Journal of Rock Mechanics and Geotechnical Engineering最新文献_第9页

A Bayesian multi-model inference methodology for imprecise moment-independent global sensitivity analysis of rock structures 岩石结构不精确矩无关全局敏感性分析的贝叶斯多模型推理方法

1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-11-01 DOI: 10.1016/j.jrmge.2023.08.011

Akshay Kumar, Gaurav Tiwari

Traditional global sensitivity analysis (GSA) neglects the epistemic uncertainties associated with the probabilistic characteristics (i.e. type of distribution type and its parameters) of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response. This paper proposes an augmented Bayesian multi-model inference (BMMI) coupled with GSA methodology (BMMI-GSA) to address this issue by estimating the imprecision in the moment-independent sensitivity indices of rock structures arising from the small size of input data. The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties. The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo's indices by employing a reweighting approach on candidate probabilistic models. The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India. The proposed methodology was superior to the conventional GSA (neglects all epistemic uncertainties) and Bayesian coupled GSA (B-GSA) (neglects model uncertainty) due to its capability to incorporate the uncertainties in both model type and parameters of properties. Imprecise Borgonovo's indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates, which makes the user more informed in the data collection efforts. Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes. The accurate importance ranking of properties was only possible via samples of large sizes. Further, the impact of the prior knowledge in terms of prior ranges and distributions was significant; hence, any related assumption should be made carefully.

传统的全局敏感性分析(GSA)忽略了由于数据集规模小而产生的输入岩石属性的概率特征(即分布类型及其参数)相关的认知不确定性，同时映射属性对模型响应的相对重要性。本文提出了一种增强贝叶斯多模型推理(BMMI)与GSA方法(BMMI-GSA)相结合的方法来解决这一问题，该方法估计了由于输入数据规模小而导致的岩石结构的矩无关灵敏度指标的不精确性。该方法采用BMMI来量化与模型类型和输入属性参数相关的认知不确定性。通过对候选概率模型采用重加权方法，将估计的不确定性传播到矩无关Borgonovo指数的估计不精度中。该方法在印度喜马拉雅地区一个易发生应力控制破坏的岩质边坡中得到了应用。由于该方法能够同时考虑模型类型和属性参数的不确定性，因此优于传统的GSA(忽略所有认知不确定性)和贝叶斯耦合GSA(忽略模型不确定性)。通过提出的方法估计的不精确的Borgonovo指数提供了灵敏度指数的置信区间，而不是它们的定点估计，这使得用户在数据收集工作中更加知情。对不同样本量进行的分析表明，随着样本量的增加，敏感性指标的不确定性显著降低。只有通过大样本才能对属性进行准确的重要性排序。此外，先验知识在先验范围和先验分布方面的影响是显著的;因此，任何相关的假设都应谨慎做出。

{"title":"A Bayesian multi-model inference methodology for imprecise moment-independent global sensitivity analysis of rock structures","authors":"Akshay Kumar, Gaurav Tiwari","doi":"10.1016/j.jrmge.2023.08.011","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.08.011","url":null,"abstract":"Traditional global sensitivity analysis (GSA) neglects the epistemic uncertainties associated with the probabilistic characteristics (i.e. type of distribution type and its parameters) of input rock properties emanating due to the small size of datasets while mapping the relative importance of properties to the model response. This paper proposes an augmented Bayesian multi-model inference (BMMI) coupled with GSA methodology (BMMI-GSA) to address this issue by estimating the imprecision in the moment-independent sensitivity indices of rock structures arising from the small size of input data. The methodology employs BMMI to quantify the epistemic uncertainties associated with model type and parameters of input properties. The estimated uncertainties are propagated in estimating imprecision in moment-independent Borgonovo's indices by employing a reweighting approach on candidate probabilistic models. The proposed methodology is showcased for a rock slope prone to stress-controlled failure in the Himalayan region of India. The proposed methodology was superior to the conventional GSA (neglects all epistemic uncertainties) and Bayesian coupled GSA (B-GSA) (neglects model uncertainty) due to its capability to incorporate the uncertainties in both model type and parameters of properties. Imprecise Borgonovo's indices estimated via proposed methodology provide the confidence intervals of the sensitivity indices instead of their fixed-point estimates, which makes the user more informed in the data collection efforts. Analyses performed with the varying sample sizes suggested that the uncertainties in sensitivity indices reduce significantly with the increasing sample sizes. The accurate importance ranking of properties was only possible via samples of large sizes. Further, the impact of the prior knowledge in terms of prior ranges and distributions was significant; hence, any related assumption should be made carefully.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"43 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135565453","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

A coupled cryogenic thermo-hydro-mechanical model for frozen medium: Theory and implementation in FDEM 冻结介质的低温热-水-力耦合模型:理论与FDEM实现

