Geomechanics for Energy and the Environment最新文献

{"title":"A thermodynamically consistent model of strain coupling in expansive soils","authors":"Vicente Navarro ,&nbsp;Gema Urraca ,&nbsp;Gema De la Morena ,&nbsp;Erik Tengblad ,&nbsp;Laura Asensio","doi":"10.1016/j.gete.2025.100679","DOIUrl":"10.1016/j.gete.2025.100679","url":null,"abstract":"<div><div>This work examines the thermodynamic consistency of the relationship between the strains caused by the rearrangement of the microstructure in an expansive soil and the coupled plastic strains caused by the resulting rearrangement of the macrostructure (strain coupling). Assuming a multi-dissipative process, it is found that, for the energy variation associated with the mass exchange between macro- and microstructure to be consistent with the macroscopic strain dissipation, the strain coupling is determined by the macro- and microstructural constitutive relations, without the need to introduce new and additional external functions to define the coupling. This results in a robust definition of the coupling function under isotropic conditions, with a structure independent of the adopted constitutive models, which consequently does not have to be adjusted heuristically depending on the type of material, the test or whether microstructural swelling or shrinkage occurs.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100679"},"PeriodicalIF":3.3,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143903864","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":"3D numerical modelling and analysis of heat harvesting and pavement temperature regulation of a thermo-active road","authors":"Junjia Lyu,&nbsp;Nikolas Makasis,&nbsp;Liang Cui,&nbsp;Benyi Cao","doi":"10.1016/j.gete.2025.100678","DOIUrl":"10.1016/j.gete.2025.100678","url":null,"abstract":"<div><div>Thermo-active roads are a relatively new and underdeveloped type of energy geostructures. It involves two sets of horizontally placed pipes at different depths to exchange heat between the pavement surface and the ground. Thereby, thermal energy can be stored into the ground beneath the road in summer and can be extracted and used to heat up the road surface in winter to reduce freeze-thaw cycles. This research focuses on the development of a detailed three-dimensional (3D) finite-element (FE) model in COMSOL Multiphysics to explore the thermal performance of a thermo-active road. The 3D FE model developed was extensively validated against the experimental data from a full-scale field test undertaken in Toddington, UK. The validated model is further employed to analyse the effects of soil thermal conductivity, embedded depth of pipes, fluid flow rate and insulation layer on energy harvesting and extracting efficiency of the geothermal system. System optimisation is proposed based on the analysis. Results show that the embedded depth of storage pipes influences the energy harvesting efficiency the most, with energy storage increasing by 1.75 times when the embedded depth of storage pipes increased by 1.6 m. Higher soil thermal conductivity led to a higher energy harvesting efficiency of the system as well. The energy storage value increases from 0.56 to 0.86 MWh when soil thermal conductivity increased from 0.4 to 2.0 W⁄(m∙K). This research study indicates that this system can regulate road temperature, thereby potentially preventing road rutting in summer and freeze-thaw cycles in winter and extending its lifespan.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100678"},"PeriodicalIF":3.3,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143890700","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":"Development of experimental system for rock anisotropic seepage under true triaxial stress","authors":"Yixin Liu ,&nbsp;Yan Gao ,&nbsp;Gang Wang ,&nbsp;Weimin Cheng ,&nbsp;Chuanhua Xu ,&nbsp;Jiaxin Cheng","doi":"10.1016/j.gete.2025.100677","DOIUrl":"10.1016/j.gete.2025.100677","url":null,"abstract":"<div><div>In order to study the mechanical properties and anisotropic seepage behavior of rocks under complex stress conditions in deep strata, an anisotropic seepage dynamic monitoring system for true triaxial stress conditions was developed. In the process of research and development, four key technologies have been successfully broken through: (1) the use of an independently designed sealing system ensures complete sealing during seepage experiments, reduces experimental errors, and eliminates the edge effect through the six-axis linkage technology; (2) the specially designed multifunctional platen is capable of hydraulic fracturing, seepage, and data acquisition in the true triaxial experiments; (3) Integrated acoustic emission and seepage monitoring system, which can realize real-time dynamic monitoring of crack extension and seepage evolution under real triaxial stress conditions; (4) The control system supports real triaxial stress loading of up to 280 MPa, and it has a stress response sensitivity of 0.5 kPa/s, which ensures high-precision loading and monitoring. The crack extension modes of rocks under true triaxial stress conditions were systematically studied to reveal the dynamic relationship between crack extension and seepage paths. The results show that cracks preferentially extend in the direction of maximum principal stress, leading to a significant increase in seepage rate, while seepage rate lags in the direction of minimum principal stress due to the crack closure effect. A nonlinear \"rise-decline-rise\" dynamic relationship was observed between crack extension and seepage rate. This study provides new insights into the coupling mechanism between crack extension and seepage behavior under complex stress conditions.