Article
Engineering, Geological
M. Williams, M. Ziegler, Stephan Schennen, S. Loew
Summary: The text presents the results of seismic experiments conducted in two excavation damaged zones (EDZs) in Mont Terri Underground Rock Laboratory. The findings provide valuable insights into the integrity of the rock mass surrounding the excavation and its implications for mid-term safety assessments.
ENGINEERING GEOLOGY
(2022)
Article
Geochemistry & Geophysics
Sina Hale, Xavier Ries, David Jaeggi, Philipp Blum
Summary: In this study, a hydromechanical characterization of an evolving excavation damaged zone (EDZ) in the Mont Terri underground rock laboratory in Switzerland was conducted using three different handheld devices. The study found permeable fractures with specific hydraulic apertures, observed cyclic long-term fracture aperture oscillations, and determined the uniaxial compressive strength of the rock. The study's methodological approach is suitable for time-dependent monitoring of EDZs, providing spatially resolved investigation of hydraulic and mechanical fracture apertures, surface roughness, and rock parameters.
Article
Geosciences, Multidisciplinary
Ke Man, Xiaoli Liu, Zhifei Song
Summary: The study conducted blasting tests in the Beishan Exploration Tunnel and monitored blasting vibration velocity and excavation damaged zone, identifying the impact of different blasting parameters on vibration velocity and damaged depth, and proposing a method to control rock damaged depth.
GEOMATICS NATURAL HAZARDS & RISK
(2021)
Article
Engineering, Geological
Wenbo Pan, Zixin Zhang, Shuaifeng Wang, Qinghua Lei
Summary: In this study, a seismo-hydro-mechanical simulation was conducted to analyze the impact of earthquakes on the hydrogeological properties of a nuclear waste repository. The simulation results showed that the changes in fracture transmissivity induced by earthquakes follow a power-law decay.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2023)
Article
Engineering, Geological
Philipp Braun, Pierre Delage, Siavash Ghabezloo, Baptiste Chabot, Nathalie Conil, Minh-Ngoc Vu
Summary: This study reproduces complex coupled thermo-hydromechanical (THM) loading paths in the laboratory to investigate the behavior of clay rocks under the conditions of geological radioactive waste repositories. By controlling radial and axial stresses, pore pressure, and temperature using a specially designed triaxial system, the study is able to maintain axial effective tension on the specimens. The results show that the fracture of clay rocks under effective tension occurs at an average stress of around 3.0 MPa.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Chemistry, Multidisciplinary
Barbara Pastina, Jay A. LaVerne
Summary: This passage discusses the importance of long-term safety assessment of spent nuclear fuel disposal in deep geologic repositories, and presents a conceptual model to explain radionuclide release rates. It suggests that current estimations of radionuclide release rates may be overestimated, and provides suggestions for future research directions.
APPLIED SCIENCES-BASEL
(2021)
Article
Energy & Fuels
Tao Meng, Pei Jianliang, Gan Feng, Yaoqing Hu, Zhijiang Zhang, Dengke Zhang
Summary: This study investigates the evolution of permeability and porosity of salt rock-gypsum interlayers in a coupled thermo-hydro-mechanical-chemical (THMC) environment. The results show that the permeability and porosity of the gypsum specimens vary non-monotonically with increasing temperature, and the degree of damage plays a significant role in determining the variation trends.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Materials Science, Multidisciplinary
Huatao Zhao, Ming Tao, Xibing Li, Zhixian Hong, Rui Zhao, Wenzhuo Cao
Summary: The existence of excavation damaged zone (EDZ) influences the stability of underground openings. This study investigates the fracture evolution and dynamic mechanical properties of holed rock specimens with damage zones under dynamic loads. The results show that the strength decreases and the failure mode changes with increasing damage around circular holes.
INTERNATIONAL JOURNAL OF DAMAGE MECHANICS
(2022)
Article
Engineering, Geological
Junhong Huang, Xiaoqing Wei, Yi Luo, Hangli Gong, Tingting Liu, Xinping Li
Summary: This study investigated the deformation and failure of surrounding rock mass triggered by sudden changes of rock quality encountered in a tunnel excavation project, focusing on the geological disasters caused by fracture zones. The findings from a field case analysis of the Daliang Tunnel in China revealed the deformation profiles of the surrounding rock mass at different distances from the fracture zone. The relationship between the deformation of the surrounding rock mass in the fracture zone and the materials, length of advanced support, and excavation advance rate was also explored. The study emphasized the significance of controlling rock mass deformation in fracture zones.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Geosciences, Multidisciplinary
Lukas M. Keller
Summary: The role of surface roughness in fractures is important for understanding the hydromechanical behavior, with different closure mechanisms affecting permeability and fracture compliance. Fracture surfaces in Opalinus Clay show fractal-like characteristics, while different closure mechanisms have varying effects on hydromechanical properties. Plastic deformation plays a significant role in fracture closure by compression in clay rocks, with simulations predicting permeability changes with different confining pressures.
