Hasan Ghasemzadeh, Mohammad Ali Iranmanesh, Behnam Bagheri Charmkhoran
{"title":"Enriched EFG Method for Hydraulic Fracture Modeling in Multiphase Porous Media","authors":"Hasan Ghasemzadeh, Mohammad Ali Iranmanesh, Behnam Bagheri Charmkhoran","doi":"10.1002/nag.3919","DOIUrl":"https://doi.org/10.1002/nag.3919","url":null,"abstract":"The numerical investigation in this study focuses on the propagation of hydraulically driven fractures in deformable porous media containing two fluid phases. The fully coupled hydro‐mechanical governing equations are discretized and solved using the extended element‐free Galerkin method. The wetting fluid is injected into the initial crack. The pores are filled with both wetting and non‐wetting fluid phases. Essential boundary conditions are enforced using the penalty method. To model the discontinuities in field variables, the extrinsic enrichment strategy is employed. Ridge and Heaviside enrichment functions are utilized to introduce weak and strong discontinuities, respectively. The nonlinear behavior in front of the crack tip is defined by means of a cohesive crack model. Continuity equations for wetting and non‐wetting fluids through the fracture domain are expressed using Darcy's law and cubic law. The coupling terms of fluids are considered in accordance with their mass transfer among the crack and the surrounding domain, simulating the fluid leak‐off phenomenon and the fluid lag zone. The results demonstrate the success of the proposed numerical framework in simulating the intricate aspects of the hydraulic fracturing process. Sensitivity analysis is performed with varying domain permeabilities and wetting fluid viscosities to elucidate their effects on different aspects of hydraulic fracture.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"273 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142867029","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":"A Dynamic Three‐Field Finite Element Model for Wave Propagation in Linear Elastic Porous Media","authors":"Bruna Campos, Robert Gracie","doi":"10.1002/nag.3916","DOIUrl":"https://doi.org/10.1002/nag.3916","url":null,"abstract":"A three‐field finite element (FE) model for dynamic porous media considering the de la Cruz and Spanos (dCS) theory is presented. Due to fluid viscous dissipation terms, wave propagation in the dCS theory yields an additional rotational wave compared to Biot (BT) theory. In addition, introducing porosity as a dynamic variable in the dCS model allows solid‐fluid nonreciprocal interactions. Due to the volume‐averaging technique, the dCS model further accounts for a macroscopic shear modulus and adds a new macroscopic constant. The porous media governing equations are formulated in terms of solid displacement, fluid pressure, and fluid displacement. Space and time convergence rates for the FE dCS model are demonstrated in a one‐dimensional case. A dimensionless analysis performed in the dCS framework led to negligible differences between BT and dCS models except when assuming high fluid viscosity. Domains with small characteristic lengths resulted in BT and dCS damping terms in the same order of magnitude. One‐ and two‐dimensional examples showed that dCS nonreciprocal interactions and the macroscopic shear modulus are responsible for modifying wave patterns. A two‐dimensional injection well simulation with water and slickwater showed higher wave attenuation for the latter. High frequencies in dCS model were noticed to yield more significant changes in wave patterns. The numerical results highlight the contributions of the dCS porous media model and its importance in simulations of laboratory scale experiments, ultrasonic frequencies, and highly viscous fluids.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"23 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858231","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}
Kejie Tang, Minjie Wen, Yi Tian, Xingyi Zhu, Wenbing Wu, Yiming Zhang, Guoxiong Mei, Pan Ding, Yuan Tu, Anyuan Sun, Kaifu Liu
{"title":"A Multi‐Zone Axisymmetric Model for Consolidation of Saturated Soils Improved by PVTD With Interfacial Thermal Resistance","authors":"Kejie Tang, Minjie Wen, Yi Tian, Xingyi Zhu, Wenbing Wu, Yiming Zhang, Guoxiong Mei, Pan Ding, Yuan Tu, Anyuan Sun, Kaifu Liu","doi":"10.1002/nag.3922","DOIUrl":"https://doi.org/10.1002/nag.3922","url":null,"abstract":"During the process of treating soft soil foundations with prefabricated drainage drains (PVD), “soil columns” form around the PVD, and a “weak zone” forms outside the range of the “soil columns.” The difference in properties between the two forms a distinct interface, leading to a gradual decrease in drainage efficiency and obstruction of vertical drainage channels, which in turn causes cracks and lateral displacement in the soil during consolidation. The interfaces between adjacent soil layers are incomplete contact, and the water within the interstices impedes the transfer of heat, manifesting a thermal resistance effect. To address this phenomenon, a synchronous measurement