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100677"},"PeriodicalIF":3.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143869424","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":"Triaxial unloading effects on pre-holed sandstone energy characteristics and damage evolution mechanism: Comparative analysis of diffrent borehole bottom locations","authors":"Wenpu Li ,&nbsp;Yaoguang Chen ,&nbsp;Guorui Feng ,&nbsp;Xingxing Xie ,&nbsp;Minda Zhang ,&nbsp;Zhiyuan Tian ,&nbsp;Huan Zhang ,&nbsp;Tao Wang ,&nbsp;Ruiqing Hao ,&nbsp;Yun Bai","doi":"10.1016/j.gete.2025.100676","DOIUrl":"10.1016/j.gete.2025.100676","url":null,"abstract":"<div><div>Studying the failure mechanism of roof sandstone under the influence of drilling unloading and mining disturbance is crucial for preventing roof disasters and achieving safe and efficient mining in coal mines. Therefore, this research conducted unloading tests on sandstone with different borehole bottom location under varying radial stress gradients. First, the deformation and acoustic emission (AE) characteristics of sandstone during unloading were analyzed for different borehole bottom location. Next, the plastic and energy characteristics of the sandstone were examined and explained based on statistical damage theory. Finally, the damage mechanisms of sandstone under drilling pressure relief and support in the goaf with different borehole bottom location were discussed. The results indicate that different radial stress gradients have a detrimental effect on the mechanical properties of sandstone, and the depth of the hole exhibits a nonlinear degradation effect on these properties. By employing a damage constitutive model, energy evolution and acoustic emission characteristics validated the nonlinear degradation related to the borehole bottom location and effectively reflected the internal crack propagation in the rock. Appropriate borehole bottom location and support measures can effectively prevent roof fracturing while maintaining economic efficiency. This study aims to effectively mitigate damage to the roof under the influence of drilling unloading and mining disturbance, ensuring safe and efficient mining operations.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100676"},"PeriodicalIF":3.3,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143888142","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 interaction between pile and soil under lateral load in coral sand","authors":"Bingxiang Yuan ,&nbsp;Qingyu Huang ,&nbsp;Weiyuan Xu ,&nbsp;Zejun Han ,&nbsp;Qingzi Luo ,&nbsp;Guorong Chen ,&nbsp;Junhong Yuan ,&nbsp;Qiyong Zhang ,&nbsp;Sabri Mohanad Muayad Sabri","doi":"10.1016/j.gete.2025.100674","DOIUrl":"10.1016/j.gete.2025.100674","url":null,"abstract":"<div><div>In complex marine environments, research on the response of single piles to lateral loads under different coral sand grain sizes and different embedment depths of the pile body is relatively limited. This study employed indoor scaled-model tests combined with PIV technology, focusing on two variables: coral sand particle sizes and embedment depths of rigid piles. The effects on the bending moment of single piles, the resistance of coral sand, and the displacement of the pile shaft and pile top in coral sand layers were analyzed. The study also revealed the distribution and development patterns of horizontal strain in coral sand particles around the pile top when subjected to lateral loads. The results showed that, as particle size decreased, the maximum bending moment of the pile and the resistance of coral sand increased, the rotation point of pile displacement rose, and pile top displacement increased. In addition, smaller particles had weaker interlocking, resulting in less effective force chain transmission and lower load diffusion. When the embedment depth of the rigid pile decreased, lateral loads could not be transferred to deeper soil layers, leading to more noticeable displacements at the pile shaft and pile top.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100674"},"PeriodicalIF":3.