Xinping Li , Yingwei Zhu , Liangjun Wang , Dengxing Qu , Yi Luo , Fei Meng , Chenhao Pei , Wenhao Li
{"title":"Study on the micro-mechanical behavior and pore structure evolution mechanism of coral reef limestone based on digital rock core","authors":"Xinping Li , Yingwei Zhu , Liangjun Wang , Dengxing Qu , Yi Luo , Fei Meng , Chenhao Pei , Wenhao Li","doi":"10.1016/j.compgeo.2024.106845","DOIUrl":"10.1016/j.compgeo.2024.106845","url":null,"abstract":"<div><div>Coral reef limestone (CRL) is a type of marine carbonate rock that exhibits a highly developed pore structure. The pore structure exerts a considerable influence on the mechanical behavior and damage fracture process of CRL. In order to study the micro-mechanical behavior of CRL and its pore structure evolution mechanism, this paper is based on the digital core model of CRL obtained from CT scanning. The two-way transformation method of digital core – finite element model is employed to simulate and analyze the micro-element physical–mechanical behavior of porous CRL under quasi-static compressive loading. The mechanical parameters of the CRL skeleton were obtained through microphysical and mechanical experiments, and the HJC model parameters of the skeleton matrix were determined. This revealed the complex fracture mechanism of the CRL under the influence of pore structure. The study demonstrates that the CRL skeleton is primarily composed of aragonite, exhibiting an average elastic modulus of 76.97 GPa. The applicability of the HJC intrinsic model and its parameters is validated through nanoindentation simulation. The damage process of CRL is characterized by complex stress concentration, stress redistribution, and pore-induced fracture. The evolution of fracture extension is primarily influenced by the processes of pore closure, particle crushing and rearrangement, and micro-fracture initiation and propagation. The evolution of porosity is predominantly affected by the same factors, as well as the formation of micro-fractures and the expansion of existing ones. The non-uniformity of pore structure gives rise to the pronounced anisotropy and inhomogeneity observed in damage fracture.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106845"},"PeriodicalIF":5.3,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537708","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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 model for sediment transportation under breaking wave: The application exploration of VOF-CFD-DEM model in gas-fluid-particle system","authors":"Boen Li, Huihuan Ma","doi":"10.1016/j.compgeo.2024.106844","DOIUrl":"10.1016/j.compgeo.2024.106844","url":null,"abstract":"<div><div>The Computational Fluid Dynamics-Discrete Element Method (CFD-DEM) model integrated with the Volume of Fluid (VOF) method is applied to study the complex gas-fluid-particle coupled system. To enhance the model’s feasibility, the efficiency and accuracy improvement approaches are implemented into the model, including the coarse-grained method, porous medium replacement and semi-resolved method. To validate the effectiveness and accuracy of the model, simulations of the particle water entry and dam break scenarios are conducted, Subsequently, the VOF-CFD-DEM model is utilized to study the sediment transportation under breaking waves. A comparison of various turbulence models reveals that the stabilized <span><math><mrow><mi>k</mi><mo>-</mo><mi>ω</mi></mrow></math></span> model can simulate the breaking wave with acceptable efficiency and accuracy. The study examines the flow characteristics, forces acting on slopes, and typical sediment movements, providing detailed case studies and data relevant to gas-fluid-particle systems. This work extends the application of the VOF-CFD-DEM model to extreme conditions in ocean engineering, offering a mesoscopic perspective on complex engineering challenges.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106844"},"PeriodicalIF":5.3,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jinfeng Li , Zili Wang , Jidong Teng , Sheng Zhang
