Shengjie Rui, Lizhong Wang, Zefeng Zhou, H. Jostad, Zhen Guo
To provide a more reliable shared anchor for floating wind farms, a novel caisson-plate gravity anchor (CGA) is proposed. This design merges the benefits of both gravity anchors and suction caissons. Centrifuge model tests adopting only half of each anchor were carried out to study their bearing performance in sand. Additionally, particle image velocimetry (PIV) analyses were performed to monitor anchor movement and soil displacement. As supplementary data, numerical simulations with an advanced hypoplasticity model were also conducted to reveal the anchor capacity mobilisation mechanism. Findings indicate that the novel CGA possesses a significantly higher bearing capacity compared to standalone caisson or plate designs. By adding a plate above the caisson and increasing its weight, the anchor failure modes may shift from forward rotation to translational movement. Additionally, this adjustment may transition the brittle failure to a more reliable ductile failure. This augmented capacity of the CGA stems from the expanded soil mobilisation region and increased soil stress level in front of the caisson. The proposed CGA provides a promising solution for shared anchors in floating wind farms.
{"title":"Bearing performance of a novel caisson-plate gravity anchor","authors":"Shengjie Rui, Lizhong Wang, Zefeng Zhou, H. Jostad, Zhen Guo","doi":"10.1680/jgeot.23.00451","DOIUrl":"https://doi.org/10.1680/jgeot.23.00451","url":null,"abstract":"To provide a more reliable shared anchor for floating wind farms, a novel caisson-plate gravity anchor (CGA) is proposed. This design merges the benefits of both gravity anchors and suction caissons. Centrifuge model tests adopting only half of each anchor were carried out to study their bearing performance in sand. Additionally, particle image velocimetry (PIV) analyses were performed to monitor anchor movement and soil displacement. As supplementary data, numerical simulations with an advanced hypoplasticity model were also conducted to reveal the anchor capacity mobilisation mechanism. Findings indicate that the novel CGA possesses a significantly higher bearing capacity compared to standalone caisson or plate designs. By adding a plate above the caisson and increasing its weight, the anchor failure modes may shift from forward rotation to translational movement. Additionally, this adjustment may transition the brittle failure to a more reliable ductile failure. This augmented capacity of the CGA stems from the expanded soil mobilisation region and increased soil stress level in front of the caisson. The proposed CGA provides a promising solution for shared anchors in floating wind farms.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141360964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Suffusion can be defined as the loss of relatively small soil particles in gap-graded soils without any volume change. This study investigates the susceptibility of interaction energy-induced suffusion in sand-clay mixtures through laboratory-scale two-dimensional flow cell. The filtrated clay during the injection was measured at three outlets to assess the gravity and reattachment effects as a function of clay type (kaolinite, illite, and bentonite) and sand grain size. It was found that the settling of detached clay particles and the reattachment effect during their transport through the sand medium is a strong function of the swelling potential of clay and the size ratio between sand and clay. In addition, observed particle size distributions of clay at the outlet demonstrated that the relatively small and large clay particles are susceptible to suffusion for non-swelling and swelling clay respectively. The comparison of total filtrated clay between two-dimensional flow cell and the typical soil-column experiments (one-dimensional flow) revealed a high chance of underestimating suffusion using soil-column experiments to assess the suffusion of sand-clay mixtures.
