Computers and Geotechnics最新文献_第7页

Probabilistic evaluation of landslide influence zones considering stratigraphic dips and nonstationarity of soil properties 考虑地层倾角和土壤特性的非稳定性，对滑坡影响区进行概率评估

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

Computers and Geotechnics

Pub Date : 2024-10-18 DOI: 10.1016/j.compgeo.2024.106815

Jian-Ping Li , Shui-Hua Jiang , Guo-Tao Ma , Mohammad Rezania , Mohaddeseh Mousavi Nezhad , Jian-Hong Wan

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.

准确预测滑坡运动对有效防控灾害至关重要。然而，目前有关滑坡大变形概率分析的研究都假定土壤具有横向各向异性，忽视了土壤结构和沉积方向对滑坡后行为的影响。虽然人们经常分析地层倾角和非稳态土壤取向对斜坡稳定性的具体影响，但这些影响对斜坡崩塌后行为的影响尚未得到深入探讨。本研究提出了一种新的概率框架，用于模拟山体滑坡和量化危险区，其中包含复杂的地层倾角和两种典型的非稳态土壤走向。新方法将非稳态随机场（RF）理论与空间自相关结构旋转相结合。考虑到不同的地层倾角和非稳态方向，该方法得出了计算不同位置土层厚度和深度的公式。这种方法可以模拟具有垂直和地层非稳态的垫层和反向土壤的参数分布。然后使用广义插值材料点法（GIMP）模拟斜坡的破坏后行为。研究结果表明，忽略土壤参数的空间变化会导致低估滑坡影响区。此外，土质参数和地层倾角的非稳态特征也会影响斜坡的破坏机制以及滑出和影响距离的超限概率。所提出的方法提高了滑出和影响距离预测的准确性，可作为一种新的有价值的灾害管理和减灾工具。

{"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}

引用次数: 0

Incipient particle motion in the expansion of water-inrush channel by considering the 3D relative exposure degree 考虑三维相对暴露程度的水流通道扩张过程中的初始颗粒运动

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

Computers and Geotechnics

Pub Date : 2024-10-18 DOI: 10.1016/j.compgeo.2024.106842

J. Wu, G.H. Dai, L.W. Zhang, L. Guo, H. Deng

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.

涌水是富水隧道施工中的高风险灾害。颗粒在涌水通道侧壁的损失是关键因素。考虑三维相对暴露程度，研究涌水通道膨胀过程中的初生颗粒运动，对涌水通道的初生流速进行分析。利用 BP 神经网络和三轴试验获得中观参数。通过 DEM-CFD 耦合，对初生颗粒运动进行了数值模拟。分析了三维相对暴露程度对初生流速度的影响。最后，通过实验室试验和工程现场试验验证了水流涌道扩张过程中的初生流速。结果表明(1）大颗粒的初生流速更大；（2）倾角大的颗粒更容易移动；（3）颗粒的三维相对暴露度符合威布尔分布和指数分布；（4）颗粒的初生流速更接近滚动不稳定的临界流速；（5）初生流速由膨胀槽底部的颗粒决定。

{"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}

引用次数: 0

Thermal effect on long-term behaviors of rocks: A DEM study 岩石长期行为的热效应：DEM 研究

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

Computers and Geotechnics

Pub Date : 2024-10-18 DOI: 10.1016/j.compgeo.2024.106839

Yuan Sun , Chung Yee Kwok , Kang Duan

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 (E) 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 E 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.

