Article
Geosciences, Multidisciplinary
Zhe Mao, Lianbo Zeng, Guangdi Liu, Guoping Liu, He Tian, Shaoqun Dong, Wenya Lyu, Mehdi Ostadhassan
Summary: This study utilized outcrops and the discrete element method (DEM) to simulate and analyze the characteristics, distribution patterns, and development mechanisms of natural fractures in the fault-bend fold. By integrating the deformation history with fracture types and development characteristics, a development pattern of fractures within the fault-bend fold has been established. The results provide guidance for locating favorable reservoirs in foreland thrust belts.
MARINE AND PETROLEUM GEOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Prashant K. Jha, Prathamesh S. Desai, Debdeep Bhattacharya, Robert Lipton
Summary: The study introduces a hybrid model called PeriDEM, which combines peridynamics and DEM to improve the performance and efficiency of engineering systems involving granular or particulate media. The model can simulate arbitrarily shaped particles and investigates the effect of mesh resolution on intraparticle peridynamics.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Physics, Fluids & Plasmas
Malith Prasanna, Arttu Polojarvi, Mingdong Wei, Jan Astrom
Summary: An investigation into modeling force transmission through fragmenting materials under compression, particularly sea ice, using the HiDEM model and laboratory-scale experiments on saline ice has led to the development of a new material model for fragmenting ice. By adjusting particle size, structure, and failure criterion, it was discovered that traditional ice modeling schemes are incomplete and shear failure is the dominant failure mode for fragmented ice under compression.
Article
Construction & Building Technology
Mohammad Zakerinejad, Masoud Soltani
Summary: The study investigates the compressive behavior of concrete members with Rectangular Continuous Transverse Reinforcement (RCTR) and found that RCTR can improve the compressive strength of RC members. A theoretical method based on Elasto-Plastic and Fracture (EPF) concrete model is proposed to predict the behavior of such members, which is in good agreement with the experimental results. The validity of existing design provisions in the compressive design of these members is also explored.
STRUCTURAL CONCRETE
(2021)
Article
Computer Science, Interdisciplinary Applications
Mengmeng Wu, Feng Zhou, Jianfeng Wang
Summary: In this study, discrete element method simulations were conducted on soil-rock mixture under mini-triaxial tests, taking into account the effect of particle shape. The deformation and failure characteristics of the mixture were analyzed, providing insights into the development of soil stabilization materials for geotechnical engineering.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Mechanical
Siyuan Yang, Duruo Huang
Summary: Three-dimensional discrete-element method (DEM) simulations are used to study the effect of particle shape on soil liquefaction. Two void fabric proxies, E-d and A(d), are proposed to quantify the anisotropy of particle-void cells. The evolution of E-d and A(d) during the entire liquefaction process and their effects on pre- and postliquefaction behaviors are investigated. Irreversible changes in fabrics and anisotropic load-bearing structures are quantified, and fabric-based criteria for jamming transition in flow deformation are proposed.
JOURNAL OF ENGINEERING MECHANICS
(2023)
Article
Chemistry, Multidisciplinary
Navaamsini Boopalan, Agileswari K. Ramasamy, Farrukh Nagi, Ammar Ahmed Alkahtani
Summary: This study compares several available optimization methods, including simulated annealing (SA), Genetic Algorithm (GA), Particle Swarm Optimization (PSO), and Pattern Search (PS) methods. The results show that in various failure tests, the PSO method reduced the Signal to Noise Ratio (SNR) value of the failed radiation pattern from 1 to 10 dB. This method also successfully generated a radiation pattern that closely matches the reference pattern before any failed elements are present in the array by optimizing the optimal weights of the remaining active elements in the array.
APPLIED SCIENCES-BASEL
(2021)
Article
Critical Care Medicine
Kyle H. Cichos, Brandon Boyd, Gerald McGwin Jr, Elie S. Ghanem
Summary: Acetabular fractures with transverse posterior wall patterns have a higher risk of infection after conversion total hip arthroplasty (THA) compared to other subtypes. Our study found that patients with transverse posterior wall fractures have an increased risk of infection within 1 year after conversion THA.
INJURY-INTERNATIONAL JOURNAL OF THE CARE OF THE INJURED
(2023)
Article
Chemistry, Physical
Yanling Zhao, Yuan Jin, Chengyi Pan, Chuanwang Wu, Xueyu Yuan, Gang Zhou, Wenguang Han
Summary: This paper investigates the wear of discrete grooves in cageless bearings using the discrete element method and proposes a new structural characteristic and bonding model to accurately characterize the wear degree of discrete grooves. It provides important theoretical guidance for cageless bearing design.
Article
Environmental Sciences
Mohammadreza Jalali, Ralf Brauchler, Mark Somogyvari, Remi de La Vaissiere
Summary: The Meuse/Haute-Marne Underground Research Laboratory provides a location for an experiment aimed at investigating the induced fracture network around tunnels. The study uses a combination of pneumatic tests and tomographic analysis to reconstruct the hydraulic properties and geometry of the fracture network. The results improve the understanding of the spatial geometry of the induced fracture network.