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143826154","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":"Fracture properties and creep behavior of humic and sapropelic coals from nanoindentation measurements","authors":"Jianfeng Wang ,&nbsp;Huijuan Guo ,&nbsp;Zhongyang Ma ,&nbsp;Tian Liang ,&nbsp;Chao Yang ,&nbsp;Yuke Liu ,&nbsp;Peng Liu ,&nbsp;Dayong Liu ,&nbsp;Ping'an Peng ,&nbsp;Yongqiang Xiong","doi":"10.1016/j.gete.2025.100672","DOIUrl":"10.1016/j.gete.2025.100672","url":null,"abstract":"<div><div>The fracture properties and creep behavior of coal and its macerals play a critical role in coal mining and exploration, hydraulic fracturing operations, improving the efficiency of (enhanced) coalbed methane recovery, the implementation of geological carbon sequestration technology, and deep underground coal gasification technology. Previous researchers have mainly focused on micromechanical parameters such as Young's modulus and hardness, while it is currently unclear how organic macerals affect their fracture properties (fracture toughness (<em>K</em>_c), brittleness index (<em>B</em>)) and creep behavior of coal. Here, X-ray diffraction, Raman spectroscopy, and nanoindentation were used to investigate the microstructure, fracture properties and creep behavior of sapropelic and humic coals. Results show that the variation of fracture parameters (<em>K</em>_c and <em>B</em>) is similar to the variation of hardness and Young's modulus for different coal macerals. Humic coal exhibited higher brittleness index and creep parameters (viscoelastic parameters (<em>E</em>₁, <em>E</em>₂, <em>η</em>₁, and <em>η</em>₂), and contact creep modulus (<em>C</em>)) compared to sapropelic coal. In addition, the fracture parameters (<em>K</em>_c and <em>B</em>) and the creep parameters (<em>E</em>₁, <em>E</em>₂, <em>η</em>₁, <em>η</em>_2, <em>C</em>_, and creep stress exponent (<em>n</em>)) of coal macerals decrease in the order: inertinite &gt; vitrinite &gt; alginite. This suggests that the sapropelic coal and alginite with lower brittle were more prone to creep. The changes in the microfracture and creep parameters of coal maceral are mainly determined by its chemical structure. This study improves the understanding of the fracture properties and creep behavior in the coal and its matrix at the micro scale, which will provide theoretical guidance for optimizing coal seam fracturing and shed light on the creep mechanism of coal.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100672"},"PeriodicalIF":3.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847301","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":"Quantitative assessment of well leakage, part II: Case studies for CCS","authors":"Al Moghadam ,&nbsp;Sahar Amiri","doi":"10.1016/j.gete.2025.100675","DOIUrl":"10.1016/j.gete.2025.100675","url":null,"abstract":"<div><div>This paper presents the second part of a two-part series on estimating fluid migration along wells. We use the results of the model described in the first paper and outline a leakage calculation methodology. The present method considers the mechanical behaviour of the flow pathway, formation creep, visco-inertial effects, and the operational conditions of the well to provide a deterministic evaluation of fluid migration along the well. Two case studies are presented that focus on a CO₂ injection well in a depleted reservoir and a legacy well in an aquifer CCS project.</div><div>The results indicate that there is a pressure threshold below which CO₂ may not flow through the cemented annulus. Beyond that point, the flow rate increases non-linearly with storage pressure. The size of the leakage pathway changes over time with the pressure and temperature of the system and is not a static parameter. Visco-inertial effects and creep could reduce the potential leak rate. The computed rates should be considered as an upper bound in this work as the impact of multiphase flow was not considered. This type of assessment is critical to conduct quantitative risk assessments for CCS projects. The results enable operators to manage storage pressure, reduce the cost of MMV (Measurement, Monitoring, and Verification) plans, and improve well designs. We argue that the impact of the magnitude of leakage rates reported in this work should be weighed against the improvements to the economics of CCS projects with an increased pressure/storage capacity.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100675"},"PeriodicalIF":3.3,"publicationDate":"2025-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143838387","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 characteristics of coal pore structure changes during hot flue gas displacement and their impact on the gas displacement effect","authors":"Jiahao He ,&nbsp;Baiquan Lin ,&nbsp;Tong Liu ,&nbsp;Zhenyong Zhang ,&nbsp;Shuai Le ,&nbsp;Yajie Hu","doi":"10.1016/j.gete.2025.100673","DOIUrl":"10.1016/j.gete.2025.100673","url":null,"abstract":"<div><div>Gas displacement by hot flue gas injection into the coal body is a hot spot in the research on high-gas and low-permeability coal seams. Injecting hot flue gas generated by gas power plants into coal seams will introduce water and CO₂, and the introduced CO₂ will dissolve and ionize to form an acidic environment, leading to the dissolution of minerals in coal. Therefore, it is particularly important to study the impact of coal pore structure changes on gas displacement before and after mineral dissolution. In this study, the impact of mineral dissolution in coal was explored by combining Computed Tomography (CT) and COMSOL Multiphysics numerical simulation, and the parameters of the numerical model were determined based on gas adsorption-desorption experimental results. The following conclusions were drawn at the millimeter scale: (1) Compared with the Langmuir equation, the BET equation is more competent to act as an isothermal adsorption and desorption model of coal in high-gas and low-permeability coal seams. (2) After 10.11 % of minerals dissolve, the flow velocity and outlet flow rate in the fractures formed at the original positions of minerals both increase significantly, and the model permeability grows from 7.0711 × 10⁻¹² m² to 2.2331 × 10⁻¹¹ m². (3) The time consumed for the residual gas pressure to drop from its initial value to 0.1 MPa was calculated. (4) After mineral dissolution, the coal pore structure alters, resulting in changes in the distribution of gas pressure during displacement, and the gas pressure varies obviously spatially.