1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-11-01 DOI: 10.1016/j.jrmge.2023.09.007

Lei Sun, Xuhai Tang, Kareem Ramzy Aboayanah, Qi Zhao, Quansheng Liu, Giovanni Grasselli

This paper presents the development of a coupled modeling approach to simulate cryogenic thermo-hydro-mechanical (THM) processes associated with a freezing medium, which is then implemented in the combined finite-discrete element method code (FDEM) for multi-physics simulation. The governing equations are deduced based on energy and mass conservation, and static equilibrium equations, considering water/ice phase change, where the strong couplings between multi-fields are supplemented by critical coupling parameters (e.g. unfrozen water content, permeability, and thermal conductivity). The proposed model is validated against laboratory and field experiments. Results show that the cryogenic THM model can well predict the evolution of strongly coupled processes observed in frozen media (e.g. heat transfer, water migration, and frost heave deformation), while also capturing, as emergent properties of the model, important phenomena (e.g. latent heat, cryogenic suction, ice expansion and distinct three-zone distribution) caused by water/ice phase change at laboratory and field scales, which are difficult to be all revealed by existing THM models. The novel modeling framework presents a gateway to further understanding and predicting the multi-physical coupling behavior of frozen media in cold regions.

本文提出了一种耦合建模方法来模拟与冷冻介质相关的低温热-水-机械(THM)过程，然后在多物理场模拟的组合有限-离散单元方法代码(FDEM)中实现。控制方程是基于能量和质量守恒，以及考虑水/冰相变的静态平衡方程推导出来的，其中多场之间的强耦合由关键耦合参数(如未冻水含量、渗透率和导热系数)补充。该模型通过室内和现场实验进行了验证。结果表明:低温THM模型可以很好地预测冻结介质中观察到的强耦合过程(如传热、水迁移和冻胀变形)的演化，同时作为模型的突现性质，也能捕捉到现有THM模型难以全部揭示的实验室和现场尺度上由水/冰相变引起的重要现象(如潜热、低温吸力、冰膨胀和明显的三带分布)。这种新的建模框架为进一步理解和预测寒冷地区冻结介质的多物理耦合行为提供了一个途径。

{"title":"A coupled cryogenic thermo-hydro-mechanical model for frozen medium: Theory and implementation in FDEM","authors":"Lei Sun, Xuhai Tang, Kareem Ramzy Aboayanah, Qi Zhao, Quansheng Liu, Giovanni Grasselli","doi":"10.1016/j.jrmge.2023.09.007","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.09.007","url":null,"abstract":"This paper presents the development of a coupled modeling approach to simulate cryogenic thermo-hydro-mechanical (THM) processes associated with a freezing medium, which is then implemented in the combined finite-discrete element method code (FDEM) for multi-physics simulation. The governing equations are deduced based on energy and mass conservation, and static equilibrium equations, considering water/ice phase change, where the strong couplings between multi-fields are supplemented by critical coupling parameters (e.g. unfrozen water content, permeability, and thermal conductivity). The proposed model is validated against laboratory and field experiments. Results show that the cryogenic THM model can well predict the evolution of strongly coupled processes observed in frozen media (e.g. heat transfer, water migration, and frost heave deformation), while also capturing, as emergent properties of the model, important phenomena (e.g. latent heat, cryogenic suction, ice expansion and distinct three-zone distribution) caused by water/ice phase change at laboratory and field scales, which are difficult to be all revealed by existing THM models. The novel modeling framework presents a gateway to further understanding and predicting the multi-physical coupling behavior of frozen media in cold regions.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"8 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135715365","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

A review of rock macro-indentation: Theories, experiments, simulations, and applications 岩石宏观压痕:理论、实验、模拟和应用综述

1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-11-01 DOI: 10.1016/j.jrmge.2023.07.022