FRONTIERS IN EARTH SCIENCE
(2022)
Article
Engineering, Geological
Kazuhei Aoyagi, Eiichi Ishii, Youqing Chen, Tsuyoshi Ishida
Summary: This study evaluates the sensitivity of fracture aperture to shear displacement in excavation-damaged-zone (EDZ) fractures by observing resin-preserved EDZ fractures. The results show that fracture aperture is insensitive to shear displacement, which can be reproduced by a previously reported empirical relationship.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Geological
Yu Deng, Xuanmei Fan, Gianvito Scaringi, Dongpo Wang, Siming He
Summary: This study evaluates the efficiency of thermochemical pressurization in carbonate rockslides using mass and energy conservation equations. The results indicate that the permeability of the rock wall controls pore pressure evolution and the efficiency of thermal decomposition. This study is important for understanding the hypermobility of large landslides in carbonate rock.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Materials Science, Ceramics
Kimbal T. Lu, Yingjie Zhang, Tao Wei, Gabriel L. Murphy, Aurpa Bhuiyan, Nicholas Scales, Rongkun Zheng
Summary: This study presents a comprehensive investigation on lanthanide monouranate-based glass-ceramic composites as potential waste forms for the immobilization of lanthanide actinide fraction waste. The results show that the crystalline LnUO(4) precursor can be well stabilized in a sodium aluminoborosilicate glass, while the in situ crystallization of EuUO4 from oxide precursors is robust under various processing conditions. Microscopic observations reveal different microstructures, and diffuse reflectance spectroscopy confirms the presence of pentavalent uranium.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Water Resources
D. M. Brooks, L. P. Swiler, E. Stein, P. E. Mariner, E. Basurto, T. Portone, A. Eckert, R. Leone
Summary: This paper introduces the use of the Geologic Disposal Safety Assessment Framework and demonstrates how it addresses the challenges of high uncertainty and limited computational resources. The effects of spatial heterogeneity on system behavior are investigated using global sensitivity analysis and ratios of water fluxes. The results show that spatial heterogeneity is the main uncertainty in predicting repository performance.
ADVANCES IN WATER RESOURCES
(2022)
Article
Chemistry, Analytical
Xiaorong Wan, Chuan Li, Zhengang Zhao, Dacheng Zhang, Yingna Li, Jiahong Zhang
Summary: A Fiber Bragg Grating stress sensor was developed in this study to measure stress variations in rock, with applications in safety monitoring and stability prediction in underground coal mines. The sensor compensates for environmental temperature disturbances and has shown sensitivity to stress changes in the Excavation Damaged Zone. Monitoring results indicate that the sensor is effective in measuring stress amplitudes and creep times during blasting, providing important data for mine safety.
Article
Engineering, Geological
Mengsu Hu, Jonny Rutqvist
Summary: This study presents multi-scale modeling capabilities developed based on the numerical manifold method for analyzing coupled hydro-mechanical processes in fractured rocks. Fractures are modeled as continua-finite-thickness porous zones, discontinua-discontinuous interfaces, and microscale asperities and granular systems based on their geometric features. The simulations demonstrate the significant contribution of contact dynamics to geometric, multi-physical evolution in rough fractures systems.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Geological
Mengsu Hu, Jonny Rutqvist, Carl Steefel
Summary: This paper introduces the use of neural style transfer (NST) to generate mesh from rock fracture images, achieving a good balance between the density of the mesh and the presentation of geometric features through optimizing the cost function. This new approach shows efficient mesh generation and optimization by learning both content and style from the input images.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2021)
Article
Multidisciplinary Sciences
Iman Rahimzadeh Kivi, Estanislao Pujades, Jonny Rutqvist, Victor Vilarrasa
Summary: The study shows that thermal stresses resulting from water circulation through a doublet in a hot sedimentary aquifer can destabilize faults located far away from the doublet. Additionally, the timing of fault reactivation is mainly controlled by fault permeability, emphasizing the importance of employing appropriate characterization methods.