system for the thermal gradient and the heat flux density between the soil interfaces has been developed. Applying Fourier's law of heat conduction, the thermal resistance coefficient has been determined. Based on the theory of thermo‐hydro‐mechanical coupling, a multi‐zone axisymmetric model for saturated soils that considers thermal resistance effect has been proposed. Semi‐analytical solutions were derived and validated through comparison with the custom FEM model and field experiments. The thermal consolidation characteristics of the multi‐zone soils under various thermal contact models have also been discussed, with a comprehensive analysis of the influence of different parameters. Outcomes show that: the generalized incomplete thermal contact model provides a better description of the thermal resistance phenomenon between multi‐zone soils interfaces; ignoring the thermal resistance effect leads to an overestimation of the deformation during the thermal consolidation, and, the thermal resistance effect decreases the influence of the thermo‐osmosis effect on the consolidation characteristics.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"86 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858234","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}
Diego Gutiérrez‐Oribio, Alexandros Stathas, Ioannis Stefanou
{"title":"AI‐Driven Approach for Sustainable Extraction of Earth's Subsurface Renewable Energy While Minimizing Seismic Activity","authors":"Diego Gutiérrez‐Oribio, Alexandros Stathas, Ioannis Stefanou","doi":"10.1002/nag.3923","DOIUrl":"https://doi.org/10.1002/nag.3923","url":null,"abstract":"Deep geothermal energy, carbon capture and storage, and hydrogen storage hold considerable promise for meeting the energy sector's large‐scale requirements and reducing emissions. However, the injection of fluids into the Earth's crust, essential for these activities, can induce or trigger earthquakes. In this paper, we highlight a new approach based on reinforcement learning (RL) for the control of human‐induced seismicity in the highly complex environment of an underground reservoir. This complex system poses significant challenges in the control design due to parameter uncertainties and unmodeled dynamics. We show that the RL algorithm can interact efficiently with a robust controller, by choosing the controller parameters in real time, reducing human‐induced seismicity, and allowing the consideration of further production objectives, for example, minimal control power. Simulations are presented for a simplified underground reservoir under various energy demand scenarios, demonstrating the reliability and effectiveness of the proposed control–RL approach.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"51 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142832151","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":"Probabilistic Assessment of Soil–Rock Mixture Slope Failure Considering Two‐Phase Rotated Anisotropy Random Fields","authors":"Chuanxiang Qu, Yutong Liu, Haowen Guo, Hongjie Fang, Kaihao Cheng, Haoran Yuan, Yong Chen","doi":"10.1002/nag.3921","DOIUrl":"https://doi.org/10.1002/nag.3921","url":null,"abstract":"Soil–rock mixture (SRM) slopes consist of soils and rocks and are widely distributed globally. In addition to heterogeneity and discontinuity within SRM slopes, the inherent spatial variability can be observed in soil and rock properties. However, spatial variability in rock and soil properties and layouts has not been well considered in the stability analysis of SRM slopes. Additionally, SRM slopes commonly show a rotated anisotropic fabric pattern, while such fabric has rarely been accounted for in SRM slope stability analysis. In this study, a two‐phase rotated anisotropy random field simulation method is proposed to model these spatial variations simultaneously. The proposed approach is then integrated with the finite element method (FEM) to study the impacts of soil volume fraction and bedding dip angle (i.e., rotated anisotropy) on the probability of failure (<jats:italic>p</jats:italic><jats:sub>f</jats:sub>) and failure mode of SRM slopes. It is found that considering only spatially varying layouts can underestimate <jats:italic>p</jats:italic><jats:sub>f</jats:sub> by up to 97% compared to considering both spatially variable properties and layouts. The increase in soil volume fraction significantly improves <jats:italic>p</jats:italic><jats:sub>f</jats:sub> and the likelihood of deep failure. The bedding dip angle greatly influences <jats:italic>p</jats:italic><jats:sub>f</jats:sub>, yet deep failure remains dominant across different bedding dip angles. Furthermore, the failure mode of SRM slopes is more sensitive to the changes in soil volume fraction than to bedding dip angle.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"43 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142832152","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}
Erick Rógenes, Ian Torras Paes, Bruno Guimarães Delgado, Rafael Jabur Bittar, Alessandra dos Santos Gomes, Alessandro Cirone, Alomir H. Fávero Neto, Leandro Lima Rasmussen