WATER RESOURCES RESEARCH
(2023)
Article
Energy & Fuels
Wenzheng Liu, Jun Yao, Qingdong Zeng
Summary: In this paper, a hydro-mechanical model for non-planar hydraulic fracture propagation in ductile formations is developed using the Drucker-Prager plasticity theory, Biot's theory, and cohesive zone model. The proposed model's accuracy and capabilities are demonstrated through several reference cases, and its numerical implementation is achieved through a hybrid XFEM-FVM-EDFM method. The influence of plastic deformation on simultaneous propagation of multi-fractures is investigated using the proposed model applied to two numerical cases.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Engineering, Mechanical
Maksym Dosta, Katrin Bistreck, Vasyl Skorych, A. Gerold Schneider
Summary: The application of mesh-free discrete element method for modeling of macroporous inverse opals is proposed in this study. The analysis shows that reducing porosity or adding a titania layer can improve mechanical properties, and the simulation results are in good agreement with previous studies. Despite the computational effort, the DEM-based approach demonstrates great potential for modeling complex-structured multicomponent materials.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Mechanics
C. Oliver-Leblond, R. Desmorat, B. Kolev
Summary: This study investigates the formulation of anisotropic damage model using discrete simulations, suggesting a beam-particle model for numerical characterization tests. The research shows that a second order damage tensor is sufficient to describe crack-induced anisotropy in practice, even when micro-cracks are strongly interacting. Additionally, an upper limit of the distance to the orthotropic symmetry class of bi-dimensional elasticity is obtained as a by-product of this work.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2021)
Article
Automation & Control Systems
Xiuqiong Chen, Xue Luo, Ji Shi, Stephen S-T Yau
Summary: This paper discusses the convergence of the continuous-discrete feedback particle filter (FPF) proposed by Yang et al. (2014), and proves that under certain conditions, the estimate of the algorithm will converge to the optimal estimate, with a detailed analysis of the estimation error bounds.
INTERNATIONAL JOURNAL OF CONTROL
(2022)
Article
Engineering, Mechanical
Koki Tazoe, Genki Yagawa
Summary: The study discusses the simulation of fatigue crack propagation using smoothed particle hydrodynamics for nonplanar crack propagation problems in a three-dimensional body. The proposed algorithm and model successfully matched experimental results, indicating its value in estimating nonplanar fatigue crack propagation in actual mechanical structures.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Engineering, Environmental
Guowen Xu, Chuan He, Jun Wang, Junbo Zhang
BULLETIN OF ENGINEERING GEOLOGY AND THE ENVIRONMENT
(2020)
Article
Engineering, Geological
Guowen Xu, Marte Gutierrez, Chuan He, Shimin Wang
Summary: This paper presents an equivalent continuum model to describe the mechanical behavior of transversely isotropic rocks, showing that the model can capture the transverse isotropy and damage distribution accurately. The model is verified through numerical simulation and used to reveal the non-uniform mechanical response of the surrounding rock and secondary lining in weak layered rock mass tunnel scenarios.
Article
Environmental Sciences
Soonkie Nam, Marte Gutierrez, Panayiotis Diplas, John Petrie
Summary: This paper critically compares the use of laboratory tests against in situ tests combined with numerical seepage modeling to determine the hydraulic conductivity of natural soil deposits. The results show that hydraulic conductivity values obtained by the in situ test better match the actual conditions in the field compared to laboratory tests.
Article
Engineering, Geological
Guowen Xu, Marte Gutierrez, Ketan Arora, Xin Wang
Summary: The study introduces a novel fractional damage visco-plastic model to describe the time-dependent behavior of rocks, successfully dividing the creep response into primary, secondary, and tertiary creep stages. The influence of time-dependent parameters on the deformation of surrounding rocks was revealed through the model's application, validating the reliability of the model.
Article
Engineering, Geological
Ketan Arora, Marte Gutierrez
Summary: This study proposes a new visco-elastic-plastic solution for deep circular tunnels in soft rock and high field stress conditions. By comparing with experimental data, it is found that the proposed solution accurately predicts tunnel wall displacement and reflects the time-dependent behavior of the tunnels.
INTERNATIONAL JOURNAL OF ROCK MECHANICS AND MINING SCIENCES
(2021)
Article
Engineering, Geological
Haotian Zheng, Christophe Bragard, Carlos Herranz Calvo, Michael Mooney, Marte Gutierrez
Summary: The Regional Connector Transit Corridor project in downtown Los Angeles involved constructing a complex and shallow cavern using the sequential excavation method. A systematic observational method was developed to improve real-time analysis and update risk knowledge during construction, leading to quality data review and prompt adaptations.