放射性废料会对核废料贮存库中的围岩产生长期加热，从而可能导致裂缝的持续增长。为确保核废料的安全隔离，必须研究长期加热对岩石机械性能和随时间变化的行为的影响。本研究基于离散元素法（DEM）提出了温度依赖性应力腐蚀（T-SC）模型，该模型通过晶粒膨胀和温度依赖性亚临界裂纹生长纳入了热效应。生成北山花岗岩试样，并通过单轴压缩和蠕变试验校准微参数。然后对试样进行不同温度（100-400 °C）的长期加热。结果表明，在短期和长期加热条件下，单轴压缩强度（UCS）和杨氏模量（E）呈现出增强-减弱的转变。增强的原因是晶粒膨胀导致微结构致密，而减弱的原因是裂纹数量增加。此外，从短期加热到长期加热，UCS 和 E 会随着亚临界裂纹的增长而减少。此外，失效时间缩短了 2-3 个数量级，对应力的敏感性降低，应力阈值随着温度的升高从 UCS 的 70% 显著降低到 44%。这些发现突出表明，当温度超过 200 °C时，长时间加热会对岩石产生明显的削弱作用。

{"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}

引用次数: 0

On the use of a unified constitutive model for modelling slope large deformations with material point method 论使用统一构成模型以材料点法模拟斜坡大变形

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

Computers and Geotechnics

Pub Date : 2024-10-18 DOI: 10.1016/j.compgeo.2024.106838

Bin Wang , Penglin Chen , Xia Li , Zixuan Zhang

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.

山体滑坡和泥石流会造成破坏性影响，尤其是当运动涉及从固态到液态的过渡过程时。弹塑性构造模型描述整个运动过程的能力有限；因此，本文在 GPU 加速的材料点法（MPM）框架内建立了一个统一的构造模型，其中包括低塑性模型和巴尼奥德模型。首先通过低速直接剪切试验验证了该模型，以证明其描述固态摩擦行为的能力，然后使用高速环形剪切试验检验了快速流动条件下的碰撞行为。统一模型对岩土工程大变形的有效性随后通过柱坍塌进行了验证，证明了统一模型在描述大变形过程方面优于传统构造模型。对整个柱体破坏过程中的动应力比这一指标进行了全面分析，发现动应力比与二阶功转换准则有很好的相关性，可以区分运动从固态向液态的过渡阶段。最后，将该构造模型应用于钱江坪和塔托帕尼滑坡的危害评估，进一步证明了该模型和 MPM 框架的适用性和稳定性。

{"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}

引用次数: 0

Load transfer model for vertically loaded non-circular piles 垂直加载非圆形桩的荷载传递模型

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

Computers and Geotechnics

Pub Date : 2024-10-18 DOI: 10.1016/j.compgeo.2024.106843

Hang Zhou , Yunzhou Li , Brian Sheil

The load-transfer (LT) method, involving a series of ‘t-z’ springs to represent pile shaft-soil interaction and a ‘q-z’ spring to represent pile tip-soil interaction, is widely used to model the load–displacement behaviour of vertically loaded piles. While a plethora of LT models have been proposed for piles with circular cross sections, they are not directly applicable to non-circular (NC) cross sections. Therefore, there is a lack of tailored solutions for rectangular, H-shaped and X-shaped piles even though they are common in geotechnical practice. The aim of this paper is to develop a general theoretical framework for the construction of LT curves for NC piles. This framework allows NC piles with any cross section to be considered. The LT curves for NC piles are formulated using a two-parameter hyperbolic model which requires input of (a) the initial elastic LT stiffness and (b) the unit ultimate shaft friction. The elastic stiffness for vertically loaded NC piles with arbitrary cross sections is described using a rigorous semi-analytical (SA) solution involving variational principles. A nonlinear numerical solution for the pile governing equation with the incorporated t-z and q-z curves is achieved using the Runge-Kutta (RK) method. The proposed LT curves are used to construct the pile governing equation and a numerical solution using the Runge-Kutta (RK) method is proposed to predict the responses of NC piles in drained sand. The proposed theoretical LT predictions of pile response are validated through comparisons to elastic–plastic finite element calculations.