Weiqiang Xie, Xiaoli Liu, Xiaoping Zhang, Xinmei Yang, Xiaoxiong Zhou

Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application, such as drilling, tunneling, cutting, and sawing. Over the past decades, extensive research has been conducted to understand the indentation mechanisms and responses through various approaches. This review aims to provide an overview of the current status and recent advancements in theories, experiments, numerical simulations, and applications of macro-indentation in rock engineering. It starts with elaborating on the mechanisms of macro-indentation, followed by a discussion of the merits and limitations of commonly used models. Influence factors and their effects on indentation test results are then summarized. Various numerical simulation methods for rock macro-indentation are highlighted, along with their advantages and disadvantages. Subsequently, the applications of indentation tests and indentation indices in characterizing rock properties are explored. It reveals that compression-tension, compression-shear, and composite models are widely employed in rock macro-indentation. While the compression-tension model is straightforward to use, it may overlook the anisotropic properties of rocks. On the other hand, the composite model provides a more comprehensive description of rock indentation but requires complex calculations. Additionally, factors, such as indentation rate, indenter geometry, rock type, specimen size, and confining pressure, can significantly influence the indentation results. Simulation methods for macro-indentation encompass continuous medium, discontinuous medium, and continuous-discontinuous medium methods, with selection based on their differences in principle. Furthermore, rock macro-indentation can be practically applied to mining engineering, tunneling engineering, and petroleum drilling engineering. Indentation indices serve as valuable tools for characterizing rock strength, brittleness, and drillability. This review sheds light on the development of rock macro-indentation and its extensive application in engineering practice. Specialists in the field can gain a comprehensive understanding of the indentation process and its potential in various rock engineering endeavors.

岩石宏观压痕在钻孔、隧道、切割、锯切等各种岩石工程应用中起着机械破岩的基础作用。在过去的几十年里，通过各种方法进行了广泛的研究，以了解压痕的机制和反应。本文综述了岩石工程中宏观压痕的理论、实验、数值模拟和应用的现状和最新进展。它首先详细阐述了宏观缩进的机制，然后讨论了常用模型的优点和局限性。总结了压痕试验的影响因素及其对压痕试验结果的影响。重点介绍了岩石宏观压痕的各种数值模拟方法及其优缺点。随后，探讨了压痕试验和压痕指标在岩石性质表征中的应用。结果表明，压拉、压剪和复合模型在岩石宏观压痕研究中得到了广泛应用。虽然压张模型使用简单，但它可能忽略了岩石的各向异性。另一方面，复合模型提供了更全面的岩石压痕描述，但需要复杂的计算。此外，压痕率、压痕几何形状、岩石类型、试样尺寸和围压等因素也会显著影响压痕结果。宏观压痕的模拟方法包括连续介质法、不连续介质法和连续-不连续介质法，根据它们的原理差异进行选择。此外，岩石宏观压痕可以实际应用于采矿工程、隧道工程和石油钻井工程。压痕指数是表征岩石强度、脆性和可钻性的重要工具。本文综述了岩石宏观压痕的发展及其在工程实践中的广泛应用。该领域的专家可以全面了解压痕过程及其在各种岩石工程中的潜力。

{"title":"A review of rock macro-indentation: Theories, experiments, simulations, and applications","authors":"Weiqiang Xie, Xiaoli Liu, Xiaoping Zhang, Xinmei Yang, Xiaoxiong Zhou","doi":"10.1016/j.jrmge.2023.07.022","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.07.022","url":null,"abstract":"Rock macro-indentation plays a fundamental role in mechanical rock breaking for various rock engineering application, such as drilling, tunneling, cutting, and sawing. Over the past decades, extensive research has been conducted to understand the indentation mechanisms and responses through various approaches. This review aims to provide an overview of the current status and recent advancements in theories, experiments, numerical simulations, and applications of macro-indentation in rock engineering. It starts with elaborating on the mechanisms of macro-indentation, followed by a discussion of the merits and limitations of commonly used models. Influence factors and their effects on indentation test results are then summarized. Various numerical simulation methods for rock macro-indentation are highlighted, along with their advantages and disadvantages. Subsequently, the applications of indentation tests and indentation indices in characterizing rock properties are explored. It reveals that compression-tension, compression-shear, and composite models are widely employed in rock macro-indentation. While the compression-tension model is straightforward to use, it may overlook the anisotropic properties of rocks. On the other hand, the composite model provides a more comprehensive description of rock indentation but requires complex calculations. Additionally, factors, such as indentation rate, indenter geometry, rock type, specimen size, and confining pressure, can significantly influence the indentation results. Simulation methods for macro-indentation encompass continuous medium, discontinuous medium, and continuous-discontinuous medium methods, with selection based on their differences in principle. Furthermore, rock macro-indentation can be practically applied to mining engineering, tunneling engineering, and petroleum drilling engineering. Indentation indices serve as valuable tools for characterizing rock strength, brittleness, and drillability. This review sheds light on the development of rock macro-indentation and its extensive application in engineering practice. Specialists in the field can gain a comprehensive understanding of the indentation process and its potential in various rock engineering endeavors.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135670397","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

Efficient slope reliability analysis under soil spatial variability using maximum entropy distribution with fractional moments 基于分数阶矩最大熵分布的土壤空间变异性下边坡可靠度分析

1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-11-01 DOI: 10.1016/j.jrmge.2023.09.006

Chengxin Feng, Marcos A. Valdebenito, Marcin Chwała, Kang Liao, Matteo Broggi, Michael Beer