{"title":"Two-dimensional experimental assessment of interaction energy-induced suffusion in sand-clay mixtures","authors":"Jongmuk Won, Incheol Joo","doi":"10.1680/jgeot.23.00265","DOIUrl":"https://doi.org/10.1680/jgeot.23.00265","url":null,"abstract":"Suffusion can be defined as the loss of relatively small soil particles in gap-graded soils without any volume change. This study investigates the susceptibility of interaction energy-induced suffusion in sand-clay mixtures through laboratory-scale two-dimensional flow cell. The filtrated clay during the injection was measured at three outlets to assess the gravity and reattachment effects as a function of clay type (kaolinite, illite, and bentonite) and sand grain size. It was found that the settling of detached clay particles and the reattachment effect during their transport through the sand medium is a strong function of the swelling potential of clay and the size ratio between sand and clay. In addition, observed particle size distributions of clay at the outlet demonstrated that the relatively small and large clay particles are susceptible to suffusion for non-swelling and swelling clay respectively. The comparison of total filtrated clay between two-dimensional flow cell and the typical soil-column experiments (one-dimensional flow) revealed a high chance of underestimating suffusion using soil-column experiments to assess the suffusion of sand-clay mixtures.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141361969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Merita Tafili, Patrick Staubach, Jan Machaček, Hauke Zachert, Torsten Wichtmann
A critical investigation of three constitutive models for clay by means of analyses of a sophisticated laboratory testing program and of centrifuge tests on monopiles in clay subjected to (cyclic) lateral loading is presented. Constitutive models of varying complexity, namely the basic Modified Cam Clay model, the hypoplastic model with Intergranular Strain (known as Clay hypoplasticity model) and the more recently proposed anisotropic visco-ISA model, are considered. From the simulations of the centrifuge tests with monotonic loading it is concluded that all three constitutive models give satisfactory results if a proper calibration of constitutive model parameters and proper initialisation of state variables is ensured. In the case of cyclic loading, the AVISA model is found to perform superior to the hypoplastic model with Intergranular Strain.
{"title":"Predictive abilities of constitutive models for clay under monotonic and cyclic loading: element tests and centrifuge experiments","authors":"Merita Tafili, Patrick Staubach, Jan Machaček, Hauke Zachert, Torsten Wichtmann","doi":"10.1680/jgeot.23.00268","DOIUrl":"https://doi.org/10.1680/jgeot.23.00268","url":null,"abstract":"A critical investigation of three constitutive models for clay by means of analyses of a sophisticated laboratory testing program and of centrifuge tests on monopiles in clay subjected to (cyclic) lateral loading is presented. Constitutive models of varying complexity, namely the basic Modified Cam Clay model, the hypoplastic model with Intergranular Strain (known as Clay hypoplasticity model) and the more recently proposed anisotropic visco-ISA model, are considered. From the simulations of the centrifuge tests with monotonic loading it is concluded that all three constitutive models give satisfactory results if a proper calibration of constitutive model parameters and proper initialisation of state variables is ensured. In the case of cyclic loading, the AVISA model is found to perform superior to the hypoplastic model with Intergranular Strain.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140967594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This paper presents a new formulation of the problem of tunnelling effects on pipelines, which incorporates the tunnel kinematic constraints in the tunnel-soil-pipeline interaction analysis. This ‘constrained continuum formulation’ can be considered an extension of the original ‘two-stage’ elastic-continuum method, which traditionally neglects the mutual influence of the pipeline on the tunnel and vice versa. The new approach retains the advantage of using the greenfield condition as an input, but it allows closed-form consideration of the stiffening effect of the tunnel on the soil domain. The paper details the formulation and, then, provides an investigation into the effect of varying fixities: namely, both as ‘wished-in-place’ tunnels and as evolving, advancing constraints, with the tunnel “construction”. Normalised solutions are presented and compared with the previous formulation. In general, the addition of tunnel constraints leads to a stiffer soil action and, thus, higher bending stressing in the pipeline: modelling of the tunnel kinematic constraint is conservative. The question of when such analysis is desired is discussed, concluding with a simple-to-use inequality suitable for design.