荷载传递（LT）方法由一系列 "t-z "弹簧和 "q-z "弹簧组成，"t-z "弹簧表示桩轴与土的相互作用，"q-z "弹簧表示桩尖与土的相互作用，该方法被广泛用于模拟垂直荷载桩的荷载-位移行为。虽然针对圆形横截面的桩提出了大量 LT 模型，但这些模型并不能直接适用于非圆形（NC）横截面。因此，尽管矩形、H 形和 X 形桩在岩土工程实践中很常见，但仍缺乏针对它们的定制解决方案。本文旨在为构建 NC 桩的 LT 曲线开发一个通用理论框架。该框架允许考虑任何截面的数控桩。数控桩的 LT 曲线采用双参数双曲线模型，需要输入 (a) 初始弹性 LT 刚度和 (b) 单位极限轴摩擦力。对于具有任意横截面的垂直加载数控桩的弹性刚度，采用的是涉及变异原理的严格半解析（SA）解法。使用 Runge-Kutta (RK) 方法实现了包含 t-z 和 q-z 曲线的桩控制方程的非线性数值解。利用所提出的 LT 曲线构建桩基控制方程，并采用 Runge-Kutta (RK) 方法提出数值解决方案，以预测排水砂中数控桩的响应。通过与弹塑性有限元计算进行比较，验证了所提出的桩响应 LT 理论预测值。

{"title":"Load transfer model for vertically loaded non-circular piles","authors":"Hang Zhou , Yunzhou Li , Brian Sheil","doi":"10.1016/j.compgeo.2024.106843","DOIUrl":"10.1016/j.compgeo.2024.106843","url":null,"abstract":"<div><div>The load-transfer (LT) method, involving a series of ‘<em>t</em>-<em>z</em>’ springs to represent pile shaft-soil interaction and a ‘<em>q</em>-<em>z</em>’ spring to represent pile tip-soil interaction, is widely used to model the load–displacement behaviour of vertically loaded piles. While a plethora of LT models have been proposed for piles with circular cross sections, they are not directly applicable to non-circular (NC) cross sections. Therefore, there is a lack of tailored solutions for rectangular, H-shaped and X-shaped piles even though they are common in geotechnical practice. The aim of this paper is to develop a general theoretical framework for the construction of LT curves for NC piles. This framework allows NC piles with any cross section to be considered. The LT curves for NC piles are formulated using a two-parameter hyperbolic model which requires input of (a) the initial elastic LT stiffness and (b) the unit ultimate shaft friction. The elastic stiffness for vertically loaded NC piles with arbitrary cross sections is described using a rigorous semi-analytical (SA) solution involving variational principles. A nonlinear numerical solution for the pile governing equation with the incorporated <em>t-z</em> and <em>q-z</em> curves is achieved using the Runge-Kutta (RK) method. The proposed LT curves are used to construct the pile governing equation and a numerical solution using the Runge-Kutta (RK) method is proposed to predict the responses of NC piles in drained sand. The proposed theoretical LT predictions of pile response are validated through comparisons to elastic–plastic finite element calculations.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106843"},"PeriodicalIF":5.3,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142536990","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

Finite element analysis of large deformation for progressive failure of soil based on Cosserat continuum theory 基于 Cosserat 连续体理论的土壤渐进破坏大变形有限元分析

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

Computers and Geotechnics

Pub Date : 2024-10-17 DOI: 10.1016/j.compgeo.2024.106836

Hongxiang Tang , Binbin Xu , Wencheng Wei , Letian Liu , Fabing Sun

The large deformation accompanied by strain softening and strain localization of the material is usually encountered in geotechnical engineering. Integrating the RITSS method and the Cosserat continuum theory, a large deformation Cosserat-RITSS finite element method is developed to tackle this issue. Based on the second development interfaces of UEL and SDVINI offered by the finite element software ABAQUS, the Cosserat-RITSS method adopting the MUEM interpolation and mapping method is realized automatically and used to simulate the problem of progressive failure and large deformation characterized by strain localization. The accuracy and effectiveness of the proposed method are verified by the comparison of the small deformation and the large deformation analysis of the penetration process of a rigid strip foundation. Further, the Cosserat-RITSS method is used to analyze the large deformation of a retaining wall resisting on the soil with non-associated plastic flow and strain-softening properties. Compared with the classical RITSS method, it is demonstrated that the proposed method has better performancy of simulating large deformation and overcoming the pathological mesh-dependent problem usually suffered in the classical FEA of large deformation accompanied by strain localization.