Spatial variability of soil properties imposes a challenge for practical analysis and design in geotechnical engineering. The latter is particularly true for slope stability assessment, where the effects of uncertainty are synthesized in the so-called probability of failure. This probability quantifies the reliability of a slope and its numerical calculation is usually quite involved from a numerical viewpoint. In view of this issue, this paper proposes an approach for failure probability assessment based on Latinized partially stratified sampling and maximum entropy distribution with fractional moments. The spatial variability of geotechnical properties is represented by means of random fields and the Karhunen-Loève expansion. Then, failure probabilities are estimated employing maximum entropy distribution with fractional moments. The application of the proposed approach is examined with two examples: a case study of an undrained slope and a case study of a slope with cross-correlated random fields of strength parameters under a drained slope. The results show that the proposed approach has excellent accuracy and high efficiency, and it can be applied straightforwardly to similar geotechnical engineering problems.

土壤性质的空间变异性对岩土工程的实际分析和设计提出了挑战。后者尤其适用于边坡稳定性评估，其中不确定性的影响综合在所谓的破坏概率中。这种概率量化了边坡的可靠度，从数值的角度来看，它的数值计算通常是相当复杂的。针对这一问题，提出了一种基于拉丁化部分分层抽样和分数阶矩最大熵分布的失效概率评估方法。岩土力学性质的空间变异性由随机场和karhunen - lo展开表示。然后，利用分数阶矩最大熵分布估计失效概率。本文通过两个实例检验了该方法的应用:一个是不排水边坡的实例研究，另一个是排水边坡下具有强度参数互相关随机场的边坡的实例研究。结果表明，该方法精度高、效率高，可直接应用于类似岩土工程问题。

{"title":"Efficient slope reliability analysis under soil spatial variability using maximum entropy distribution with fractional moments","authors":"Chengxin Feng, Marcos A. Valdebenito, Marcin Chwała, Kang Liao, Matteo Broggi, Michael Beer","doi":"10.1016/j.jrmge.2023.09.006","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.09.006","url":null,"abstract":"Spatial variability of soil properties imposes a challenge for practical analysis and design in geotechnical engineering. The latter is particularly true for slope stability assessment, where the effects of uncertainty are synthesized in the so-called probability of failure. This probability quantifies the reliability of a slope and its numerical calculation is usually quite involved from a numerical viewpoint. In view of this issue, this paper proposes an approach for failure probability assessment based on Latinized partially stratified sampling and maximum entropy distribution with fractional moments. The spatial variability of geotechnical properties is represented by means of random fields and the Karhunen-Loève expansion. Then, failure probabilities are estimated employing maximum entropy distribution with fractional moments. The application of the proposed approach is examined with two examples: a case study of an undrained slope and a case study of a slope with cross-correlated random fields of strength parameters under a drained slope. The results show that the proposed approach has excellent accuracy and high efficiency, and it can be applied straightforwardly to similar geotechnical engineering problems.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"27 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135412593","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

A coupled thermo-mechanical peridynamic model for fracture behavior of granite subjected to heating and water-cooling processes 花岗岩在加热和水冷过程中断裂行为的热-力耦合动力学模型

1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-11-01 DOI: 10.1016/j.jrmge.2023.07.021

Luming Zhou, Zhende Zhu

Thermal damage and thermal fracture of rocks are two important indicators in geothermal mining projects. This paper investigates the effects of heating and water-cooling on granite specimens at various temperatures. The laboratory uniaxial compression experiments were also conducted. Then, a coupled thermo-mechanical ordinary state-based peridynamic (OSB-PD) model and corresponding numerical scheme were developed to simulate the damage of rocks after the heating and cooling processes, and the change of crack evolution process was predicted. The results demonstrate that elevated heating temperatures exacerbate the thermal damage to the specimens, resulting in a decrease in peak strength and an increase in ductility of granite. The escalating occurrence of thermal-induced cracks significantly affects the crack evolution process during the loading phase. The numerical results accurately reproduce the damage and fracture characteristics of the granite under different final heating temperatures (FHTs), which are consistent with the test results in terms of strength, crack evolution process, and failure mode.

