Article
Geochemistry & Geophysics
I. R. Ashman, D. R. Faulkner
Summary: The composition of fault rocks, especially the proportion of clay, plays a crucial role in their frictional behavior and volume changes during fault slip. Clay-rich gouges exhibited measurable dilation upon a velocity increase, impacting the frictional strength and slip stability. This study provides essential insights towards understanding the slip behavior of faults, contributing to earthquake nucleation and sustained slow slip.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Nanoscience & Nanotechnology
Guangchang Yang, Yang Liu, Peipei Chen
Summary: This paper proposes a thermodynamic constitutive model to describe the thermal properties of saturated sand by introducing the concept of granular entropy and migration coefficient relationships. The theoretical energy dissipative structure composition and related migration coefficient relationships are determined, and the mathematical expressions for effective stress, plastic deformation, and granular temperature motion with temperature effect are deduced, establishing the relationship between temperature-induced mesoscopic energy dissipation and macro-mechanical behavior. The model's ability to describe the thermal properties of saturated sand is verified through comparison with simulation results and experimental data.
Article
Geochemistry & Geophysics
S. Parez, M. Kozakovic, J. Havlica
Summary: The pore pressure drop caused by fault dilatancy during accelerating slip may suppress earthquake nucleation. We conducted a physics-based model simulation of slip in saturated granular layers coupled to a fluid pressure reservoir. The grain rearrangements during slip induce rapid dilatation, generating the maximum pore pressure drop. The pore pressure drop is consistent with a prediction for incompressible fluid flow until the critical slip rate is reached, then it decays slowly, inhibits dilatation rate, and increases the layer's strength, stabilizing the rupture growth. The magnitude of the pore pressure drop depends on the drainage number and beta sigma '(n).
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Engineering, Geological
Qing-Yi Mu, Bao-Lin Dai, Chao Zhou
Summary: A new elastoplastic model for isotropic structured soils under saturated and unsaturated conditions was developed in this study, which incorporated the influence of soil structure on the loading collapse curve and its evolution during structure degradation. The model was successfully validated by simulating the behavior of structured and unsaturated soils along different suction and stress paths.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2023)
Article
Geochemistry & Geophysics
S. A. M. den Hartog, C. Marone, D. M. Saffer
Summary: The study of the Nankai subduction zone in southwest Japan is crucial for understanding fault and earthquake physics. Experiments on samples from Shikoku Island reveal the significant influence of temperature and slip velocity on stress distribution and frictional properties along subduction thrusts.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2023)
Article
Geochemistry & Geophysics
Marco M. Scuderi, Brett M. Carpenter
Summary: Observations of slow earthquakes and tremor have raised fundamental questions about the physics of quasi-dynamic rupture and the underlying fault zone processes. The presence of serpentinite suggests its important role in controlling complex fault slip behavior. Experimental results show the frictional behavior of serpentinite sampled from different locations, and highlight the significant influence of mineralogy on frictional stability and hydrological properties.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2022)
Article
Engineering, Geological
Lin-Yong Cui, Wei-Min Ye, Qiong Wang, Yong-Gui Chen, Bao Chen
Summary: Investigation of thermal effects on gas migration behavior in saturated bentonite materials is important for the safety assessment and efficiency evaluation of deep geological repositories. The experimental results reveal that capillary displacement and gas-induced pathway dilation play crucial roles in gas transport through compacted bentonite. Gas transport in saturated bentonite exhibits extremely slow movement, and the effective gas permeability is influenced by confining pressure and temperature. Moreover, the dominant mechanism for gas advection changes with temperature.
Article
Geochemistry & Geophysics
Nico Bigaroni, Marco Maria Scuderi, Frederic Cappa, Yves Guglielmi, Christophe Nussbaum, Luca Aldega, Giacomo Pozzi, Cristiano Collettini
Summary: The Opalinus Clay is an important potential sealing horizon for radioactive waste repositories and carbon storage. Laboratory experiments show that relative humidity, grain size, and normal stress affect the frictional properties and stability of fault analogues. Increasing humidity decreases the friction coefficient and increases the stability parameter, while increasing normal stress leads to a transition from localized to distributed deformation.