{"title":"Introducing tunnel kinematic constraints into an elastic continuum formulation of tunnel-soil-pipeline interaction","authors":"A. Klar, A. Franza, M. Zhou, H. W. Huang","doi":"10.1680/jgeot.24.00023","DOIUrl":"https://doi.org/10.1680/jgeot.24.00023","url":null,"abstract":"This paper presents a new formulation of the problem of tunnelling effects on pipelines, which incorporates the tunnel kinematic constraints in the tunnel-soil-pipeline interaction analysis. This ‘constrained continuum formulation’ can be considered an extension of the original ‘two-stage’ elastic-continuum method, which traditionally neglects the mutual influence of the pipeline on the tunnel and vice versa. The new approach retains the advantage of using the greenfield condition as an input, but it allows closed-form consideration of the stiffening effect of the tunnel on the soil domain. The paper details the formulation and, then, provides an investigation into the effect of varying fixities: namely, both as ‘wished-in-place’ tunnels and as evolving, advancing constraints, with the tunnel “construction”. Normalised solutions are presented and compared with the previous formulation. In general, the addition of tunnel constraints leads to a stiffer soil action and, thus, higher bending stressing in the pipeline: modelling of the tunnel kinematic constraint is conservative. The question of when such analysis is desired is discussed, concluding with a simple-to-use inequality suitable for design.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140966624","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recycling cement-amended tailings into subsurface cavities has delivered competitive socioeconomic revenue for underground mining. However, recent instances of anomalous thermal pressure in consolidating backfill have raised growing concerns over the current design philosophy. This study demonstrates that the excellent hydraulic sealing and considerable chemical energy inherent in cemented backfill can spontaneously generate substantial thermal pressurization through constrained pore-fluid expansion. An analytical solution is hence developed for characterizing the non-isothermal behaviour of hydrating backfill based on classical thermo-poroelasticity. The influence of preparation condition and mix design on the pressure evolution in time domain and during spontaneous heat generation is then thoroughly examined, successfully pinpointing the causal mechanism responsible for typical thermal pressure anomalies. It is demonstrated that the anomalous pressure is attributable to both the conservative binder usage, which increases the intrinsic heat load, and the elevated initial temperature, which promotes water volume expansion. The fundamental influence of temperature-sensitive water expansivity on the path dependence of thermal pressurization is also elucidated. This study thus contributes to a comprehensive understanding of the thermally correlated pressure anomalies that frequently occur in field operations. These critical findings would also hold practical implications for designing successful backfill solutions in challenging mine environments.
{"title":"Aquathermal effect of anomalous pressure generation in consolidating minefill","authors":"G. D. Lu, A. P. S. Selvadurai, M. Meguid","doi":"10.1680/jgeot.23.00410","DOIUrl":"https://doi.org/10.1680/jgeot.23.00410","url":null,"abstract":"Recycling cement-amended tailings into subsurface cavities has delivered competitive socioeconomic revenue for underground mining. However, recent instances of anomalous thermal pressure in consolidating backfill have raised growing concerns over the current design philosophy. This study demonstrates that the excellent hydraulic sealing and considerable chemical energy inherent in cemented backfill can spontaneously generate substantial thermal pressurization through constrained pore-fluid expansion. An analytical solution is hence developed for characterizing the non-isothermal behaviour of hydrating backfill based on classical thermo-poroelasticity. The influence of preparation condition and mix design on the pressure evolution in time domain and during spontaneous heat generation is then thoroughly examined, successfully pinpointing the causal mechanism responsible for typical thermal pressure anomalies. It is demonstrated that the anomalous pressure is attributable to both the conservative binder usage, which increases the intrinsic heat load, and the elevated initial temperature, which promotes water volume expansion. The fundamental influence of temperature-sensitive water expansivity on the path dependence of thermal pressurization is also elucidated. This study thus contributes to a comprehensive understanding of the thermally correlated pressure anomalies that frequently occur in field operations. These critical findings would also hold practical implications for designing successful backfill solutions in challenging mine environments.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140972095","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jian Hu, Yang Xiao, Jinquan Shi, A. Stuedlein, T. M. Evans
Incorporation of nonplastic fines can dramatically affect the liquefaction resistance and stiffness of sands. This study aims to evaluate the influence of nonplastic fines on the liquefaction resistance and small-strain shear modulus of calcareous sand under cyclic loading. Forty-seven sets of undrained cyclic triaxial tests and companion bender element tests are conducted on reconstituted specimens. The cyclic behavior of clean sand and silty sand with varying fines content is examined with respect to the global void ratio, relative density, and granular skeleton void ratio. The findings demonstrate that the microscopic contacts between coarse and fine grains have a significant impact on the macroscopic behavior of sand-fines mixtures. The experimental findings are evaluated using the equivalent granular skeleton void ratio, which has been recognized as a suitable parameter to describe the overall effect of fines. The findings on calcareous sand with fines are supplemented and compared with published data in accordance with the semiempirical simplified approach for liquefaction triggering based on shear wave velocity.
