Article
Engineering, Multidisciplinary
A. Jafari, M. Vahab, N. Khalili
Summary: A novel fully coupled hydro-mechanical model is used to assess the effect of fluid loss on the efficiency of fracturing treatment within saturated porous media. The model incorporates the formation of a cake layer, effects of filtrate, and independent pressure degrees of freedom. Numerical simulations demonstrate the framework's ability to model hydraulic fracturing in medium to low permeability formations.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2021)
Article
Computer Science, Interdisciplinary Applications
A. R. Khoei, S. M. S. Mortazavi, L. Simoni, B. A. Schrefler
Summary: There is evidence that fracture advancement in porous media can be smooth or stepwise, with pressure oscillations in saturated porous materials. The behavior is influenced by problem specifications and material properties, and not all numerical models can capture stepwise behavior. Cohesive models can model this behavior by satisfying a consistency condition for the numerical solution. Inhomogeneous media can exhibit irregular results in hydraulic fracturing, but the study shows that homogeneous media can also show such behavior. The extent of irregularity depends on the dynamic effects in the problem, and fracture forerunning contributes to stepwise fracture growth.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Multidisciplinary
Fang Shi, Daobing Wang, Xiaogang Chen
Summary: The study investigates the behavior and propagation mechanisms of hydraulic fractures in fracture-cavity reservoirs, finding that factors such as lateral stress coefficient, confining stress, in-situ stress difference, fluid viscosity, and fluid pumping rate all play a role in shaping the fracture path. Frictional natural fractures connected to cavities significantly alter stress distribution, causing hydraulic fractures to deviate from their original direction. Natural cavities between adjacent fracturing stages have a significant impact on stress distribution, leading to irregular fracture propagation paths.
CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES
(2021)
Article
Engineering, Multidisciplinary
Hui Li, Hongwu Lei, Zhenjun Yang, Jianying Wu, Xiaoxian Zhang, Shouding Li
Summary: A hydro-mechanical-damage fully coupled numerical method is developed for simulations of complicated quasi-brittle fracking in poroelastic media. The method combines fluid flow modeling in fractures and porous media using a unified fluid continuity equation with crack-width dependent permeability. The method is validated using analytical and experimental results, and is further applied to simulate horizontal wellbore fracking problems.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Computer Science, Interdisciplinary Applications
Yun Zhou, Diansen Yang
Summary: In this paper, a fast simulation method based on fully coupled XFEM is proposed to address the low efficiency and poor convergence in simulating the generation of complex fracture networks. The superiority of the proposed model in computational efficiency is demonstrated through numerical validation and analysis of several cases. The influence of key factors on the propagation of hydraulic fracture is investigated.
COMPUTERS AND GEOTECHNICS
(2022)
Article
Engineering, Geological
Cristian Mejia, Deane Roehl
Summary: This paper presents a numerical model of hydraulic fracture propagation in underground caving mines using an extended finite element method based on phantom nodes. Multiple hydraulic fractures along arbitrary paths are simulated, and the influences of in-situ stresses, fracture spacing, injection flow rate, and Young's modulus and permeability of the matrix are investigated. The results provide insights into the main parameters that affect fracture extension, which can be useful for optimizing the preconditioning process of underground block caving mines.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2023)
Article
Mechanics
Konstantinos Nikolakopoulos, Jean-Philippe Crete, Patrice Longere
Summary: This study develops a unified 3D numerical methodology for predicting the current residual strength of large metallic engineering structures under accidental overloads. The methodology combines the GTN model and XFEM/CZM coupling, showing promising results in reproducing ductile crack patterns and global specimen responses.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Computer Science, Interdisciplinary Applications
Fang Shi, Jishan Liu
Summary: Field data indicates that hydraulic fractures in shale gas reservoirs are three-dimensional and non-planar. A coupled model was developed in this study to simulate this phenomenon, focusing on reducing computational effort. The effectiveness of the proposed approach was demonstrated through examples and investigation into MPI parallel implementation.