SCIENTIFIC REPORTS
(2022)
Article
Engineering, Geological
Xuhai Tang, Siji Tao, Ping Li, Jonny Rutqvist, Mengsu Hu, Lei Sun
Summary: In this study, the mechanisms of frost cracking as a result of freeze-thaw cycling, confining stress, and the interaction of multiple cracks were investigated using experimental, theoretical, and numerical approaches. The experimental and numerical results showed that frost cracks tend to propagate in the direction of maximum principal stress, and the position and orientation of initial cracks significantly influence the interaction effect between two frost cracks.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Geochemistry & Geophysics
Keurfon Luu, Martin Schoenball, Curtis M. Oldenburg, Jonny Rutqvist
Summary: This study uses a coupled multiphase fluid flow and geomechanical simulator to model the fluid pressure and stress changes during CO2 injection, and investigates the impact of CO2 injection on faults in crystalline basement rock. The results show that considering poroelastic stress changes is crucial for accurately modeling the seismicity rate.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Computer Science, Interdisciplinary Applications
Jiangmei Qiao, Xuhai Tang, Mengsu Hu, Jonny Rutqvist, Zhiyuan Liu
Summary: This study found that in carbonate fracture-cavity reservoirs, natural fractures have a dominant impact on the propagation of hydraulic fractures, followed by the influence of confining stress. These two factors are critical to the design of hydraulic fracturing in carbonate fracture-cavity reservoirs.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Engineering, Geological
Xuhai Tang, Yiheng Zhang, Jingjing Xu, Jonny Rutqvist, Mengsu Hu, Zhengzhi Wang, Quansheng Liu
Summary: Scientists have developed a new method, using microscale rock mechanics experiments (micro-RME) results, to determine the macroscale mechanical properties of arbitrarily shaped granite. This method has been proven to be a breakthrough from the conventional technology of macro-RME by using test specimens from small and arbitrarily shaped rock fragments.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Engineering, Geological
Tsubasa Sasaki, Jonny Rutqvist
Summary: Safety assessment of geological nuclear waste repositories is essential. This study investigates the effect of time-dependent deformation of shale on the long-term integrity of a generic subsurface nuclear waste repository. Results suggest potential advantages of constructing repositories in high creep shale.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2022)
Article
Computer Science, Interdisciplinary Applications
H. Tounsi, J. Rutqvist, M. Hu, R. Wolters
Summary: This study analyses the flow of brine in rock salt using a fully coupled THM model that considers non-isothermal two-phase flow through deformable porous media. The experimental data and model predictions show good agreement, and suggest that it is important to consider the coupling between heating-and cooling-induced damage and flow properties to estimate brine inflow accurately. This modeling approach will be helpful for designing the cooling phase in salt repositories to minimize damage and brine inflow.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Geosciences, Multidisciplinary
I. R. Kivi, R. Y. Makhnenko, C. M. Oldenburg, J. Rutqvist, V. Vilarrasa
Summary: This study develops a computationally efficient transport model to investigate the dynamic process of the basin-wide upward migration of CO2 in a multi-layered geological environment. The results show that significant leaks of CO2 are unlikely to occur, ensuring the security of underground storage.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Geochemistry & Geophysics
J. J. Xu, Y. H. Zhang, J. Rutqvist, M. S. Hu, Z. Z. Wang, X. H. Tang
Summary: Understanding the thermal effects on rock is critical for geothermal resource exploration and understanding Earth's temperature-driven evolution. This study observed the thermal-induced microcrack propagation of granite in real time using an ultrahigh-temperature instrument on an optical microscope. The experimental results revealed that microcracks initiate at 300°C and coalesce between 400 and 600°C, which is the main reason for the sharp decrease in macroscale mechanical properties of granite.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Thermodynamics
Allan Katende, Jonny Rutqvist, Cody Massion, Mileva Radonjic
Summary: Global energy systems are transitioning to clean energy sources to reduce carbon dioxide emissions, necessitating the exploration and development of shale gas resources to support the global supply of natural gas. The challenge lies in the low permeability of shale, requiring large-scale volume fracturing to enhance connectivity. This study investigates the influence of a thin proppant layer on a single fracture and explores the effects of rock mineralogy, surface roughness, fluids, confining stress, time, temperature, and bedding on proppant embedment in Caney shale. The experiment revealed that fracture conductivity is primarily affected by proppant layer, roughness, mineralogy, fluids, temperature, and closure stress.