{"title":"Assessing Static Liquefaction Triggers in Tailings Dams Using the Critical State Constitutive Models CASM and NorSand","authors":"Erick Rógenes, Ian Torras Paes, Bruno Guimarães Delgado, Rafael Jabur Bittar, Alessandra dos Santos Gomes, Alessandro Cirone, Alomir H. Fávero Neto, Leandro Lima Rasmussen","doi":"10.1002/nag.3914","DOIUrl":"https://doi.org/10.1002/nag.3914","url":null,"abstract":"Static liquefaction‐induced failure in tailings dams can result in extensive economic and environmental damage. In practice, the use of constitutive models capable of capturing this phenomenon and assessing structures susceptible to liquefaction is increasing. Numerous constitutive models exist and have been applied to model static liquefaction of tailings materials, but the extent of the influence exerted by the choice of constitutive model on analysis outcomes remains to be determined. This study addresses this uncertainty by employing the Clay and Sand Model (CASM) and NorSand models to analyze the well‐documented case of the B1 dam failure in Brazil. Initially, a back analysis of the failure was conducted, and further analyses were carried out by simulating hypothetical triggers: crest loading and increased gravity. The influence of the adopted constitutive model on results was analyzed through the failure mechanisms generated, stress paths, and levels of disturbances necessary to trigger liquefaction. Both models produced compatible failure mechanisms, with slight differences observed in the level of disturbance required to trigger liquefaction. The results obtained from the B1 case indicate that the most important aspect related to the constitutive model in assessing structures susceptible to static liquefaction lies in the constitutive model's capacity to represent the sudden strength loss due to pore pressure generation, while the particular formulations employed in each method tend to be a secondary consideration in the analysis.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"13 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142820745","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}
Lun Hua, Yi Tian, Yue Gui, Wenlian Liu, Wenbing Wu
{"title":"Semi‐Analytical Study of Pile–Soil Interaction on a Permeable Pipe Pile Subjected to Rheological Consolidation of Clayey Soils","authors":"Lun Hua, Yi Tian, Yue Gui, Wenlian Liu, Wenbing Wu","doi":"10.1002/nag.3915","DOIUrl":"https://doi.org/10.1002/nag.3915","url":null,"abstract":"Permeable pipe pile, a novel pile foundation integrating drainage and bearing functions, improves the bearing capacity of the pile foundation by accelerating the consolidation of the soil around the pile. In this study, a mathematical model is established to simulate the consolidation of surrounding clayey soils and the pile–soil interaction, where the rheological properties of the soils are described with the fractional derivative‐based Merchant model, and the impeded drainage boundary is used to simulate the pile–soil interfacial drainage boundary. Corresponding solutions for pile–soil relative displacement, skin friction, and axial force on the pile shaft are derived by means of semi‐analytical methods, and they are validated by comparing with experimental results and numerical simulation results. Based on the proposed semi‐analytical model, a series of parametric analyses are conducted to investigate the influences of fractional orders, viscosity coefficients, pile–soil interface parameters, and pile‐head loads on the pile–soil interaction characteristics. It is observed that during the transition stage, the axial force increases linearly with depth in the plastic segment, and then increases nonlinearly in the elastic segment until it decreases after reaching the neutral plane. In the elastic segment, the axial force on the pile shaft for a given time increases with the increases in the fractional order or the pile–soil interface parameter, but decreases with the increase of viscosity coefficient.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"29 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815772","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":"Numerical Modeling on Small‐Strain Stiffness and Viscoelastic‐Viscoplastic Characteristic of Soft Soils","authors":"Zhi Yong Ai, Gan Lin Gu, Jun Tao Yuan","doi":"10.1002/nag.3918","DOIUrl":"https://doi.org/10.1002/nag.3918","url":null,"abstract":"The behavior of soft soils distributed in coastal areas usually exhibits obvious time‐dependent behavior after loading. To reasonably describe the stress‐strain relationship of soft soils, this paper establishes a viscoelastic‐viscoplastic small‐strain constitutive model based on the component model and the hardening soil model with small‐strain stiffness (HSS model). First, the Perzyna's viscoplastic flow rule and the modified Hardin–Drnevich model are introduced to derive a one‐dimensional incremental Nishihara constitutive equation. Next, the flexibility coefficient matrix is utilized to extend the one‐dimensional model to three‐dimensional conditions. Then, by combining the HSS elastoplastic theory with the component model, the viscoelastic‐viscoplastic small‐strain constitutive model is subsequently established. To implement the proposed model for numerical analysis, the corresponding UMAT subroutine is developed using Fortran. After comparing the results of numerical simulations with those of existing literature, the reliability of the constitutive model and the program written in this paper is verified. Finally, numerical examples are designed to further analyze the effects of small‐strain parameters and viscoelastic‐viscoplastic parameters on the time‐dependent behavior of soft soils.