COMPUTERS AND GEOTECHNICS
(2021)
Article
Mechanics
Konstantinos Nikolakopoulos, Jean-Philippe Crete, Patrice Longere
Summary: This study presents a unified 3D numerical methodology for predicting the current residual strength of large metallic engineering structures under accidental overloads. The methodology reproduces the progressive failure stages of ductile metal structures using the GTN model and XFEM/CZM coupling, and includes a transition criterion to account for competition between different types of localization. The performance of the methodology is evaluated through 3D numerical simulations of various loading cases, showing accurate ductile crack patterns and promising global specimen responses.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Mechanics
Konstantinos Nikolakopoulos, Jean-Philippe Crete, Patrice Longere
Summary: This study develops a unified 3D numerical methodology for predicting the current residual strength of large metallic engineering structures under accidental overloads. By combining the GTN model and XFEM/CZM coupling, the methodology successfully reproduces the progressive failure stages of structures made of ductile metals. The approach, implemented as a user element subroutine in ABAQUS, demonstrates mesh objectivity and accurate reproduction of ductile crack patterns, showing promising results for global specimen responses.
ENGINEERING FRACTURE MECHANICS
(2021)
Article
Engineering, Chemical
Qiquan Ran, Xin Zhou, Jiaxin Dong, Mengya Xu, Dianxing Ren, Ruibo Li
Summary: This study establishes a multi-hydraulic fracturing propagation model that considers rock damage, stress, and fluid flow, using the extended finite element method. The effects of horizontal stress difference and cluster spacing on fracture propagation are quantitatively analyzed. The results show that changes in stress difference and inter-cluster spacing significantly influence the final morphology of hydraulic fractures. The study also provides insights into the impact of inter-fracture interference on fracture propagation morphology.
Article
Energy & Fuels
Mahmoud Khadijeh, Alissar Yehya, Elsa Maalouf
Summary: This study analyzes the efficiency of hydraulic fracturing operations using numerical models and experimental studies. It finds that in vertically transversely isotropic (VTI) formations, the expansion of cracks is influenced by the degree of anisotropy. Additionally, cracks grow independently when the distance between cracks exceeds 12 m, and a planar propagation is observed for a distance above 20 m. The results also indicate that close cluster spacing leads to larger fractured area and resulting permeability. This work helps identify the optimal fracturing scenario for enhancing permeability in anisotropic unconventional reservoirs under different hydro-mechanical conditions.
GEOMECHANICS AND GEOPHYSICS FOR GEO-ENERGY AND GEO-RESOURCES
(2022)
Article
Engineering, Geological
Mohammad R. Mehraban, B. Bahrami, M. R. Ayatollahi, M. Nejati
Summary: One complexity in rock engineering is predicting fractures in rocks with anisotropy in both elastic and fracture properties. This study proposes a fracture criterion based on a stress averaging procedure using a combination of the extended finite element method (XFEM) and the cohesive zone model (CZM) to predict fracture growth in anisotropic rocks subjected to mixed mode I/II loadings. The precision of the proposed model is evaluated by comparing its predictions with experimental results on Grimsel granite, and the effects of important model parameters are discussed.
ROCK MECHANICS AND ROCK ENGINEERING
(2023)
Article
Engineering, Geological
Xun Xi, Zoe K. Shipton, Jackie E. Kendrick, Andrew Fraser-Harris, Julien Mouli-Castillo, Katriona Edlmann, Christopher McDermott, Shangtong Yang
Summary: The interaction between hydraulic fractures (HF) and natural fractures (NF) during hydraulic fracturing process has a significant impact on fluid flow, proppant transport, and well productivity. This paper presents a new fracture model to investigate the near-wellbore interaction and validates the model through numerical simulations. The results show that high injection pressure tends to drive HF to cross NF located close to the wellbore, while low injection flow rate can help activate natural fractures near the wellbore.