{"title":"Small-strain shear modulus and liquefaction resistance of calcareous sand with non-plastic fines","authors":"Jian Hu, Yang Xiao, Jinquan Shi, A. Stuedlein, T. M. Evans","doi":"10.1680/jgeot.23.00199","DOIUrl":"https://doi.org/10.1680/jgeot.23.00199","url":null,"abstract":"Incorporation of nonplastic fines can dramatically affect the liquefaction resistance and stiffness of sands. This study aims to evaluate the influence of nonplastic fines on the liquefaction resistance and small-strain shear modulus of calcareous sand under cyclic loading. Forty-seven sets of undrained cyclic triaxial tests and companion bender element tests are conducted on reconstituted specimens. The cyclic behavior of clean sand and silty sand with varying fines content is examined with respect to the global void ratio, relative density, and granular skeleton void ratio. The findings demonstrate that the microscopic contacts between coarse and fine grains have a significant impact on the macroscopic behavior of sand-fines mixtures. The experimental findings are evaluated using the equivalent granular skeleton void ratio, which has been recognized as a suitable parameter to describe the overall effect of fines. The findings on calcareous sand with fines are supplemented and compared with published data in accordance with the semiempirical simplified approach for liquefaction triggering based on shear wave velocity.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-05-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141002023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yang Li, M. Otsubo, Vasileios Angelidakis, R. Kuwano, S. Nadimi
This contribution provides high fidelity images of real granular materials with the aid of X-ray micro computed tomography (μCT), and employs a multi-sphere representation to reconstruct non-spherical particles. Through the discrete element method (DEM) simulations on granular samples composed of these non-spherical clumps, the effect of particle shape on the macroscopic mechanical response and microscopic soil fabric evolution is examined for soil assemblies under triaxial compression. Simulation results indicate that materials with more irregular particles tend to show higher shear resistance in both peak and critical states, while exhibiting higher void ratio under isotropic loading conditions and in the critical state. The proposed critical state parameters for describing the sensitivity of the mean coordination number to confining pressures are larger as particles become more irregular. At a microscopic level of observation, directional and scalar parameters of particle contacts are sensitive to predefined particle asperities. More irregular materials appear to exhibit higher fabric anisotropy regarding particle orientation in the critical state, while branch vector is affected by both contact modes and particle shape. The critical stress ratio from the simulation results is validated by comparing with experimental results, and further found to be linearly linked to the shape-weighted fabric anisotropy indices.
这篇论文借助 X 射线显微计算机断层扫描 (μCT)，提供了真实颗粒材料的高保真图像，并采用多球体表示法重建非球形颗粒。通过对由这些非球形团块组成的颗粒样本进行离散元法（DEM）模拟，研究了颗粒形状对三轴向压缩下土壤组合的宏观力学响应和微观土壤结构演变的影响。模拟结果表明，含有更多不规则颗粒的材料在峰值和临界状态下往往表现出更高的抗剪性，同时在各向同性加载条件下和临界状态下表现出更高的空隙率。随着颗粒变得越来越不规则，用于描述平均配位数对约束压力敏感性的临界状态参数也越来越大。在微观观察层面上，颗粒接触的方向和标量参数对预定义的颗粒尖角很敏感。在临界状态下，更不规则的材料似乎在颗粒方向上表现出更高的结构各向异性，而分支矢量则同时受到接触模式和颗粒形状的影响。模拟结果中的临界应力比通过与实验结果的比较得到了验证，并进一步发现它与形状加权织物各向异性指数呈线性关系。
{"title":"Exploring the micro-to-macro response of granular soils with real particle shapes via μCT-aided DEM analyses","authors":"Yang Li, M. Otsubo, Vasileios Angelidakis, R. Kuwano, S. Nadimi","doi":"10.1680/jgeot.23.00162","DOIUrl":"https://doi.org/10.1680/jgeot.23.00162","url":null,"abstract":"This contribution provides high fidelity images of real granular materials with the aid of X-ray micro computed tomography (μCT), and employs a multi-sphere representation to reconstruct non-spherical particles. Through the discrete element method (DEM) simulations on granular samples composed of these non-spherical clumps, the effect of particle shape on the macroscopic mechanical response and microscopic soil fabric evolution is examined for soil assemblies under triaxial compression. Simulation results indicate that materials with more irregular particles tend to show higher shear resistance in both peak and critical states, while exhibiting higher void ratio under isotropic loading conditions and in the critical state. The proposed critical state parameters for describing the sensitivity of the mean coordination number to confining pressures are larger as particles become more irregular. At a microscopic level of observation, directional and scalar parameters of particle contacts are sensitive to predefined particle asperities. More irregular materials appear to exhibit higher fabric anisotropy regarding particle orientation in the critical state, while branch vector is affected by both contact modes and particle shape. The critical stress ratio from the simulation results is validated by comparing with experimental results, and further found to be linearly linked to the shape-weighted fabric anisotropy indices.