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"4 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142815821","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}
Qingyang Ren, Senlin Gao, Songqiang Xiao, Xin Meng, Zhongyao Li
{"title":"Macroscopic and Mesoscopic Damage Characteristics and Energy Evolution Laws of Rock Mass With Double Arcuate Fractures Under Uniaxial Compression","authors":"Qingyang Ren, Senlin Gao, Songqiang Xiao, Xin Meng, Zhongyao Li","doi":"10.1002/nag.3917","DOIUrl":"https://doi.org/10.1002/nag.3917","url":null,"abstract":"In order to reveal the influence of double arc‐shaped fissure dip angles on the macro‐micro failure and energy evolution laws of rock masses, a numerical model of red sandstone was firstly established using the PFC2D. Moreover, mesoscopic parameters of the numerical model were calibrated based on the uniaxial compression tests on intact and single straight fissure red sandstone specimens. Then, particle flow simulation tests of red sandstone with different arc‐shaped fissure dip angles were carried out. The results show that the peak strength and elastic modulus both increase with the increase of arc‐shaped fissure dip angle <jats:italic>α</jats:italic>, exhibiting an oblique shear‐tensile failure pattern. Six types of cracks evolved during the instability and rupture of the rock mass with double arc‐shaped fissures. The macroscopic fissures in the rock mass ultimately penetrate along the extension direction of the arc‐shaped fissures. As the arc‐shaped fissure dip angle <jats:italic>α</jats:italic> increases, the crack evolution is positively correlated with the acoustic emission (AE) of the specimen. When approaching instability failure, the AE ringing count rapidly increases. There is a critical angle limit inflection point for the total energy absorbed by the rock between 60° and 75°, with a total energy increase of about 54%. During instability failure, it is dominated by dissipative energy, with elastic energy as a supplement. This article derived a damage constitutive model of red sandstone with different arc‐shaped fissure dip angles, revealing the damage laws of red sandstone under different arc‐shaped fissure dip angles.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"47 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809228","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}
Kang Yang, Mengmeng Lu, Yuanjie Liu, Xueyu Geng, Zhiwei Ding
{"title":"Theoretical Study on Consolidation of Slurry Treated by PHDs‐VP Considering Clogging Effect and Vacuum Preloading Process","authors":"Kang Yang, Mengmeng Lu, Yuanjie Liu, Xueyu Geng, Zhiwei Ding","doi":"10.1002/nag.3912","DOIUrl":"https://doi.org/10.1002/nag.3912","url":null,"abstract":"Prefabricated horizontal drains combined with vacuum preloading (PHDs‐VP) have addressed the shortcomings of prefabricated vertical drains combined with vacuum preloading (PVDs‐VP), beginning to emerge as a popular method for dredged slurry treatment. However, theoretical research on PHDs‐VP consolidation is relatively scarce. This study proposes a novel analytical model for predicting the consolidation behavior of the slurry treated by PHDs‐VP. This model treats the PHDs layer as a continuous drainage layer. Analytical solutions considering the clogging effect and the vacuum preloading process have been derived. The correctness and applicability of the proposed model have been verified through degeneration analysis and comparison with laboratory experimental data. Subsequently, an in‐depth sensitivity analysis of parameters has been conducted to assess the influence on consolidation. The research findings indicate that the clogging effect significantly reduces the consolidation rate, while the influence of the increasing rate in vacuum pressure is relatively minor. Additionally, increasing the slurry filling rate and the PHDs layout density can both accelerate soil consolidation. These findings offer significant guidance for the implementation of PHDs‐VP method in engineering.","PeriodicalId":13786,"journal":{"name":"International Journal for Numerical and Analytical Methods in Geomechanics","volume":"82 1","pages":""},"PeriodicalIF":4.0,"publicationDate":"2024-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142809225","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}