岩土工程中通常会遇到伴随材料应变软化和应变局部化的大变形。综合 RITSS 方法和 Cosserat 连续理论，开发了一种大变形 Cosserat-RITSS 有限元方法来解决这一问题。基于有限元软件 ABAQUS 提供的 UEL 和 SDVINI 二次开发接口，采用 MUEM 插值和映射方法自动实现了 Cosserat-RITSS 方法，用于模拟以应变局部化为特征的渐进破坏和大变形问题。通过对刚性带状地基贯入过程的小变形和大变形分析对比，验证了所提方法的准确性和有效性。此外，Cosserat-RITSS 方法还用于分析具有非相关塑性流动和应变软化特性的土体上挡土墙的大变形。结果表明，与传统的 RITSS 方法相比，所提出的方法在模拟大变形方面具有更好的性能，并克服了传统有限元分析中通常存在的大变形伴随应变局部化的病态网格依赖问题。

{"title":"Finite element analysis of large deformation for progressive failure of soil based on Cosserat continuum theory","authors":"Hongxiang Tang , Binbin Xu , Wencheng Wei , Letian Liu , Fabing Sun","doi":"10.1016/j.compgeo.2024.106836","DOIUrl":"10.1016/j.compgeo.2024.106836","url":null,"abstract":"<div><div>The large deformation accompanied by strain softening and strain localization of the material is usually encountered in geotechnical engineering. Integrating the RITSS method and the Cosserat continuum theory, a large deformation Cosserat-RITSS finite element method is developed to tackle this issue. Based on the second development interfaces of UEL and SDVINI offered by the finite element software ABAQUS, the Cosserat-RITSS method adopting the MUEM interpolation and mapping method is realized automatically and used to simulate the problem of progressive failure and large deformation characterized by strain localization. The accuracy and effectiveness of the proposed method are verified by the comparison of the small deformation and the large deformation analysis of the penetration process of a rigid strip foundation. Further, the Cosserat-RITSS method is used to analyze the large deformation of a retaining wall resisting on the soil with non-associated plastic flow and strain-softening properties. Compared with the classical RITSS method, it is demonstrated that the proposed method has better performancy of simulating large deformation and overcoming the pathological mesh-dependent problem usually suffered in the classical FEA of large deformation accompanied by strain localization.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106836"},"PeriodicalIF":5.3,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446993","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

The effects of temperature and indentation parameters on mechanical properties of calcite through molecular dynamics simulation 通过分子动力学模拟研究温度和压痕参数对方解石力学性能的影响

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

Computers and Geotechnics

Pub Date : 2024-10-16 DOI: 10.1016/j.compgeo.2024.106835

Bingqi Wang , Wendong Yang , Jun Yao , Yunfeng Zhang , Zhaoqin Huang

The extraction of deep energy resources often encounters high-temperature environments, making it challenging to drill cores and conduct conventional rock mechanics tests to explore the mechanical properties of reservoir rocks. Currently, the methods to study the effects of temperature on rock minerals are quite limited. Based on molecular dynamics and considering the effect of temperature on rock minerals properties, the analysis and simulation method for rock mechanical properties in indentation tests are proposed. This paper elucidates the influence of temperature on the mechanical behavior of calcite from three aspects: nanoindentation results, atomic displacement, and strain. Simulation results show that the differences between the load–displacement curves of distinct crystal planes decrease as temperature increases, suggesting that temperature weakens the anisotropy of calcite to a certain extent. The indentation modulus initially increases and then decreases as the temperature increases, and the elastic recovery rate calculated based on the indentation morphology also shows this trend, elucidating the relationship between the weakening effect of high temperature and the constraining effect of the specimen. Increasing the temperature not only increases the displacement of calcite but also strengthens plastic deformation. The direction and extent of internal deformation propagation at different crystal planes show variations with increasing temperature, and the indentation accumulation gradually presents an asymmetric distribution. Additionally, we investigated the nanoindentation process of calcite under different indentation parameters, revealing that changes in indentation depth and the indenter radius can reflect the different elastic responses of crystal planes. Higher loading velocities enhance the strength of calcite and induce less plastic deformation. This work contributes to a deeper understanding of the microscopic deformation mechanisms of deep rocks and provides theoretical guidance for conducting nanoindentation tests on deep rocks.

