Computers and Geotechnics最新文献_第6页

An optimization DEM modelling method for soil-fibre undrained cyclic loading tests model based on the influence range of fibre 基于纤维影响范围的土壤-纤维排水循环加载试验模型的优化 DEM 建模方法

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-24 DOI: 10.1016/j.compgeo.2024.106846

Xiaohua Bao , Zhizao Bao , Jun Shen , Xiangsheng Chen , Hongzhi Cui

The computational cost of discrete element modelling is high owing to the limitations of particle size and contact in fibre modelling. This paper proposes an optimised discrete element method (DEM) for a hybrid model of soil and fibres based on the fibre influence range. First, a relative velocity state function is established based on the relative motion state between the fibres and soil particles under undrained cyclic loading. Subsequently, the influence range of the fibres is determined using the relative velocity function based on the first few cycles of the undrained cyclic loading numerical tests. Cluster and clump models of the fibre are then generated based on the influence range of the fibre. Finally, a symmetrical shape of the optimised model is developed by extracting the distribution length of the edge curve of the influence range along the vertical direction of the axis. In this study, the proposed optimised DEM was validated through a series of undrained cyclic loading numerical tests on fibre-reinforced soil. The results of the optimised model were highly consistent with those of the traditional model, and the computational time was significantly reduced. The cyclic loading timing for determining the range of influence of the fibre was analysed. The optimised model based on the influence range of the 15th cycles not only restored almost the same results but also saved the calculation cost by nearly eight times. The optimised model established based on the influence range after the 15th cycles had a slight influence on the results. In addition, the applicability of the optimised model is discussed. This paper provides new insights into the establishment of a hybrid model of soil and fibres.

由于纤维建模中颗粒大小和接触的限制，离散元建模的计算成本较高。本文提出了一种基于纤维影响范围的土壤与纤维混合模型的优化离散元方法（DEM）。首先，根据不排水循环荷载下纤维与土壤颗粒之间的相对运动状态，建立相对速度状态函数。随后，根据不排水循环加载数值试验的前几个循环，利用相对速度函数确定纤维的影响范围。然后，根据纤维的影响范围生成纤维的簇和团块模型。最后，通过提取影响范围边缘曲线沿轴线垂直方向的分布长度，建立对称形状的优化模型。在本研究中，通过对纤维加固土壤进行一系列排水循环加载数值试验，验证了所提出的优化 DEM。优化模型的结果与传统模型的结果高度一致，而且计算时间显著缩短。分析了确定纤维影响范围的循环加载时间。基于第 15 次循环影响范围的优化模型不仅恢复了几乎相同的结果，还节省了近 8 倍的计算成本。根据第 15 次循环后的影响范围建立的优化模型对结果有轻微影响。此外，还讨论了优化模型的适用性。本文为土壤和纤维混合模型的建立提供了新的见解。

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引用次数: 0

The effect of particle size distribution on the collapse of wet polydisperse granular materials 粒度分布对湿式多分散颗粒材料塌陷的影响

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-23 DOI: 10.1016/j.compgeo.2024.106854

Yisong Wu, Hu Tang, Yuantao Zhang, Dengming Wang

Low-saturation liquid-containing granular materials are commonly encountered in both natural and industrial settings, where interstitial liquids significantly affect the motion of particles, while particle size polydispersity plays a crucial role in determining the level of system cohesion. In this study, the collapse of wet polydisperse granular columns is numerically investigated based on the developed discrete element model, with corresponding dam-break experiments performed to validate our numerical model and methodology. The dependence of the dynamics and flow mobility on particle size distribution is primarily examined, and the underlying mechanisms are also explored by analyzing particle path lengths and average fidelity. Building upon the effective Bond number proposed using the mixing theory, a macroscopic cohesion parameter at the material scale is defined by considering the dependence of the collapse on the system size effect. The relevance of this cohesion parameter in describing different wet polydisperse granular collapses is further validated based on our designed experimental tests and DEM simulations. The approach of constructing the cohesion parameters at different scales can be extended to characterize cohesion effects in more complex wet polydisperse granular flows and describe their associated rheological behaviors.

