authors":"Ugur Can Erginag ,&nbsp;Mert Guner ,&nbsp;Semra Polat ,&nbsp;Melis Sutman ,&nbsp;Ozer Cinicioglu","doi":"10.1016/j.gete.2025.100702","DOIUrl":"10.1016/j.gete.2025.100702","url":null,"abstract":"<div><div>Energy piles, also known as thermoactive piles, serve a dual purpose: providing structural stability and harvesting shallow geothermal energy. As such, their design must account for both structural and thermal loads. However, current practice typically considers only the axial components of thermal loads. This study aims to investigate thermal loads in three dimensions, with a particular focus on tensile hoop stresses in the clear concrete cover. Through numerical modelling, this study examines the positional and temporal variations of hoop stresses and elucidates the underlying mechanisms. The findings demonstrate that significant tensile hoop stresses can develop within the clear concrete cover during the operation of energy piles, and that these stresses shift positions with seasonal operational changes. Therefore, it is crucial to consider hoop stresses in the design of energy piles to prevent the exceedance of concrete’s structural tensile capacity, a major design concern. A sensitivity analysis was conducted, varying material properties, geometric aspects and operational preferences to identify the relationships between influential parameters and hoop stresses. The study concludes with design and operational recommendations based on these findings.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100702"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144314440","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":"Study on the fracture propagation rule of simultaneous fracturing under cyclic injection","authors":"Ge Zhu ,&nbsp;Chuanli Wei ,&nbsp;Jingna Liu","doi":"10.1016/j.gete.2025.100711","DOIUrl":"10.1016/j.gete.2025.100711","url":null,"abstract":"<div><div>Simultaneous fracturing has emerged as a pivotal technology in unconventional oil and gas development, offering significant advantages in enhancing operational efficiency and reducing costs. However, plagued by stress shadow, non-uniform propagation of multiple fractures may occur during the operation, resulting in the stimulated reservoir volume (SRV) failing to meet the requirements. This study proposes an innovative scheme of utilizing cyclic injection to alleviate stress shadow. The dynamic stress generated by cyclic injection can complicate the interaction of multiple fractures during propagation, increasing the complexity of the fracture network. Furthermore, a numerical simulation model of multi-fracture propagation during simultaneous fracturing under cyclic injection was established using the extended finite element method (XFEM). The impact of the temporal modulation parameters governing cyclic injection scheme, including period, amplitude and phase, on the fracture propagation was discussed. Finally, an operational scheme was proposed in which different operating wells use distinct cyclic injection rates during simultaneous fracturing. The results reveal that cyclic injection scheme can significantly alleviate the fracture propagation disparities caused by stress shadow compared to conventional constant injection mode. The period, amplitude, and phase of cyclic injection rate exert critical control over fracture propagation morphology during simultaneous fracturing operations. Notably, the implementation of different cyclic injection schemes for various operating wells represents a deliberate attempt to alleviate stress shadow and improve fracture complexity. The research results can provide guidance for the field application of simultaneous fracturing and significantly contribute to improving the SRV.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"43 ","pages":"Article 100711"},"PeriodicalIF":3.3,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144563913","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}