深层能源资源的开采经常会遇到高温环境，这给钻取岩心和进行常规岩石力学测试以探索储层岩石的力学特性带来了挑战。目前，研究温度对岩石矿物影响的方法非常有限。本文以分子动力学为基础，考虑温度对岩石矿物性质的影响，提出了压痕试验中岩石力学性质的分析和模拟方法。本文从纳米压痕结果、原子位移和应变三个方面阐明了温度对方解石力学行为的影响。模拟结果表明，不同晶面的载荷-位移曲线之间的差异随着温度的升高而减小，说明温度在一定程度上削弱了方解石的各向异性。压痕模量随温度升高先增大后减小，根据压痕形态计算的弹性恢复率也呈现出这种趋势，阐明了高温削弱效应与试样约束效应之间的关系。温度升高不仅会增加方解石的位移，还会加强塑性变形。不同晶面的内部变形传播方向和程度随温度升高而变化，压痕累积逐渐呈现不对称分布。此外，我们还研究了不同压痕参数下方解石的纳米压痕过程，发现压痕深度和压头半径的变化可以反映晶面的不同弹性响应。加载速度越大，方解石的强度越高，引起的塑性变形越小。这项研究有助于加深对深部岩石微观变形机制的理解，并为在深部岩石上进行纳米压痕试验提供理论指导。

{"title":"The effects of temperature and indentation parameters on mechanical properties of calcite through molecular dynamics simulation","authors":"Bingqi Wang , Wendong Yang , Jun Yao , Yunfeng Zhang , Zhaoqin Huang","doi":"10.1016/j.compgeo.2024.106835","DOIUrl":"10.1016/j.compgeo.2024.106835","url":null,"abstract":"<div><div>The extraction of deep energy resources often encounters high-temperature environments, making it challenging to drill cores and conduct conventional rock mechanics tests to explore the mechanical properties of reservoir rocks. Currently, the methods to study the effects of temperature on rock minerals are quite limited. Based on molecular dynamics and considering the effect of temperature on rock minerals properties, the analysis and simulation method for rock mechanical properties in indentation tests are proposed. This paper elucidates the influence of temperature on the mechanical behavior of calcite from three aspects: nanoindentation results, atomic displacement, and strain. Simulation results show that the differences between the load–displacement curves of distinct crystal planes decrease as temperature increases, suggesting that temperature weakens the anisotropy of calcite to a certain extent. The indentation modulus initially increases and then decreases as the temperature increases, and the elastic recovery rate calculated based on the indentation morphology also shows this trend, elucidating the relationship between the weakening effect of high temperature and the constraining effect of the specimen. Increasing the temperature not only increases the displacement of calcite but also strengthens plastic deformation. The direction and extent of internal deformation propagation at different crystal planes show variations with increasing temperature, and the indentation accumulation gradually presents an asymmetric distribution. Additionally, we investigated the nanoindentation process of calcite under different indentation parameters, revealing that changes in indentation depth and the indenter radius can reflect the different elastic responses of crystal planes. Higher loading velocities enhance the strength of calcite and induce less plastic deformation. This work contributes to a deeper understanding of the microscopic deformation mechanisms of deep rocks and provides theoretical guidance for conducting nanoindentation tests on deep rocks.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106835"},"PeriodicalIF":5.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142441200","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