{"title":"Numerical prediction of frost heave in soils: The role of the ice lens initiation criterion","authors":"Jinfeng Li , Zili Wang , Jidong Teng , Sheng Zhang","doi":"10.1016/j.compgeo.2024.106833","DOIUrl":"10.1016/j.compgeo.2024.106833","url":null,"abstract":"<div><div>The criterion of ice lens initiation is a critical mechanical property that is essential for investigating the interactions between water and heat transport mechanisms in frost heave studies. Owing to the complexity of the ice lens initiation phenomenon, the criterion of ice lens initiation varies depending on different theoretical models, which makes uniform evaluation difficult. To investigate the intricate physical mechanism of the ice formation criterion, a unified theoretical model is proposed to simulate the ice formation process of four commonly used criteria (the neutral stress criterion, unfrozen water film criterion, pore ice pressure criterion and empirical water content criterion). The physical mechanisms of the different assessments are investigated by studying the frost heave, ice lens distribution and frost heave rate for four different soil properties. The results indicate that the neutral stress criterion is more accurate and stable for ice formation than the current well-established criterion for ice lens initiation. Furthermore, the study reveals significant similarities between the pore ice pressure and the unfrozen water film. The empirical water content is prone to significant errors because of the absence of a reliable physical basis.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106833"},"PeriodicalIF":5.3,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Indirect models for SWCC parameters: reducing prediction uncertainty with machine learning","authors":"Xuzhen He , Guoqing Cai , Daichao Sheng","doi":"10.1016/j.compgeo.2024.106823","DOIUrl":"10.1016/j.compgeo.2024.106823","url":null,"abstract":"<div><div>The soil–water characteristic curve (SWCC) is crucial for modelling the transport of water and hazardous materials in the vadose zone. However, measuring SWCC is often cumbersome and time-consuming. This paper introduces indirect models that predict SWCC parameters in probabilistic distributions using easily measurable quantities such as particle-size distributions and porosity. This paper starts with building a joint normal model and the derived conditional probability from it serves as a predictive model. However, this model had extremely high prediction uncertainty. To reduce such uncertainty, various machine-learning techniques were explored, including introducing the dependence of variation scale on predictors, using artificial neural networks (ANN) to model nonlinear dependence, incorporating additional predictive features, and generating a larger dataset. The final machine-learning model successfully reduces prediction variability and has been rigorously tested on a separate set of samples to prevent overfitting.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106823"},"PeriodicalIF":5.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537698","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Taiga Saito , Yu Otake , Stephen Wu , Daiki Takano , Yuri Sugiyama , Ikumasa Yoshida
{"title":"What defines a “site” in geotechnical engineering?: A comparative study between local and global big indirect databases","authors":"Taiga Saito , Yu Otake , Stephen Wu , Daiki Takano , Yuri Sugiyama , Ikumasa Yoshida","doi":"10.1016/j.compgeo.2024.106826","DOIUrl":"10.1016/j.compgeo.2024.106826","url":null,"abstract":"<div><div>Geotechnical engineering continuously faces the challenge of accurately assessing a wide array of physical properties from limited soil data. To solve this problem using a data-driven approach, this study introduced an innovative local big indirect database (Local-BID) based on extensive sampling of Tokyo seabed clay and compared it with a comprehensive global big indirect database (Global-BID) compiling data from numerous international sites. The comparison revealed that data variability in Local-BID and Global-BID was almost identical, thereby highlighting fundamental issues such as the definition of “site” and the concept of parameter variability in geotechnical engineering. Through meticulous analysis, we explored the influences of database selection, quantity of observation points, and estimation indicators on the outcomes of hierarchical Bayesian estimation. Interestingly, while the medians of our estimates remained stable across varying conditions, the variance was strongly affected by these factors. Moreover, we critically reassessed the “site” definition used in hierarchical Bayesian models, which typically groups sites based on planar proximity without considering vertical stratification. Although this definition can fundamentally function, our findings suggested that incorporating stratigraphic classifications to define subsites could enhance site characteristic assessments and aid in understanding site similarity through a detailed analysis of soil composition variations.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106826"},"PeriodicalIF":5.