岩石热损伤和热破裂是地热开采项目的两个重要指标。研究了不同温度下加热和水冷却对花岗岩试样的影响。进行了室内单轴压缩实验。在此基础上，建立了热-力耦合普通状态周动力学(OSB-PD)模型和相应的数值格式，模拟了岩石在加热和冷却过程后的损伤，并预测了裂纹演化过程的变化。结果表明:加热温度升高加剧了试样的热损伤，导致花岗岩峰值强度降低，延性增加;在加载阶段，热致裂纹的逐渐发生显著影响裂纹的演化过程。数值结果准确再现了花岗岩在不同终热温度下的损伤和断裂特征，在强度、裂纹演化过程和破坏模式等方面与试验结果一致。

{"title":"A coupled thermo-mechanical peridynamic model for fracture behavior of granite subjected to heating and water-cooling processes","authors":"Luming Zhou, Zhende Zhu","doi":"10.1016/j.jrmge.2023.07.021","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.07.021","url":null,"abstract":"Thermal damage and thermal fracture of rocks are two important indicators in geothermal mining projects. This paper investigates the effects of heating and water-cooling on granite specimens at various temperatures. The laboratory uniaxial compression experiments were also conducted. Then, a coupled thermo-mechanical ordinary state-based peridynamic (OSB-PD) model and corresponding numerical scheme were developed to simulate the damage of rocks after the heating and cooling processes, and the change of crack evolution process was predicted. The results demonstrate that elevated heating temperatures exacerbate the thermal damage to the specimens, resulting in a decrease in peak strength and an increase in ductility of granite. The escalating occurrence of thermal-induced cracks significantly affects the crack evolution process during the loading phase. The numerical results accurately reproduce the damage and fracture characteristics of the granite under different final heating temperatures (FHTs), which are consistent with the test results in terms of strength, crack evolution process, and failure mode.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"45 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135564427","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

Three-dimensional finite element simulation and reconstruction of jointed rock models using CT scanning and photogrammetry 利用CT扫描和摄影测量技术对节理岩石模型进行三维有限元模拟和重建

1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-11-01 DOI: 10.1016/j.jrmge.2023.08.008

Yingxian Lang, Zhengzhao Liang, Zhuo Dong

The geometry of joints has a significant influence on the mechanical properties of rocks. To simplify the curved joint shapes in rocks, the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical simulations. In this study, the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample, respectively. To describe the joint geometry, the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock models. For comparison tests, the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing method. The results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of joints. The presence of joints reduces the uniaxial compressive strength (UCS), elastic modulus, and released acoustic emission (AE) energy of rocks by 37%–67%, 21%–24%, and 52%–90%, respectively. Compared to the simplified joint sample, the proposed photogrammetry-based numerical model makes the most of the limited geometry information of joints. The UCS, accumulative released AE energy, and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based sample. The UCS value of the simplified joint sample (i.e. 38.5 MPa) is much lower than that of the CT-based sample (i.e. 72.3 MPa). Additionally, the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based sample. CT scanning provides a reliable means to visualize the joints in rocks, which can be used to verify the reliability of photogrammetry techniques. The application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.

节理的几何形状对岩石的力学性能有重要影响。为了简化岩石中的弯曲节理形态，在大多数室内实验和数值模拟中，节理形态通常被视为直线或平面。本研究采用计算机断层扫描(CT)和摄影测量法分别获得石灰石样品的内部和表面节理结构。为了描述节理的几何形状，应用边缘检测算法和三维矩阵映射方法重建基于ct和基于摄影测量的节理岩石模型。为了进行对比试验，采用并行计算方法对完整岩样和简化为平面的节理岩样进行了数值单轴压缩试验。结果表明，节理岩石的力学特性和破坏过程受节理几何形状的显著影响。节理的存在使岩石的单轴抗压强度、弹性模量和声发射能量分别降低37% ~ 67%、21% ~ 24%和52% ~ 90%。与简化的节理样本相比，本文提出的基于摄影测量的数值模型充分利用了节理有限的几何信息。实验发现，基于摄影测量的样品的声发射强度、累积释放声发射能量和弹性模量与基于ct的样品非常接近。简化节理试样的UCS值(38.5 MPa)远低于ct基试样的UCS值(72.3 MPa)。简化节理试样的声发射累计释放能比基于ct的试样低3.899倍。CT扫描提供了一种可靠的手段来可视化岩石中的节理，这可以用来验证摄影测量技术的可靠性。应用基于摄影测量的样品可以对节理岩石的力学特性进行详细的分析。