Effects of excavation size, rate, orientation, and depth on the hydromechanical response of argillaceous rocks 挖掘规模、速度、方向和深度对假火山岩水力学响应的影响

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

Computers and Geotechnics

Pub Date : 2024-10-16 DOI: 10.1016/j.compgeo.2024.106834

Davood Yazdani Cherati , Jean Vaunat , Antonio Gens Solé , Minh Ngoc Vu , Gilles Armand

In this study, a sensitivity analysis is performed to investigate the effects of excavation size, rate, orientation, and depth on the hydromechanical response of Callovo-Oxfordian (COx) argillaceous rocks. The elasto-viscoplastic argillite model, which incorporates a non-local regularization technique, is employed. Initially, a series of drained biaxial tests are simulated to investigate the effects of the non-local approach on post-peak strain softening and the evolution of localized shear bands. Subsequently, the effects of excavation size are assessed by modeling excavations with different diameters. A novel scaling framework is proposed to assess size effects while using non-local techniques. Then, rate effects are analyzed by isolating the sources of delayed response in the rock, i.e., hydrodynamic lag, viscoplasticity, and creep. Additionally, different drifts parallel to the major and minor natural principal stresses are simulated to distinguish the impacts of material anisotropy and in-situ stress anisotropy on the host rock response. Finally, the influence of the excavation depth is examined through simulating three drifts at different depths within the COx. The results reveal the efficiency of the proposed scaling approach in analyzing size effects. Furthermore, altering the excavation orientation and depth results in varied COx responses mainly due to changes in in-situ stress conditions.

本研究进行了一项敏感性分析，以研究开挖规模、速度、方向和深度对Callovo-Oxfordian（COx）千层岩水力学响应的影响。研究采用了包含非局部正则化技术的弹性-粘塑性假火山岩模型。首先，模拟了一系列排水双轴试验，以研究非局部方法对峰值后应变软化和局部剪切带演变的影响。随后，通过对不同直径的开挖进行建模，评估了开挖尺寸的影响。在使用非局部技术评估尺寸效应时，提出了一个新颖的比例框架。然后，通过分离岩石中延迟响应的来源，即流体动力滞后、粘塑性和蠕变，分析了速率效应。此外，还模拟了与主要和次要天然主应力平行的不同漂移，以区分材料各向异性和原位应力各向异性对主岩响应的影响。最后，通过模拟 COx 内不同深度的三个钻孔，研究了开挖深度的影响。结果表明，所提出的缩放方法在分析尺寸效应方面非常有效。此外，改变挖掘方向和深度会导致不同的 COx 反应，这主要是由于原位应力条件发生了变化。

{"title":"Effects of excavation size, rate, orientation, and depth on the hydromechanical response of argillaceous rocks","authors":"Davood Yazdani Cherati , Jean Vaunat , Antonio Gens Solé , Minh Ngoc Vu , Gilles Armand","doi":"10.1016/j.compgeo.2024.106834","DOIUrl":"10.1016/j.compgeo.2024.106834","url":null,"abstract":"<div><div>In this study, a sensitivity analysis is performed to investigate the effects of excavation size, rate, orientation, and depth on the hydromechanical response of Callovo-Oxfordian (COx) argillaceous rocks. The elasto-viscoplastic argillite model, which incorporates a non-local regularization technique, is employed. Initially, a series of drained biaxial tests are simulated to investigate the effects of the non-local approach on post-peak strain softening and the evolution of localized shear bands. Subsequently, the effects of excavation size are assessed by modeling excavations with different diameters. A novel scaling framework is proposed to assess size effects while using non-local techniques. Then, rate effects are analyzed by isolating the sources of delayed response in the rock, i.e., hydrodynamic lag, viscoplasticity, and creep. Additionally, different drifts parallel to the major and minor natural principal stresses are simulated to distinguish the impacts of material anisotropy and in-situ stress anisotropy on the host rock response. Finally, the influence of the excavation depth is examined through simulating three drifts at different depths within the COx. The results reveal the efficiency of the proposed scaling approach in analyzing size effects. Furthermore, altering the excavation orientation and depth results in varied COx responses mainly due to changes in in-situ stress conditions.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106834"},"PeriodicalIF":5.3,"publicationDate":"2024-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142446992","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}