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140358932","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Qian Hu, Fei Han, M. Prezzi, R. Salgado, Minghua Zhao, H. Wang, B. M. Lehane, M. F. Bransby, A. Askarinejad, L. Z. Wang
{"title":"Discussion on lateral load response of large-diameter monopiles in sand","authors":"Qian Hu, Fei Han, M. Prezzi, R. Salgado, Minghua Zhao, H. Wang, B. M. Lehane, M. F. Bransby, A. Askarinejad, L. Z. Wang","doi":"10.1680/jgeot.24.00990","DOIUrl":"https://doi.org/10.1680/jgeot.24.00990","url":null,"abstract":"","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140381764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanhao Zheng, B. Baudet, Pierre Delage, Jean-Michel Pereira, P. Sammonds, Prithvendra Singh, D. N. Singh
{"title":"Discussion on ‘Pore changes in an illitic clay during one-dimensional compression’","authors":"Yanhao Zheng, B. Baudet, Pierre Delage, Jean-Michel Pereira, P. Sammonds, Prithvendra Singh, D. N. Singh","doi":"10.1680/jgeot.24.00991","DOIUrl":"https://doi.org/10.1680/jgeot.24.00991","url":null,"abstract":"","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140427269","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiangtao Lei, Marcos Arroyo, M. Ciantia, Ningning Zhang
Creep of granular soils is frequently accompanied by grain breakage. Stress corrosion driven grain breakage offers a micromechanically based explanation for granular creep. This study incorporates that concept into a new model based on the discrete element method (DEM) to simulate creep in sands. The model aims for conceptual simplicity, computational efficiency and ease of calibration. To this end a new form of normalized Charles power law is incorporated into a DEM model for rough-crushable sands based on the particle splitting technique. The model is implemented using a controlled on-off computational strategy. The model is validated by simulating creep in quartz sands in oedometric and triaxial conditions. Model predictions are shown to compare favourably with experimental results in terms of creep strain, creep strain rates and particle breakage. The model proposed would facilitate the calibration of phenomenological continuum models, but may be also useful to directly investigate structural scale phenomena, such as pile ageing.
粒状土的蠕变经常伴随着晶粒破裂。应力腐蚀驱动的晶粒破碎为粒状蠕变提供了一种基于微观力学的解释。本研究将这一概念纳入一个基于离散元素法（DEM）的新模型，以模拟砂土的蠕变。该模型力求概念简单、计算效率高且易于校准。为此，基于颗粒分裂技术，将归一化查尔斯幂律的一种新形式纳入了粗糙可挤压砂的 DEM 模型中。该模型采用受控开-关计算策略实现。通过模拟石英砂在气动和三轴条件下的蠕变，对模型进行了验证。结果表明，在蠕变应变、蠕变应变率和颗粒断裂方面，模型预测结果与实验结果相比毫不逊色。提出的模型将有助于校准现象连续模型，但也可能有助于直接研究结构尺度现象，如桩老化。
{"title":"A fracture-based discrete model for simulating creep in quartz sands","authors":"Jiangtao Lei, Marcos Arroyo, M. Ciantia, Ningning Zhang","doi":"10.1680/jgeot.23.00068","DOIUrl":"https://doi.org/10.1680/jgeot.23.00068","url":null,"abstract":"Creep of granular soils is frequently accompanied by grain breakage. Stress corrosion driven grain breakage offers a micromechanically based explanation for granular creep. This study incorporates that concept into a new model based on the discrete element method (DEM) to simulate creep in sands. The model aims for conceptual simplicity, computational efficiency and ease of calibration. To this end a new form of normalized Charles power law is incorporated into a DEM model for rough-crushable sands based on the particle splitting technique. The model is implemented using a controlled on-off computational strategy. The model is validated by simulating creep in quartz sands in oedometric and triaxial conditions. Model predictions are shown to compare favourably with experimental results in terms of creep strain, creep strain rates and particle breakage. The model proposed would facilitate the calibration of phenomenological continuum models, but may be also useful to directly investigate structural scale phenomena, such as pile ageing.","PeriodicalId":508398,"journal":{"name":"Géotechnique","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139960513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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