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Molecular dynamics simulations of the creep behavior of illite in the net-like red soils of Xuancheng, China","authors":"Mingwu Wang, Yuhan Zhang, Jiahui Yan, Feng Xiong","doi":"10.1016/j.compgeo.2024.106840","DOIUrl":"10.1016/j.compgeo.2024.106840","url":null,"abstract":"<div><div>The creep behavior of net-like red soils mainly depends on the micromechanical behavior of clay mineral atoms at the nanoscale. The 1M−tv configuration of illite determined by the experiments of XRD and SEM-EDS, was utilized to address the mechanical properties along various loading directions using the conventional molecular dynamics (MD) simulation method. Furthermore, a novel MD simulation method based on transition state theory was proposed to discuss temperature effects. Simulated results indicate that the ultimate stress value under tensile perpendicular to the illite layer is minimal relative to the transverse direction, the in-plane shear has more resistance to overcome than the transverse shear. Amounts of the tensile, compressive, and shear strengths of illite decrease with increasing temperature, while the strain of steady-state creep at the same loading applied time increases with the temperature. An energy barrier to enter the accelerated creep destruction phase is about 18 kcal/mol. Moreover, the improved MD simulation method can extend the time scale from 200 ps to 186 days. These results may conclude that the proposed MD simulation method may provide a powerful tool to investigate the creep behaviors of clay minerals at experimentally relevant timescales at the nanoscale.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106840"},"PeriodicalIF":5.3,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jian-Ping Li , Shui-Hua Jiang , Guo-Tao Ma , Mohammad Rezania , Mohaddeseh Mousavi Nezhad , Jian-Hong Wan
{"title":"Probabilistic evaluation of landslide influence zones considering stratigraphic dips and nonstationarity of soil properties","authors":"Jian-Ping Li , Shui-Hua Jiang , Guo-Tao Ma , Mohammad Rezania , Mohaddeseh Mousavi Nezhad , Jian-Hong Wan","doi":"10.1016/j.compgeo.2024.106815","DOIUrl":"10.1016/j.compgeo.2024.106815","url":null,"abstract":"<div><div>Accurate prediction of landslide movement is essential for effective disaster prevention and control. However, current studies on probabilistic large deformation analysis of landslides assume transverse anisotropy of soil, overlooking the impact of the soil fabric and depositional orientation on the post-failure behavior. While the specific effects of stratigraphic dips and nonstationary soil orientations on slope stability are frequently analyzed, these effects on the post-failure behavior of slopes have not been thoroughly explored. This study proposes a new probabilistic framework for simulating landslides and quantifying hazard zones, incorporating complex stratigraphic dips and two typical nonstationary soil orientations. The new method integrates nonstationary random field (RF) theory with the rotation of spatial autocorrelation structure. It derives formulas for calculating the thickness and depth of the soil layer at various locations, considering different stratigraphic dips and nonstationary orientations. This approach enables the simulation of parameter distributions for bedding and inverse soils with both vertical and stratigraphic nonstationarity. The generalized interpolation material point method (GIMP) is then used to simulate the post-failure behavior of slopes. The findings indicate that neglecting the spatial variability of soil parameters leads to an underestimation of the influence zone of landslide. Additionally, the nonstationary characteristics of soil parameters and stratigraphic dips can affect the failure mechanisms of slopes and the exceedance probabilities of runout and influence distances. The proposed method enhances the accuracy of predicting runout and influence distances, serving as a novel valuable tool for disaster management and mitigation.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106815"},"PeriodicalIF":5.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Incipient particle motion in the expansion of water-inrush channel by considering the 3D relative exposure degree","authors":"J. Wu, G.H. Dai, L.W. Zhang, L. Guo, H. Deng","doi":"10.1016/j.compgeo.2024.106842","DOIUrl":"10.1016/j.compgeo.2024.106842","url":null,"abstract":"<div><div>Water inrush is a high-risk disaster in the construction of water-rich tunnels. The loss of particles on the sidewall of the water inrush channel is the key factor. To study the incipient particle motion in the expansion of water-inrush channel by considering the 3D relative exposure degree, the analysis for incipient flow velocity of the water inrush channel is conducted. The BP neural network and triaxial test are used to get the mesoscopic parameters. Through the DEM–CFD coupling, numerical