引用次数: 0

Probabilistic Design Analysis of Plate Anchors in Spatially Variable Clay 空间可变粘土中板锚的概率设计分析

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

Computers and Geotechnics

Pub Date : 2024-10-15 DOI: 10.1016/j.compgeo.2024.106828

Pengpeng He , Gordon A. Fenton , D.V. Griffiths

Plate anchors play a vital role in various geotechnical structures, particularly in offshore settings where high pullout capacity is required. The current partial factor method accounts for uncertainties in loads and material properties separately using partial load and material factors, but it may not well address the effects of site investigation and soil spatial variability on the failure probability of design anchors. This study evaluated the reliability of offshore plate anchors designed using the partial factor method against the pullout limit state in clay. A Single-Random-Variable (SRV) method and a Random Finite Element Method (RFEM) were introduced and compared. Parametric studies were also performed to investigate the effects of load ratio, partial material factor, soil sampling location, and soil spatial correlation length on the estimated failure probability. The results highlight the importance of the soil sampling location and spatial variation in anchor design. The SRV method does not consider these factors, resulting in either over- or under-estimations of the failure probability compared to the RFEM. Practical implications from the findings were also discussed. Overall, this study aids in the probabilistic design of offshore plate anchors, the calibration of partial material factors, and in providing valuable guidance to their practical applications.

板锚在各种岩土结构中发挥着重要作用，尤其是在需要高抗拔能力的近海环境中。目前的部分系数法使用部分荷载和材料系数分别计算荷载和材料特性的不确定性，但可能无法很好地解决现场勘察和土壤空间变化对设计锚杆失效概率的影响。本研究针对粘土中的拉拔极限状态，评估了使用部分因子法设计的离岸板锚的可靠性。引入并比较了单随机变量法（SRV）和随机有限元法（RFEM）。还进行了参数研究，以探讨荷载比、部分材料系数、土壤取样位置和土壤空间相关长度对估计破坏概率的影响。结果凸显了土壤取样位置和空间变化在锚杆设计中的重要性。SRV 方法没有考虑这些因素，与 RFEM 相比，会导致失效概率估计过高或过低。还讨论了研究结果的实际意义。总之，这项研究有助于近海板锚的概率设计、部分材料因子的校准，并为其实际应用提供了宝贵的指导。

{"title":"Probabilistic Design Analysis of Plate Anchors in Spatially Variable Clay","authors":"Pengpeng He , Gordon A. Fenton , D.V. Griffiths","doi":"10.1016/j.compgeo.2024.106828","DOIUrl":"10.1016/j.compgeo.2024.106828","url":null,"abstract":"<div><div>Plate anchors play a vital role in various geotechnical structures, particularly in offshore settings where high pullout capacity is required. The current partial factor method accounts for uncertainties in loads and material properties separately using partial load and material factors, but it may not well address the effects of site investigation and soil spatial variability on the failure probability of design anchors. This study evaluated the reliability of offshore plate anchors designed using the partial factor method against the pullout limit state in clay. A Single-Random-Variable (SRV) method and a Random Finite Element Method (RFEM) were introduced and compared. Parametric studies were also performed to investigate the effects of load ratio, partial material factor, soil sampling location, and soil spatial correlation length on the estimated failure probability. The results highlight the importance of the soil sampling location and spatial variation in anchor design. The SRV method does not consider these factors, resulting in either over- or under-estimations of the failure probability compared to the RFEM. Practical implications from the findings were also discussed. Overall, this study aids in the probabilistic design of offshore plate anchors, the calibration of partial material factors, and in providing valuable guidance to their practical applications.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106828"},"PeriodicalIF":5.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433359","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