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100673"},"PeriodicalIF":3.3,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143800013","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":"Development and validation of TOUGH-3DEC: A three-dimensional discontinuum-based numerical simulator for coupled thermo-hydro-mechanical analysis","authors":"Saeha Kwon,&nbsp;Kwang-Il Kim,&nbsp;Changsoo Lee,&nbsp;Jaewon Lee,&nbsp;Jin-Seop Kim","doi":"10.1016/j.gete.2025.100670","DOIUrl":"10.1016/j.gete.2025.100670","url":null,"abstract":"<div><div>The discontinuum-based numerical methods can simulate the coupled thermo-hydro-mechanical (THM) processes in porous media with multiple discontinuities, so it is appropriate to model the mechanical behavior of a fractured host rock under the coupled processes such as a geological repository for high-level radioactive waste. TOUGH-3DEC, a three-dimensional discontinuum-based simulator for the coupled THM analysis, was developed by linking the integral finite difference method TOUGH2 and the distinct element method 3DEC to describe the coupled THM processes in porous media and discontinuous media. TOUGH2 handles the coupled TH analysis through the internal simulation module, while 3DEC performs mechanical analysis based on the constitutive models of porous media and discontinuity, coupling the thermal and hydraulic responses from TOUGH2. The thermal and hydraulic couplings are key processes and should be carefully verified by sufficient cases, so this study performed TM and HM verifications by modelling analytic solutions including the uniaxial consolidation, fracture static opening, and the heating of a hollow cylinder. As comparative validations, two models describing laboratory-scale experiments regarding the HM and TM processes of fractured rock were simulated and compared to the experimental results. The developed TOUGH-3DEC simulator showed sufficient accuracy in reflecting the coupled THM processes of the small-scale discontinuous rock, but still needs to be verified by more complicated and large-scale coupled process problems to be applicable to the demonstration of the field-scale model requiring the coupled THM processes of various geological media, such as a multi-barrier system of a geological repository.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100670"},"PeriodicalIF":3.3,"publicationDate":"2025-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143815438","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":"Experimental study on the swelling pressure of compacted bentonite under high temperatures above 100 °C","authors":"Jang-Un Kim ,&nbsp;Hyunwook Choo ,&nbsp;Boyoung Yoon ,&nbsp;Susan E. Burns","doi":"10.1016/j.gete.2025.100671","DOIUrl":"10.1016/j.gete.2025.100671","url":null,"abstract":"<div><div>Disposal and storage of high-level nuclear waste in deep geological repositories requires understanding the behavior of compacted clay at high maximum design temperatures (&gt; 100 °C); however, the effect of temperature variations on the swelling pressure of compacted bentonite has generally been examined within a restricted temperature range of 20–90 °C. Consequently, this experimental investigation uses specially designed temperature-controlled apparatus to determine the swelling pressure of compacted Na-bentonite across a temperature span of 10–160 °C. The poro-thermal and chemo-thermal effects on the swelling pressure of bentonite were studied using three dry densities (1.20, 1.35 and 1.50 Mg/m³) and three electrolyte concentrations (de-ionized water, NaCl 0.1 M and 0.5 M solutions). A linear relationship was observed between the normalized swelling pressure (the ratio of swelling pressure at a specific temperature to the swelling pressure at 25 °C) and temperature under the tested temperature ranges, suggesting that the swelling pressure measured at relatively low temperature ranges (below 100 °C) could be used to estimate the high temperature (above 100 °C) swelling pressure based on extrapolation. The swelling pressure increased with temperature, and higher dry densities and lower electrolyte concentrations amplified this effect. The complex interplay of dry density, pore fluid concentration, and temperature on the swelling behavior of compacted bentonite was explained based on the competition between the interlayer and interparticle swelling pressures.</div></div>","PeriodicalId":56008,"journal":{"name":"Geomechanics for Energy and the Environment","volume":"42 ","pages":"Article 100671"},"PeriodicalIF":3.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807367","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}