Article
Energy & Fuels
Allan Katende, Connor Allen, Jonny Rutqvist, Seiji Nakagawa, Mileva Radonjic
Summary: The current global energy supply is insufficient to meet the increasing demand, resulting in soaring energy prices. Shale oil and gas, although non-renewable, are relatively clean energy resources and still dominate the energy market. This paper investigates the stress-dependent changes in hydraulic conductivity and mechanical fracture-proppant interactions in Caney Shale, finding that proppant size is crucial for improving fracture conductivity.
Article
Engineering, Geological
Hafssa Tounsi, Jonny Rutqvist, Mengsu Hu, Ralf Wolters, Svetlana Lerche
Summary: Rock salt is a potential host for heat generating nuclear waste due to its self-sealing capacity, low permeability, and high thermal conductivity. The geologic disposal of larger-sized canisters originally designed for spent fuel storage and transportation is being considered as a cost-effective alternative; however, their long-term vertical movement and low-stress creep behavior need to be evaluated. Different creep models were compared and the results showed that models calibrated only against high-deviatoric stress data might lead to inaccurate estimations of canister movement in salt formations.
Article
Computer Science, Interdisciplinary Applications
Yinghao Deng, Yang Xia, Di Wang, Yan Jin
Summary: This study investigates the mechanism of hydraulic fracture propagation in laminated shale, develops a numerical solver, and validates the effectiveness of the method through simulation experiments. The study also examines the influence of the interaction between hydraulic fractures and weak interfaces on the mechanical properties of shale.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Zhichao Zhang, Mingfei Feng, Guangshuo Zhou, Zhenglong Xu
Summary: A thermodynamic constitutive model for structured and destructured clays is proposed in this paper. The model includes state-dependent relations of hyperelasticity and plasticity without the concept of yielding surface. The proposed model captures the couplings between elasticity and plasticity and the effects of bonding structure.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Deze Yang, Xihua Chu
Summary: Creep and stress relaxation behaviors in granular materials are influenced by the time-dependent changes in their microstructure, with particle shape playing a significant role. However, the effects of particle shape on these behaviors are still not well understood. In this study, 3D DEM models incorporating the rate process theory and superellipsoids are used to simulate creep and stress relaxation in granular samples with different aspect ratios and blockiness. The results show that both aspect ratio and blockiness have a significant influence on creep and stress relaxation, with aspect ratio affecting creep through contact force ratio and blockiness affecting stress relaxation through variation in normal contact force anisotropy. These findings provide insights into the effects of particle shape on creep and stress relaxation in granular assemblies.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Shahab Amanat, Kourosh Gholami, Reza Rafiee-Dehkharghani, Dipanshu Bansal
Summary: This paper investigates the optimal design of wave barriers using the modified non-dominated sorting genetic algorithm-II (NSGA-II) and the Bloch-Floquet theory. The aim is to find the optimal design of plane wave barriers with a wide bandgap at a low-frequency range and low construction cost. The study develops a modified NSGA-II algorithm to determine the optimal arrangement of concrete in wave barrier unit cells. The performance of the optimal barriers is examined through finite element simulation and their efficacy in attenuating plane S-waves is verified.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Yanlin Su, Guoqing Cai, Fengjie Yin, Yepeng Shan, Annan Zhou
Summary: This paper presents a novel elastic-viscoplastic constitutive model that takes into account particle breakage to reproduce the time-dependent behavior of coarse-grained soil. The model integrates the Unified Hardening (UH) model, the elastic-viscoplastic (EVP) model, and the overstress theory. The relationship between particle breakage and loading rate is established, and state variables associated with the critical state of coarse-grained soil are derived to consider both time and particle breakage. A three-dimensional elastic-viscoplastic constitutive model is constructed by combining a one-dimensional viscoplastic hardening parameter with a secondary consolidation coefficient considering particle breakage. The proposed model requires 19 parameters and effectively describes the influence of time-dependency and particle breakage on the shear, dilatancy, and compression behaviors of coarse-grained soil with different confining pressures or initial void ratios. Experimental data comparisons validate the model's ability to replicate the time-dependent behavior of coarse-grained soil.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Shichao Zhang, Yaqiong Wang, Qidong Gao, Xiaobo Ma, Haixiao Zhou, Zhifeng Wang