低饱和度含液颗粒材料在自然环境和工业环境中都很常见，其中的间隙液体对颗粒的运动有很大影响，而颗粒尺寸的多分散性在决定系统内聚力水平方面起着至关重要的作用。在本研究中，基于所开发的离散元素模型，对湿式多分散颗粒柱的坍塌进行了数值研究，并进行了相应的溃坝实验，以验证我们的数值模型和方法。主要研究了动力学和流动流动性对颗粒粒度分布的依赖性，并通过分析颗粒路径长度和平均保真度探讨了基本机制。在利用混合理论提出的有效邦德数的基础上，通过考虑塌缩对系统尺寸效应的依赖性，定义了材料尺度上的宏观内聚力参数。根据我们设计的实验测试和 DEM 模拟，进一步验证了该内聚力参数在描述不同湿多分散颗粒塌陷方面的相关性。构建不同尺度内聚力参数的方法可扩展用于描述更复杂的湿式多分散粒料流中的内聚力效应，并描述其相关的流变行为。

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引用次数: 0

Numerical analyses of spherical indenter intrusion into sandstone: From laboratory tests to numerical simulations 球形压头侵入砂岩的数值分析：从实验室测试到数值模拟

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-22 DOI: 10.1016/j.compgeo.2024.106847

Sheng Zhang , Alfonso Rodriguez-Dono , Fei Song , Zilong Zhou

To explore the mechanical mechanisms of rock fracturing under compression during ball milling. The study investigates the effects of intrusion depth and indenter diameter on the evolution of stresses and plastic strains, integrating laboratory tests and numerical predictions. The results reveal a reduction in both axial and radial stresses with increasing intrusion depth into the rock. Shear stress experiences an initial rise followed by a decline, while circumferential stress demonstrates an initial increase followed by a rapid decrease in the radial direction. As the intrusion deepens, the predominant influence on plastic strain of rock shifts from shear stress dominance to a combined dominance of shear and circumferential stresses. The influence of the indenter diameter on the stress field diminishes following an exponential decay pattern. In terms of the plastic strain field, smaller indenters are more likely to induce plastic failure due to shear and circumferential stresses, larger indenters are more prone to plastic failure induced solely by shear stresses. As the number of indenters increases, the integration of the stress and plastic strain fields is enhanced. This implies that introducing more spherical indenters amplifies the collaborative effect, leading to a more cohesive fracturing of the rock.

探索球磨过程中岩石受压破裂的力学机制。研究结合实验室试验和数值预测，探讨了侵入深度和压头直径对应力和塑性应变演变的影响。结果表明，随着侵入岩石深度的增加，轴向和径向应力都会减小。剪应力最初上升，随后下降，而圆周应力最初上升，随后径向应力迅速下降。随着侵入的加深，对岩石塑性应变的主要影响从剪应力为主转变为剪应力和周向应力共同为主。压头直径对应力场的影响按照指数衰减模式逐渐减小。就塑性应变场而言，较小的压头更容易在剪应力和周向应力的作用下引起塑性破坏，而较大的压头则更容易仅在剪应力的作用下引起塑性破坏。随着压头数量的增加，应力场和塑性应变场的整合也会增强。这意味着引入更多的球形压痕会放大协同效应，从而导致岩石更有内聚力的断裂。

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引用次数: 0

A viscoplastic Cosserat peridynamics and the simulation of creep failure of geomaterials 粘塑性 Cosserat 周流体力学与土工材料蠕变破坏模拟

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-22 DOI: 10.1016/j.compgeo.2024.106831

Xianyang Guo, Ji Wan, Xihua Chu

In this study, within the framework of Cosserat peridynamics, the viscoplastic Perzyna’s model and the modified Drucker-Prager criterion are introduced to investigate the creep failure of geomaterials. The biaxial compressive creep for soft rock and the uniaxial creep for sandstone with a prefabricated flaw are designed to verify the proposed model. The effects of lateral pressure, internal friction angle, and cohesion on creep failure are investigated. Results show that the three stages of creep and the corresponding damage patterns are successfully predicted, which accords with the observations of numerical and experimental results. The larger lateral pressure makes it harder for geomaterials to creep. Geomaterials with a larger internal friction angle or cohesion have stronger shear resistance and less plastic deformation, making them less susceptible to creep failure. Besides, the Cosserat internal length l_c affects the inclination angles of the shear band.