{"title":"Three-dimensional finite element simulation and reconstruction of jointed rock models using CT scanning and photogrammetry","authors":"Yingxian Lang, Zhengzhao Liang, Zhuo Dong","doi":"10.1016/j.jrmge.2023.08.008","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.08.008","url":null,"abstract":"The geometry of joints has a significant influence on the mechanical properties of rocks. To simplify the curved joint shapes in rocks, the joint shape is usually treated as straight lines or planes in most laboratory experiments and numerical simulations. In this study, the computerized tomography (CT) scanning and photogrammetry were employed to obtain the internal and surface joint structures of a limestone sample, respectively. To describe the joint geometry, the edge detection algorithms and a three-dimensional (3D) matrix mapping method were applied to reconstruct CT-based and photogrammetry-based jointed rock models. For comparison tests, the numerical uniaxial compression tests were conducted on an intact rock sample and a sample with a joint simplified to a plane using the parallel computing method. The results indicate that the mechanical characteristics and failure process of jointed rocks are significantly affected by the geometry of joints. The presence of joints reduces the uniaxial compressive strength (UCS), elastic modulus, and released acoustic emission (AE) energy of rocks by 37%–67%, 21%–24%, and 52%–90%, respectively. Compared to the simplified joint sample, the proposed photogrammetry-based numerical model makes the most of the limited geometry information of joints. The UCS, accumulative released AE energy, and elastic modulus of the photogrammetry-based sample were found to be very close to those of the CT-based sample. The UCS value of the simplified joint sample (i.e. 38.5 MPa) is much lower than that of the CT-based sample (i.e. 72.3 MPa). Additionally, the accumulative released AE energy observed in the simplified joint sample is 3.899 times lower than that observed in the CT-based sample. CT scanning provides a reliable means to visualize the joints in rocks, which can be used to verify the reliability of photogrammetry techniques. The application of the photogrammetry-based sample enables detailed analysis for estimating the mechanical properties of jointed rocks.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"106 9","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135514910","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

Permeability evolution mechanism and the optimum permeability determination of uranium leaching from low-permeability sandstone treated with low-frequency vibration 低频振动处理低渗透砂岩铀浸出渗透率演化机制及最佳渗透率的确定

IF 7.3 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-10-01 DOI: 10.1016/j.jrmge.2022.12.031

Yong Zhao , Xiqi Li , Lin Lei , Ling Chen , Zhiping Luo

Low-frequency vibrations can effectively improve natural sandstone permeability, and higher vibration frequency is associated with larger permeability. However, the optimum permeability and permeability evolution mechanism for uranium leaching and the relationship between permeability and the change of chemical reactive rate affecting uranium leaching have not been determined. To solve the above problems, in this study, identical homogeneous sandstone samples were selected to simulate low-permeability sandstone; a permeability evolution model considering the combined action of vibration stress, pore water pressure, water flow impact force, and chemical erosion was established; and vibration leaching experiments were performed to test the model accuracy. Both the permeability and chemical reactions were found to simultaneously restrict U⁶⁺ leaching, and the vibration treatment increased the permeability, causing the U⁶⁺ leaching reaction to no longer be diffusion-constrained but to be primarily controlled by the reaction rate. Changes of the model calculation parameters were further analyzed to determine the permeability evolution mechanism under the influence of vibration and chemical erosion, to prove the correctness of the mechanism according to the experimental results, and to develop a new method for determining the optimum permeability in uranium leaching. The uranium leaching was found to primarily follow a process consisting of (1) a permeability control stage, (2) achieving the optimum permeability, (3) a chemical reactive rate control stage, and (4) a channel flow stage. The resolution of these problems is of great significance for facilitating the application and promotion of low-frequency vibration in the CO₂ + O₂ leaching process.

低频振动能有效提高天然砂岩的渗透率，振动频率越高，渗透率越大。然而，铀浸出的最佳渗透率和渗透率演化机制以及渗透率与影响铀浸出的化学反应速率变化之间的关系尚未确定。为解决上述问题，本研究选取相同均质砂岩样品模拟低渗透砂岩;建立了考虑振动应力、孔隙水压力、水流冲击力和化学侵蚀共同作用的渗透率演化模型;并进行了振动浸出试验，验证了模型的准确性。发现渗透性和化学反应同时限制U6+浸出，振动处理增加了渗透性，使U6+浸出反应不再受扩散限制，而主要受反应速率控制。进一步分析了模型计算参数的变化，确定了振动和化学侵蚀作用下渗透率演化机理，并根据实验结果验证了机理的正确性，为确定铀浸出最佳渗透率提供了新的方法。发现铀浸出主要遵循以下过程:(1)渗透率控制阶段，(2)达到最佳渗透率，(3)化学反应速率控制阶段，(4)通道流动阶段。这些问题的解决对于促进低频振动在CO2 + O2浸出过程中的应用和推广具有重要意义。