Summary: Accurately evaluating and predicting ground settlement during tunnel excavation is essential for ensuring tunnel stability. This study conducted a probabilistic analysis of ground settlement under uncertain soil properties. The results demonstrate that spatially variable soils significantly influence the ground settlement in the vertical direction.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Xu Zhang, Bin Luo, Youjun Xu, Zhiwen Yang
Summary: This paper presents an analytical solution for horizontal displacements induced by small radius curve shield tunneling. The formula is derived based on the image method and Mindlin solution, considering additional thrust, frictional resistance, ground loss, and grouting pressure. The solution is validated with on-site data, demonstrating its reliability and providing a new approach for predicting and controlling stratum horizontal displacements in curve shield tunneling. The study finds that ground loss has the most significant influence on displacements, and soil closer to the tunnel exhibits larger horizontal displacements.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jian-Hong Wan, Ali Zaoui
Summary: Ground vibrations during earthquakes can cause soil strength loss and structural damage. Rubber-soil mixtures (RSM) have shown promise in reducing residual ground deformation. This study used molecular dynamics simulations to investigate the friction behavior of the rubber-clay interface in RSM systems. The results revealed a direct correlation between normal stress and friction force, with denser soil systems exhibiting higher friction forces.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Hongying Wang, Qiang Zhang, Peinan Wu, Yanjing Li, Lijun Han, Guilei Han
Summary: In addition to the Mohr-Coulomb and Hoek-Brown criteria, other nonlinear functions are used to describe the plastic response of rock mass. This paper derived the equivalent cohesive strength, frictional angle, and dilatancy angle for nonlinear yield and plastic flow rock masses. The solution for a circular tunnel in any nonlinear yield and plastic flow rock masses was derived and verified using a numerical procedure. The analysis of strain-softening rock masses under two assumed nonlinear yield criteria was also studied.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Zhijun Wu, You Wu, Lei Weng, Mengyi Li, Zhiyang Wang, Zhaofei Chu
Summary: This study proposed a machine learning approach to predict the uniaxial compression strength (UCS) and elastic modulus (E) of rocks. By measuring meso-mechanical parameters and developing grain-based models, a database with 225 groups of data was established for prediction models. The optimized kernel ridge regression (KRR) and gaussian process regression (GPR) models achieved excellent performance in predicting UCS and E.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Mingjun Zhou, Zhenming Shi, Chong Peng, Ming Peng, Kahlil Fredrick E. Cui, Bo Li, Limin Zhang, Gordon G. D. Zhou
Summary: In this paper, the erosion and deposition processes during overtopping dam breaching are simulated using a novel method (ED-SPH). The proposed model is able to capture the complex behaviors of dam soil erosion, entrainment, and depositions. Soil deposition hinders particle movement and reduces water velocity at the water-soil interface.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
C. Chavez-Negrete, F. J. Dominguez-Mota, R. Roman-Gutierrez
Summary: To accurately simulate groundwater flow in porous layered media, it is important to consider all environmental factors and use a generalized finite differences scheme as a meshless method for spatial discretization. This approach ensures robustness and accuracy of the numerical solution.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Shuairun Zhu, Lulu Zhang, Lizhou Wu, Lin Tan, Haolong Chen
Summary: This paper investigates the effectiveness of the cascadic multigrid method applied to the improved Picard iteration method for solving nonlinear problems in deforming variably saturated porous media. Two improved Picard iteration methods are proposed, and their effectiveness is verified through numerical examples. The results show that the improved methods have faster convergence and higher computational efficiency compared to the classical method.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Yuan Cao, Yan-Guo Zhou, Kyohei Ueda, Yun-Min Chen
Summary: Investigated shear stress responses of enclosed soil in deep soil mixing (DSM) grid-improved ground, and revealed the characteristics of the waist effect and mathematical model for shear stress reduction ratio.
COMPUTERS AND GEOTECHNICS
(2024)
Article
Computer Science, Interdisciplinary Applications
Jinfan Chen, Zhihong Zhao, Jintong Zhang
Summary: This study develops data-driven criteria to estimate the peak shear strength (PSS) of rock fractures, considering the effects of surface roughness features. A high-quality dataset is created using particle-based discrete element method and diamond-square algorithm. Tree-based models and convolutional neural network are trained to predict the PSS of rock fractures, and their reliability is verified using experimental data.
COMPUTERS AND GEOTECHNICS
(2024)