本研究在 Cosserat 周流体力学框架内，引入了粘塑性 Perzyna 模型和修正的 Drucker-Prager 准则来研究土工材料的蠕变破坏。设计了软岩的双轴压缩蠕变和带有预制缺陷的砂岩的单轴蠕变来验证所提出的模型。研究了横向压力、内摩擦角和内聚力对蠕变破坏的影响。结果表明，成功地预测了蠕变的三个阶段和相应的破坏模式，这与数值和实验结果的观测结果一致。较大的侧压力会增加土工材料的蠕变难度。内摩擦角或内聚力较大的土工材料抗剪能力较强，塑性变形较小，不易发生蠕变破坏。此外，Cosserat 内长 lc 会影响剪切带的倾角。

引用次数: 0

Study on the micro-mechanical behavior and pore structure evolution mechanism of coral reef limestone based on digital rock core 基于数字岩芯的珊瑚礁灰岩微观力学行为及孔隙结构演化机制研究

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-22 DOI: 10.1016/j.compgeo.2024.106845

Xinping Li , Yingwei Zhu , Liangjun Wang , Dengxing Qu , Yi Luo , Fei Meng , Chenhao Pei , Wenhao Li

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.

珊瑚礁石灰岩（CRL）是一种海洋碳酸盐岩，具有高度发达的孔隙结构。孔隙结构对珊瑚礁灰岩的力学行为和破坏断裂过程有相当大的影响。为了研究 CRL 的微观力学行为及其孔隙结构演化机理，本文基于 CT 扫描获得的 CRL 数字岩芯模型。采用数字岩芯-有限元模型双向变换的方法，模拟分析了多孔 CRL 在准静压荷载作用下的微元物理力学行为。通过微观物理力学实验获得了 CRL 骨架的力学参数，并确定了骨架基体的 HJC 模型参数。这揭示了 CRL 在孔隙结构影响下的复杂断裂机制。研究表明，CRL 骨架主要由文石组成，平均弹性模量为 76.97 GPa。通过纳米压痕模拟验证了 HJC 固有模型及其参数的适用性。CRL 的破坏过程以复杂的应力集中、应力再分布和孔隙诱导断裂为特征。断裂扩展的演化主要受孔隙闭合、颗粒破碎和重新排列、微裂缝引发和扩展等过程的影响。孔隙度的演变主要受相同因素的影响，以及微裂缝的形成和现有裂缝的扩展。孔隙结构的不均匀性导致了损伤断裂中明显的各向异性和不均匀性。

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引用次数: 0

Numerical model for sediment transportation under breaking wave: The application exploration of VOF-CFD-DEM model in gas-fluid-particle system 破浪作用下的泥沙输运数值模型：VOF-CFD-DEM 模型在气-流-粒子系统中的应用探索

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-22 DOI: 10.1016/j.compgeo.2024.106844

Boen Li, Huihuan Ma

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

k - ω

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.

计算流体动力学-离散元法（CFD-DEM）模型与流体体积法（VOF）相结合，用于研究复杂的气-流-粒子耦合系统。为了提高模型的可行性，在模型中采用了提高效率和精度的方法，包括粗粒度法、多孔介质替代法和半解析法。为了验证模型的有效性和准确性，对颗粒入水和溃坝情景进行了模拟，随后利用 VOF-CFD-DEM 模型研究了溃坝波浪下的泥沙输运。对各种湍流模型进行比较后发现，稳定 k-ω 模型能够以可接受的效率和精度模拟破浪。该研究探讨了流动特性、作用于斜坡的力以及典型的泥沙运动，提供了与气-流-粒子系统相关的详细案例研究和数据。这项工作将 VOF-CFD-DEM 模型的应用扩展到了海洋工程的极端条件，为复杂的工程挑战提供了中观视角。

{"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}

引用次数: 0

Numerical prediction of frost heave in soils: The role of the ice lens initiation criterion 土壤冻浪的数值预测：冰透镜启动标准的作用

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-21 DOI: 10.1016/j.compgeo.2024.106833

Jinfeng Li , Zili Wang , Jidong Teng , Sheng Zhang

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.

冰透镜起始标准是一项关键的力学性能，对于研究冻浪中水与热传输机制之间的相互作用至关重要。由于冰透镜成冰现象的复杂性，冰透镜成冰标准因不同的理论模型而异，难以统一评价。为了研究冰形成标准的复杂物理机制，提出了一个统一的理论模型来模拟四种常用标准（中性应力标准、解冻水膜标准、孔隙冰压力标准和经验含水量标准）的冰形成过程。通过研究四种不同土壤性质下的冻胀、冰透镜分布和冻胀率，研究了不同评估的物理机制。研究结果表明，中性应力标准比目前行之有效的冰透镜形成标准更准确、更稳定。此外，研究还揭示了孔隙冰压力与未冻结水膜之间的显著相似性。由于缺乏可靠的物理基础，经验含水量容易出现重大误差。

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引用次数: 0

Indirect models for SWCC parameters: reducing prediction uncertainty with machine learning 全球降水潜能值参数的间接模型：利用机器学习减少预测的不确定性

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-19 DOI: 10.1016/j.compgeo.2024.106823

Xuzhen He , Guoqing Cai , Daichao Sheng

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.