ROCK MECHANICS AND ROCK ENGINEERING
(2022)
Article
Engineering, Geological
Xun Xi, Shangtong Yang, Christopher I. McDermott, Zoe K. Shipton, Andrew Fraser-Harris, Katriona Edlmann
Summary: Soft cyclic hydraulic fracturing is an effective technology for subsurface energy extraction, inducing rock fatigue to reduce breakdown pressure and seismic risk. A numerical method is developed to model rock fracture induced by hydraulic pulses with consideration of rock fatigue. Experimental results validate the developed numerical model, showing that hydraulic pulses can reduce rock breakdown pressure by 10-18% upon 10-4000 cycles.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Thermodynamics
Saeed Salimzadeh, Hamidreza M. Nick, R. W. Zimmerman
Article
Energy & Fuels
Saeed Salimzadeh, Adriana Paluszny, Hamidreza M. Nick, Robert W. Zimmerman
Article
Green & Sustainable Science & Technology
Saeed Salimzadeh, Adriana Paluszny, Robert W. Zimmerman
INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL
(2018)
Article
Mechanics
Saeed Salimzadeh, Eirik D. Hagerup, Teeratorn Kadeethum, Hamidreza M. Nick
ENGINEERING FRACTURE MECHANICS
(2019)
Article
Energy & Fuels
S. Salimzadeh, H. M. Nick
Article
Green & Sustainable Science & Technology
S. Salimzadeh, M. Grandahl, M. Medetbekova, H. M. Nick
Article
Energy & Fuels
T. Kadeethum, S. Salimzadeh, H. M. Nick
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2019)
Review
Green & Sustainable Science & Technology
Adriana Paluszny, Caroline C. Graham, Katherine A. Daniels, Vasiliki Tsaparli, Dimitrios Xenias, Saeed Salimzadeh, Lorraine Whitmarsh, Jon F. Harrington, Robert W. Zimmerman
INTERNATIONAL JOURNAL OF GREENHOUSE GAS CONTROL
(2020)
Article
Engineering, Geological
M. K. Medetbekova, H. F. Christensen, S. Salimzadeh, R. R. Bakker, H. M. Nick
INTERNATIONAL JOURNAL OF GEOMECHANICS
(2020)
Article
Geosciences, Multidisciplinary
Saeed Salimzadeh, Robert W. Zimmerman, Nasser Khalili
GEOPHYSICAL RESEARCH LETTERS
(2020)
Article
Energy & Fuels
T. Kadeethum, S. Salimzadeh, H. M. Nick
Article
Engineering, Mechanical
Maiya Medetbekova, Helle F. Christensen, Frederic Amour, Saeed Salimzadeh, Hamidreza M. Nick
Summary: This study found that high-pressure jet drilling weakens the local mechanical properties of chalk, with acid-aided water having a greater impact on the chalk matrix, resulting in the formation of micro-perforations.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Engineering, Geological
Paromita Deb, Saeed Salimzadeh, Daniel Vogler, Stephan Dueber, Christoph Clauser, Randolph R. Settgast
Summary: This study aims to verify the numerical predictions of hydraulic stimulation experiments by comparing controlled laboratory experiments in granite samples to simulations using CSMP and GEOS. The results show that both simulators accurately reproduced the experimental pressure behavior, emphasizing the impact of fluid-loss and unsaturated flow on fracture pressure.
ROCK MECHANICS AND ROCK ENGINEERING
(2021)
Article
Engineering, Geological
Edoardo Pezzulli, Morteza Nejati, Saeed Salimzadeh, Stephan K. Matthai, Thomas Driesner
Summary: This article revisits the formulation of the J-integral in hydraulic fracture mechanics and presents two novel contributions. The first contribution is two variations of the J-integral that accurately predict viscosity-dominated propagation. The second contribution is a methodology to extract the propagation velocity from the energy release rate applicable throughout the toughness-viscous propagation regimes. These techniques are combined to form an algorithm capable of quickly converging on the location of the fracture front independently to the toughness-viscous regime of propagation.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2022)
Article
Water Resources
Saeed Salimzadeh, Dane Kasperczyk, Teeratorn Kadeethum
Summary: This study presents a fast and reliable machine-learned surrogate model to estimate the ground surface tilt induced by pressurised fractures. The testing results show excellent performance of the surrogate model compared with the forward finite element model for both single and multiple pressurised fractures, while running significantly faster.
ADVANCES IN WATER RESOURCES
(2023)
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)