{"title":"Permeability evolution mechanism and the optimum permeability determination of uranium leaching from low-permeability sandstone treated with low-frequency vibration","authors":"Yong Zhao , Xiqi Li , Lin Lei , Ling Chen , Zhiping Luo","doi":"10.1016/j.jrmge.2022.12.031","DOIUrl":"10.1016/j.jrmge.2022.12.031","url":null,"abstract":"<div><p>Low-frequency vibrations can effectively improve natural sandstone permeability, and higher vibration frequency is associated with larger permeability. However, the optimum permeability and permeability evolution mechanism for uranium leaching and the relationship between permeability and the change of chemical reactive rate affecting uranium leaching have not been determined. To solve the above problems, in this study, identical homogeneous sandstone samples were selected to simulate low-permeability sandstone; a permeability evolution model considering the combined action of vibration stress, pore water pressure, water flow impact force, and chemical erosion was established; and vibration leaching experiments were performed to test the model accuracy. Both the permeability and chemical reactions were found to simultaneously restrict U<sup>6+</sup> leaching, and the vibration treatment increased the permeability, causing the U<sup>6+</sup> leaching reaction to no longer be diffusion-constrained but to be primarily controlled by the reaction rate. Changes of the model calculation parameters were further analyzed to determine the permeability evolution mechanism under the influence of vibration and chemical erosion, to prove the correctness of the mechanism according to the experimental results, and to develop a new method for determining the optimum permeability in uranium leaching. The uranium leaching was found to primarily follow a process consisting of (1) a permeability control stage, (2) achieving the optimum permeability, (3) a chemical reactive rate control stage, and (4) a channel flow stage. The resolution of these problems is of great significance for facilitating the application and promotion of low-frequency vibration in the CO<sub>2</sub> + O<sub>2</sub> leaching process.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2597-2610"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48187151","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

Displacement-based back analysis of mitigating the effects of displacement loss in underground engineering 基于位移的反分析法减轻地下工程位移损失的影响

IF 7.3 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-10-01 DOI: 10.1016/j.jrmge.2022.12.036

Hui Li, Weizhong Chen, Xianjun Tan

Displacement-monitoring-based back analysis is a popular method for geomechanical parameter estimation. However, due to the delayed installation of multi-point extensometers, the monitoring curve is only a part of the overall one, leading to displacement loss. Besides, the monitoring and construction time on the monitoring curve is difficult to determine. In the literature, the final displacement was selected for the back analysis, which could induce unreliable results. In this paper, a displacement-based back analysis method to mitigate the influence of displacement loss is developed. A robust hybrid optimization algorithm is proposed as a substitute for time-consuming numerical simulation. It integrates the strengths of the nonlinear mapping and prediction capability of the support vector machine (SVM) algorithm, the global searching and optimization characteristics of the optimized particle swarm optimization (OPSO) algorithm, and the nonlinear numerical simulation capability of ABAQUS. To avoid being trapped in the local optimum and to improve the efficiency of optimization, the standard PSO algorithm is improved and is compared with other three algorithms (genetic algorithm (GA), simulated annealing (SA), and standard PSO). The results indicate the superiority of OPSO algorithm. Finally, the hybrid optimization algorithm is applied to an engineering project. The back-analyzed parameters are submitted to numerical analysis, and comparison between the calculated and monitoring displacement curve shows that this hybrid algorithm can offer a reasonable reference for geomechanical parameters estimation.

基于位移监测的反分析是一种常用的地质力学参数估计方法。然而，由于多点延伸仪的安装延迟，监测曲线只是整体曲线的一部分，导致位移损失。此外，监测曲线上的监测和施工时间难以确定。在文献中，选择最终位移进行反分析，这可能导致不可靠的结果。本文提出了一种基于位移的反分析方法，以减轻位移损失的影响。提出了一种鲁棒混合优化算法来代替耗时的数值模拟。它综合了支持向量机(SVM)算法的非线性映射和预测能力、优化粒子群优化(OPSO)算法的全局搜索和优化特性以及ABAQUS的非线性数值模拟能力的优点。为了避免陷入局部最优，提高优化效率，对标准粒子群算法进行了改进，并与遗传算法(GA)、模拟退火算法(SA)和标准粒子群算法(PSO)进行了比较。结果表明了OPSO算法的优越性。最后，将混合优化算法应用于工程实例。将反分析参数进行数值分析，计算位移曲线与监测位移曲线对比表明，该混合算法可为地质力学参数估计提供合理参考。