GEOPHYSICAL JOURNAL INTERNATIONAL
(2023)
Article
Engineering, Geological
A. Lashkari, S. R. Falsafizadeh, Md M. Rahman
Summary: This paper investigates the impact of volume change boundary conditions on the instability and post-peak softening of sand, revealing that volumetric expansion intensifies instability susceptibility while volumetric contraction reduces vulnerability. Experimental data analysis using Hill's second-order work criterion predicts relational trends for instability lines, normalized peak shear strengths, and maximum pore-water pressure ratios depending on the coupling between volumetric and shear strain rates. A simple state-dependent constitutive model is found to accurately predict relational trends in sand specimens experiencing instability and post-peak softening under different degrees of linear coupling between volumetric and shear strains.
Article
Engineering, Multidisciplinary
Eric C. Bryant, WaiChing Sun
Summary: This study utilizes a phase field framework to investigate the frictional slip of strong discontinuities in geological formations of different length scales, proposing a regularized constitutive law adjusted based on loading rates and temperature ranges. Numerical examples demonstrate that this model can capture the frictional response along complex interfaces.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Philipp Braun, Georgios Tzortzopoulos, Ioannis Stefanou
Summary: Laboratory experiments using sand-based 3D-printed materials were conducted to investigate frictional properties, bulk mechanical parameters, and viscous behavior. A special focus was placed on the post-peak softening behavior, with a model designed to simulate earthquake-like instabilities and oscillating friction coefficients during slip. The study also examined the creation of a gouge-like layer due to granular debonding during sliding, showing potential for new surrogate experiments in fault mechanics and geomechanics.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geosciences, Multidisciplinary
Alexey Ostapchuk, Kseniya Morozova, Vadim Markov, Dmitry Pavlov, Maxim Popov
Summary: The spectrum of fault slip modes ranges from fast ruptures to slow slip events, with mounting evidence that a single fault can host multiple modes. Laboratory experiments show a high inverse correlation between fault friction and the b-value of AE frequency-amplitude distribution. The self-organization of gouge-filled faults at the micro scale plays a key role in controlling the frictional behavior of faults with multiple slip modes.
FRONTIERS IN EARTH SCIENCE
(2021)
Article
Agricultural Engineering
Yufang Li, Mingsi Li, Hongguang Liu, Wenbao Qin
Summary: The study found that soil texture significantly affects drainage efficiency, with water moving quickly downwards in sandy soil, preventing it from entering the pipe, while water moves slower in loamy clay soil, allowing it to easily enter the pipe.
INTERNATIONAL JOURNAL OF AGRICULTURAL AND BIOLOGICAL ENGINEERING
(2021)
Article
Geochemistry & Geophysics
Benjamin D. Belzer, Melodie E. French
Summary: Chlorite, a phyllosilicate mineral, was studied to understand its role in fault slip. The experiments revealed that its frictional strength increases with temperature and transitions from rate-strengthening to rate-weakening behavior. The results suggest that the rate-weakening behavior is controlled by time-dependent properties of water adsorbed to mineral surfaces.
Article
Computer Science, Interdisciplinary Applications
Luyu Wang, Zhen-Yu Yin, Gang Han, Meilu Yu
Summary: This study investigates the temporal evolution characteristics during consolidation in fluid-saturated poroelastic media. A poroelastic model is established and a solution strategy based on differential operator method and series expansions is proposed. Different loading modes and boundary conditions are considered, and numerical tests are performed to explore the influences of drainage effect, loading modes, and material properties on the consolidation process.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Ocean
Chenpeng Song, Derek Elsworth, Sheng Zhi, Chaoyi Wang
Summary: Sporosarcina pasteurii (ATCC 11859) is a nitrogen-circulating bacterium capable of precipitating calcium carbonate, which can be applied in strengthening coastal foundations and preventing erosion. Research shows that particle morphology plays a critical role in microbially induced clogging mechanisms, with spherical particles having higher calcium carbonate content and angular particles leading to more effective permeability reduction.