simulation for the incipient particle motion is implemented. The effects of the 3D relative exposure degree on the incipient flow velocity are analyzed. Finally, the incipient flow velocity in the expansion of water inrush channel is verified by the laboratory test and engineering field test. The results show that: (1) the large particles have greater incipient flow velocity; (2) the particles in large dip angle are easier to move; (3) the 3D relative exposure degree of particle conforms to the Weibull distribution and the exponential distribution; (4) the incipient flow velocity of particles is closer to the critical flow velocity of rolling instability; (5) the incipient flow velocity is determined by the particles at the bottom of expansion channel.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106842"},"PeriodicalIF":5.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536991","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Thermal effect on long-term behaviors of rocks: A DEM study","authors":"Yuan Sun , Chung Yee Kwok , Kang Duan","doi":"10.1016/j.compgeo.2024.106839","DOIUrl":"10.1016/j.compgeo.2024.106839","url":null,"abstract":"<div><div>Radioactive waste generates prolonged heating of surrounding rock in nuclear waste repositories, potentially causing continuous growth of cracks. To ensure the safe isolation of nuclear waste, it is imperative to investigate long-term heating effects on mechanical properties and time-dependent behavior of rocks. This study presents a temperature-dependent stress corrosion (T-SC) model based on the discrete element method (DEM), which incorporates thermal effects through grain expansion and temperature-dependent subcritical crack growth. Beishan granite specimens are generated, and microparameters are calibrated through uniaxial compression and creep tests. Then specimens are subjected to long-term heating with various temperatures (100–400 °C). Results indicate that uniaxial compression strength (UCS) and Young’s modulus (<em>E</em>) exhibit strengthening-weakening transitions under short- and long-term heating. The strengthening is attributed to a compacted microstructure resulting from grain expansion, while the weakening is due to an increased crack number. Furthermore, UCS and <em>E</em> decrease over time from short- to long-term heating due to subcritical crack growth. Besides, the time-to-failure decreases by 2–3 orders of magnitude and becomes less sensitive to stress, and stress thresholds decrease significantly from 70 % to 44 % of UCS with increasing temperature. These findings underscore the significant weakening effects of prolonged heating on rocks when temperatures exceed 200 °C.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106839"},"PeriodicalIF":5.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"On the use of a unified constitutive model for modelling slope large deformations with material point method","authors":"Bin Wang , Penglin Chen , Xia Li , Zixuan Zhang","doi":"10.1016/j.compgeo.2024.106838","DOIUrl":"10.1016/j.compgeo.2024.106838","url":null,"abstract":"<div><div>Landslides and debris flows can have devastating effects, particularly when movement involves a transition from solid-like to fluid-like process. The elastoplastic constitutive model has a limited ability to describe the entire movement process; thus, this paper establishes a unified constitutive model comprising a hypoplastic model and Bagnold model within a GPU-accelerated material point method (MPM) framework. The model is validated first through low-speed direct shear tests to demonstrate its ability to describe solid-state friction behaviour, then collision behaviour under rapid flow conditions is examined using high-speed annular shear tests. The validity of the unified model for geotechnical engineering large deformations is subsequently verified using column collapse, where the superiority of the unified model over the traditional constitutive model in describing the large deformation process is demonstrated. An index, the dynamic stress ratio, is comprehensively analysed over the whole column failure process and the dynamic stress ratio is found to correlate well with the second-order work conversion criterion, distinguishing the transition of movement from solid-like to fluid-like stage. Finally, the constitutive model is applied to a hazard assessment of the Qianjiangping and Tatopani landslides in which the applicability and stability of the model along with the MPM framework are further demonstrated.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106838"},"PeriodicalIF":5.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142537715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}