Multi-dimensional digital core simulation based research on heat transfer characteristics of multiphase fluids 基于多维数字岩心模拟的多相流体传热特性研究

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

Computers and Geotechnics

Pub Date : 2024-10-15 DOI: 10.1016/j.compgeo.2024.106822

Yanchi Liu , Baiquan Lin , Ting Liu , Jiahao He

The study of heat transfer in coal and rock masses is crucial for thermal storage engineering and geothermal utilization in abandoned mines. Nevertheless, previous research on heat transfer in this field has frequently neglected the interconnection between the flow and heat transfer of heat-working substances (HWS) within three-dimensional microcracks. To reveal the above mechanism, first, the multi-factor influence mechanism of coal and rock heat conduction was analyzed based on the gray system theory. Subsequently, meshes of the matrix and fractures were reconstructed using the digital core simulation technology based on scanning electron microscopy and computed tomography. Finally, a multi-dimensional and multi-scale coal conjugate heat transfer model was built. The results indicate that the heat flux of heat transfer in coal and rock in the heat inflow direction is 3.03–6.44 times as high as that in the direction perpendicular to the heat inflow direction. As the heat transfer of HWS continues, the influence of coal and rock composition diminishes, and the development degree of fractures becomes the major factor affecting heat transfer. Furthermore, alterations in phase state will result in modifications to the conjugated heat transfer mechanism. This study can provide guidance for HWS selection in abandoned mines.

煤块和岩块中的传热研究对于热储工程和废弃矿井的地热利用至关重要。然而，该领域以往的传热研究往往忽视了热工物质（HWS）在三维微裂隙内流动与传热之间的相互联系。为揭示上述机理，首先基于灰色系统理论分析了煤岩导热的多因素影响机理。随后，利用基于扫描电子显微镜和计算机断层扫描的数字岩心模拟技术重建了基质和裂缝的网格。最后，建立了多维度、多尺度的煤共轭传热模型。结果表明，煤和岩石在热流入方向的传热热通量是垂直于热流入方向的3.03-6.44倍。随着 HWS 传热的继续，煤和岩石成分的影响逐渐减小，裂缝的发育程度成为影响传热的主要因素。此外，相态的改变也会导致共轭传热机制的改变。这项研究可为废弃矿井的 HWS 选择提供指导。

{"title":"Multi-dimensional digital core simulation based research on heat transfer characteristics of multiphase fluids","authors":"Yanchi Liu , Baiquan Lin , Ting Liu , Jiahao He","doi":"10.1016/j.compgeo.2024.106822","DOIUrl":"10.1016/j.compgeo.2024.106822","url":null,"abstract":"<div><div>The study of heat transfer in coal and rock masses is crucial for thermal storage engineering and geothermal utilization in abandoned mines. Nevertheless, previous research on heat transfer in this field has frequently neglected the interconnection between the flow and heat transfer of heat-working substances (HWS) within three-dimensional microcracks. To reveal the above mechanism, first, the multi-factor influence mechanism of coal and rock heat conduction was analyzed based on the gray system theory. Subsequently, meshes of the matrix and fractures were reconstructed using the digital core simulation technology based on scanning electron microscopy and computed tomography. Finally, a multi-dimensional and multi-scale coal conjugate heat transfer model was built. The results indicate that the heat flux of heat transfer in coal and rock in the heat inflow direction is 3.03–6.44 times as high as that in the direction perpendicular to the heat inflow direction. As the heat transfer of HWS continues, the influence of coal and rock composition diminishes, and the development degree of fractures becomes the major factor affecting heat transfer. Furthermore, alterations in phase state will result in modifications to the conjugated heat transfer mechanism. This study can provide guidance for HWS selection in abandoned mines.</div></div>","PeriodicalId":55217,"journal":{"name":"Computers and Geotechnics","volume":"177 ","pages":"Article 106822"},"PeriodicalIF":5.3,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142433360","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