JOURNAL OF GEOTECHNICAL AND GEOENVIRONMENTAL ENGINEERING
(2021)
Article
Engineering, Geological
Ketan Arora, Marte Gutierrez, Ahmadreza Hedayat
Summary: The design of support systems for tunnels in squeezing ground conditions is a challenging task. This study develops a novel experimental setup using a physical model to simulate the tunnel excavation and support installation process in clay-rich rocks. The interaction between the support and the squeezing ground is observed to gain better understanding. The study proposes a time-dependent longitudinal displacement profile model for the supported tunnel and provides recommendations for optimizing the support requirement in squeezing ground conditions.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2022)
Article
Energy & Fuels
Tingting Yin, Dameng Liu, Yidong Cai, Marte Gutierrez
Summary: Understanding the gas transport mechanisms in fractured media is crucial for the exploitation of coalbed methane (CBM). In this research, a combined matrix and nano-fracture system based on the double-porosity model was constructed to provide molecular-level insights into the gas transport behaviors through simulation methods. The results showed that methane density in nano-fracture was higher than in matrix, with a significant equilibration time-lag. Gas molecules in the nano-fracture had high diffusion rates, while adsorption layers were formed in the transition area between matrix and fracture with increased densities. Compared to random movement in coal matrix, methane in nano-fracture and adsorption layers moved directionally along specific axes. The simulated diffusion coefficients aligned well with experimental data, demonstrating the efficacy of molecular simulation in characterizing the micro-transport properties of CBM molecules.
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2022)
Article
Engineering, Geological
Xiongyu Hu, Marte Gutierrez
Summary: This study proposed an analytical model for tunnels supported with tangentially yielding liners in viscoelastic ground. The model was validated by comparing calculated results with numerical simulation results. Parameter sensitivity analysis revealed the significant benefits of tangentially yielding liners in relieving overstress and improving the stability of tunnels. The yield efficiency of the liners depends on the yielding strength and deformable capacity of the yielding elements, with less dependence on installation time.
JOURNAL OF ROCK MECHANICS AND GEOTECHNICAL ENGINEERING
(2023)
Article
Computer Science, Interdisciplinary Applications
Haotian Zheng, Michael Mooney, Marte Gutierrez
Summary: This paper examines the capability of four surrogate modeling methods to accurately and efficiently capture the ground and structural deformations induced by SEM tunneling. A 3D finite-difference model and various statistical methods were used to simulate and analyze the deformation. The most suitable surrogate model was determined based on the accuracy and distribution of the output.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Environmental Sciences
Linan Liu, Wendy Zhou, Marte Gutierrez
Summary: This study applies the PSInSAR technique to measure ground subsidence related to a twin-tunnel excavation in downtown Los Angeles. The technique is suitable for urban areas and the vertical deformation rate is derived from SAR images. The results show local and uneven settlements up to approximately 12 mm/year along the tunnel alignment, with no severe damages to aboveground structures reported. The dominant contributing factor to the ground subsidence is the thickness of artificial fill and alluvium soils above the tunnel springline. Rating: 8 out of 10.
Article
Engineering, Mechanical
Zhengshu He, Chuan He, Gaoyu Ma, Wenbo Yang, Guowen Xu
Summary: This study presents a novel approach to estimate the structural performance of a deteriorated reinforced concrete shield tunnel, with a focus on the spatial correlation and variation of steel corrosion. A random field integrated with Gumbel model is used to simulate the nonuniform steel corrosion. Numerical and analytical models are developed to evaluate the load-bearing capacity of a corroded RC segment. Monte Carlo simulation is performed to estimate the failure probability of a deteriorated RC shield tunnel. An illustrative example investigates the effects of corrosion degree and nonuniformity of steel reinforcements on the structural performance.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Civil
Hongwei Fang, Yixiang Xu, Guowen Xu
Summary: The seismic slip line field theory (SLFT) is derived based on the method of characteristic, and the critical slope contour calculated by the SLFT is a convex shape when a high surcharge is imposed on the slope top surface. A simple and robustness failure mechanism is proposed to calculate the static and seismic ultimate bearing capacity of strip footing adjacent to the cohesion-frictional slopes where the critical slope contour shifts from the inside of the slope to the outside of the slope with the increase of the boundary load, and the slope is at the limit state when the critical slope contour is tangent to the slope surface. The influence of slope and footing geometric features, soil parameters, and the seismic load on the bearing capacity is analyzed. The ultimate bearing capacity decreases as the strength parameters decreases, and the slope angle and the seismic coefficient increases. The static and seismic bearing capacity calculated by the proposed method does not require the failure models to be initially assumed, and the results are consistent with those of the other methods.
KSCE JOURNAL OF CIVIL ENGINEERING
(2023)
Article
Engineering, Mechanical
Jiamin Du, Yueheng Shu, Guowen Xu, Chuan He, Chaofan Yao
Summary: This study used statical analysis, similarity model tests and numerical simulations to investigate the influence of geo-stress field on the evolution of lining cracks in soft rock tunnels. The results showed that circumferential crack was the most common type, followed by longitudinal, oblique, and reticulate cracks. The location and length of cracks were affected by the direction of the maximum principal stress. The stress redistribution and fracture pattern of the lining were more complex for larger cross-sectional areas. The study provides valuable insights for the structural design of secondary lining under different geo-stress fields.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Civil
Shuqi Ma, Marte Gutierrez
Summary: Shale is classified as a poroelastic material due to its unique behavior as a quasi-brittle material which remains undrained during typical loading conditions. Any model predicting the mechanical behavior of shale during loading must take into account these characteristics.
KSCE JOURNAL OF CIVIL ENGINEERING
(2021)