MARINE GEORESOURCES & GEOTECHNOLOGY
(2021)
Article
Engineering, Geological
Sheng-Qi Yang, Wen-Ling Tian, Derek Elsworth, Jian-Guo Wang, Li-Feng Fan
ROCK MECHANICS AND ROCK ENGINEERING
(2020)
Article
Geochemistry & Geophysics
Mengke An, Fengshou Zhang, Zhaowei Chen, Derek Elsworth, Lianyang Zhang
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2020)
Article
Geochemistry & Geophysics
Hongwei Zhang, Zhijun Wan, Derek Elsworth
Article
Geochemistry & Geophysics
Zhiqiang Chen, Derek Elsworth, Moran Wang
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2020)
Article
Engineering, Geological
Adam K. Schwartzkopff, Atsushi Sainoki, Derek Elsworth
Summary: The study found that using the X-FEM method can efficiently predict fault mechanics due to fluid injection, demonstrating the accuracy and applicability of this approach in simulating fault mechanics.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Geosciences, Multidisciplinary
Mengke An, Fengshou Zhang, Ki-Bok Min, Derek Elsworth, Chris Marone, Changrong He
Summary: Research indicates that metamorphic minerals such as epidote and chlorite can influence the stability of faults in geothermal reservoirs, affecting frictional behavior and potentially leading to seismic activity. The presence of these minerals in fault gouges can destabilize slip and induce earthquakes, while also revealing a dependence of fault strength and stability on fault zone composition. Understanding the impact of these minerals on fault behavior is crucial for assessing earthquake triggering potential in geothermal systems.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Geosciences, Multidisciplinary
J. B. Zhu, J. Q. Kang, D. Elsworth, H. P. Xie, Y. Ju, J. Zhao
Summary: The study shows that cyclic fluid injection can reduce the magnitude and total energy of induced earthquakes, providing a way to potentially control the size of induced seismic events.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Energy & Fuels
Jianwei Tian, Jishan Liu, Derek Elsworth, Yee-Kwong Leong, Wai Li, Jie Zeng
Summary: Researchers characterized the structural heterogeneity of hydrofractured shale reservoirs at different hierarchical levels, including nanopore structure, micro-structure, natural fracture networks, and hydraulic fractures. The study demonstrated significant impacts of these heterogeneities on gas production.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Energy & Fuels
Junqiang Kang, Derek Elsworth, Xuehai Fu, Shun Liang, Hao Chen
Summary: This study analyzed the impact of water saturation on the permeability of coal reservoirs through experiments and finite element methods, finding that changes in E and v can lead to a faster or slower decrease in permeability, with E having a more significant effect on permeability.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2022)
Article
Geochemistry & Geophysics
Clay E. Wood, Parisa Shokouhi, Prabhakaran Manogharan, Jacques Rivere, Derek Elsworth, Chris Marone
Summary: The laboratory experiments investigated the relationship between nonlinear elasticity and permeability evolution in fractured media under local stress perturbations. The experiments, conducted with Westerly granite samples, revealed that oscillations of normal stress and pore pressure resulted in transient softening, acoustic velocity fluctuations, and changes in permeability. Alterations in fracture properties due to shearing decreased measured elastic nonlinearity and permeability change for stress and pressure oscillations.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2021)
Article
Geochemistry & Geophysics
Mengke An, Fengshou Zhang, Ki-Bok Min, Derek Elsworth, Changrong He, Luanxiao Zhao
Summary: This study investigates the impact of heterogeneity and contiguity of epidote-patch structure on frictional instability and finds that the mode of epidote precipitation controls the response of mixed gouges. The presence of epidote coatings on fractures/faults can enhance velocity-weakening behavior, supporting the potential seismic reactivation of faults.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
X. Sun, Y. Yao, D. Liu, D. Elsworth
Summary: This study investigates the mechanisms and relationships between CO2 adsorption and coal wettability by combining direct measurements and molecular dynamic simulations. The researchers find that coal wettability significantly weakens under increasing CO2 pressure. This study provides a robust method and results for accurately predicting CO2 storage capacity in coalbeds and enhanced methane recovery.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Fengshou Zhang, Rui Huang, Mengke An, Ki-Bok Min, Derek Elsworth, Hannes Hofmann, Xiaoguang Wang
Summary: Experiments on simulated granite fault gouges suggest that fluid injection can induce earthquakes, and variations in effective stress and mineral composition are important factors affecting fault strength and stability.
JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH
(2022)
Article
Geochemistry & Geophysics
Peng Dong, Rong Chen, Kaiwen Xia, Wei Yao, Zhigang Peng, Derek Elsworth
Summary: This study investigates dynamically triggered earthquakes on laboratory faults and reveals that the triggering process has two distinct phases, with a slow phase only present for a specific seismic condition and absent for supershear events.
SEISMOLOGICAL RESEARCH LETTERS
(2023)