土壤水特征曲线（SWCC）对于模拟水和有害物质在地下渗流带的迁移至关重要。然而，测量 SWCC 通常既麻烦又耗时。本文介绍了一些间接模型，这些模型利用粒径分布和孔隙度等易于测量的数量，以概率分布的方式预测 SWCC 参数。本文首先建立了一个联合正态模型，并将由此推导出的条件概率作为预测模型。然而，该模型的预测不确定性极高。为了降低这种不确定性，我们探索了各种机器学习技术，包括引入变化尺度对预测因子的依赖性、使用人工神经网络（ANN）对非线性依赖性进行建模、加入额外的预测特征以及生成更大的数据集。最终的机器学习模型成功地降低了预测的不确定性，并在一组单独的样本上进行了严格测试，以防止过度拟合。

引用次数: 0

What defines a “site” in geotechnical engineering?: A comparative study between local and global big indirect databases 如何定义岩土工程中的 "场地"？地方和全球大间接数据库的比较研究

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-19 DOI: 10.1016/j.compgeo.2024.106826

Taiga Saito , Yu Otake , Stephen Wu , Daiki Takano , Yuri Sugiyama , Ikumasa Yoshida

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.

岩土工程一直面临着从有限的土壤数据中准确评估各种物理特性的挑战。为了利用数据驱动方法解决这一问题，本研究在对东京海底粘土进行广泛采样的基础上，引入了创新的本地大间接数据库（Local-BID），并将其与汇集了众多国际站点数据的综合性全球大间接数据库（Global-BID）进行了比较。比较结果表明，Local-BID 和 Global-BID 的数据变异性几乎相同，从而突出了岩土工程中 "场地 "的定义和参数变异性概念等基本问题。通过细致的分析，我们探讨了数据库选择、观测点数量和估算指标对分层贝叶斯估算结果的影响。有趣的是，虽然在不同条件下，我们估算结果的中值保持稳定，但方差却受到这些因素的强烈影响。此外，我们对分层贝叶斯模型中使用的 "站点 "定义进行了严格的重新评估，该定义通常根据站点的平面距离进行分组，而不考虑垂直分层。尽管这一定义可以发挥基本作用，但我们的研究结果表明，结合地层分类来定义子站点可以加强站点特征评估，并通过对土壤成分变化的详细分析来帮助理解站点的相似性。

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引用次数: 0

Molecular dynamics simulations of the creep behavior of illite in the net-like red soils of Xuancheng, China 中国宣城网状红壤中伊利石蠕变行为的分子动力学模拟

IF 5.3 1区工程技术 Q1 COMPUTER SCIENCE, INTERDISCIPLINARY APPLICATIONS

Computers and Geotechnics

Pub Date : 2024-10-19 DOI: 10.1016/j.compgeo.2024.106840

Mingwu Wang, Yuhan Zhang, Jiahui Yan, Feng Xiong

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.

网状红土的蠕变行为主要取决于粘土矿物原子在纳米尺度上的微观力学行为。利用 XRD 和 SEM-EDS 实验确定的伊利石 1M-tv 构型，采用传统的分子动力学（MD）模拟方法探讨了不同加载方向的力学性能。此外，还提出了一种基于过渡态理论的新型 MD 模拟方法来讨论温度效应。模拟结果表明，与横向相比，垂直于伊利石层的拉伸极限应力值最小，面内剪切比横向剪切有更大的阻力。伊利石的抗拉、抗压和抗剪强度随温度升高而降低，而在相同加载时间下的稳态蠕变应变则随温度升高而增加。进入加速蠕变破坏阶段的能量障碍约为 18 kcal/mol。此外，改进的 MD 模拟方法可以将时间尺度从 200 ps 延长到 186 天。这些结果可以得出结论：所提出的 MD 模拟方法可以为研究粘土矿物在纳米尺度实验相关时间尺度上的蠕变行为提供有力的工具。

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引用次数: 0