{"title":"Displacement-based back analysis of mitigating the effects of displacement loss in underground engineering","authors":"Hui Li, Weizhong Chen, Xianjun Tan","doi":"10.1016/j.jrmge.2022.12.036","DOIUrl":"10.1016/j.jrmge.2022.12.036","url":null,"abstract":"<div><p>Displacement-monitoring-based back analysis is a popular method for geomechanical parameter estimation. However, due to the delayed installation of multi-point extensometers, the monitoring curve is only a part of the overall one, leading to displacement loss. Besides, the monitoring and construction time on the monitoring curve is difficult to determine. In the literature, the final displacement was selected for the back analysis, which could induce unreliable results. In this paper, a displacement-based back analysis method to mitigate the influence of displacement loss is developed. A robust hybrid optimization algorithm is proposed as a substitute for time-consuming numerical simulation. It integrates the strengths of the nonlinear mapping and prediction capability of the support vector machine (SVM) algorithm, the global searching and optimization characteristics of the optimized particle swarm optimization (OPSO) algorithm, and the nonlinear numerical simulation capability of ABAQUS. To avoid being trapped in the local optimum and to improve the efficiency of optimization, the standard PSO algorithm is improved and is compared with other three algorithms (genetic algorithm (GA), simulated annealing (SA), and standard PSO). The results indicate the superiority of OPSO algorithm. Finally, the hybrid optimization algorithm is applied to an engineering project. The back-analyzed parameters are submitted to numerical analysis, and comparison between the calculated and monitoring displacement curve shows that this hybrid algorithm can offer a reasonable reference for geomechanical parameters estimation.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2626-2638"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49272148","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 thawing-induced softening on fracture behaviors of frozen rock 解冻诱导软化对冻土断裂行为的影响

1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-10-01 DOI: 10.1016/j.jrmge.2023.07.016

Ting Wang, Hailiang Jia, Qiang Sun, Xianjun Tan, Liyun Tang

Due to the presence of ice and unfrozen water in pores of frozen rock, the rock fracture behaviors are susceptible to temperature In this study, the potential thawing-induced softening effects on the fracture behaviors of frozen rock is evaluated by testing the tension fracture toughness (KIC) of frozen rock at different temperatures (i.e. −20 °C, −15 °C, −12 °C, −10 °C, −8 °C, −6 °C, −4 °C, −2 °C, and 0 °C). Acoustic emission (AE) and digital image correlation (DIC) methods are utilized to analyze the microcrack propagation during fracturing. The melting of pore ice is measured using nuclear magnetic resonance (NMR) method. The results indicate that: (1) The KIC of frozen rock decreases moderately between −20 °C and −4 °C, and rapidly between −4 °C and 0 °C. (2) At −20 °C to −4 °C, the fracturing process, deduced from the DIC results at the notch tip, exhibits three stages: elastic deformation, microcrack propagation and microcrack coalescence. However, at −4 °C–0 °C, only the latter two stages are observed. (3) At −4 °C–0 °C, the AE activities during fracturing are less than that at −20 °C to −4 °C, while more small events are reported. (4) The NMR results demonstrate a reverse variation trend in pore ice content with increasing temperature, that is, a moderate decrease is followed by a sharp decrease and −4 °C is exactly the critical temperature. Next, we interpret the thawing-induced softening effect by linking the evolution in microscopic structure of frozen rock with its macroscopic fracture behaviors as follow: from −20 °C to −4 °C, the thickening of the unfrozen water film diminishes the cementation strength between ice and rock skeleton, leading to the decrease in fracture parameters. From −4 °C to 0 °C, the cementation effect of ice almost vanishes, and the filling effect of pore ice is reduced significantly, which facilitates microcrack propagation and thus the easier fracture of frozen rocks.

由于冻结岩石孔隙中存在冰和未冻水，岩石的断裂行为容易受到温度的影响。本研究通过测试不同温度(即- 20°C、- 15°C、- 12°C、- 10°C、- 8°C、- 6°C、- 4°C、- 2°C和0°C)下冻结岩石的拉伸断裂韧性(KIC)，来评估解冻对冻结岩石断裂行为的潜在软化效应。采用声发射(AE)和数字图像相关(DIC)方法对压裂过程中的微裂纹扩展进行了分析。采用核磁共振(NMR)方法对孔隙冰的融化进行了测量。结果表明:(1)冻结岩石的KIC在−20℃~−4℃之间略有下降，在−4℃~ 0℃之间急剧下降。(2)在- 20℃~ - 4℃时，缺口尖端的DIC结果推导出的断裂过程分为弹性变形、微裂纹扩展和微裂纹合并三个阶段。然而，在- 4°C - 0°C时，只观察到后两个阶段。(3)在- 4°C ~ 0°C，压裂过程中的声发射活动比- 20°C ~ - 4°C时少，但小事件较多。(4)核磁共振结果表明，孔隙冰含量随温度的升高呈相反的变化趋势，即先适度减小后急剧减小，−4℃正是临界温度。接下来，我们将冻结岩石微观结构的演变与宏观断裂行为联系起来，解释了解冻引起的软化效应:从- 20°C到- 4°C，未冻水膜的增厚降低了冰与岩石骨架之间的胶结强度，导致断裂参数减小。从−4℃到0℃，冰的胶结作用几乎消失，孔隙冰的填充作用明显减弱，有利于微裂纹的扩展，使冻结岩石更容易破裂。

{"title":"Effects of thawing-induced softening on fracture behaviors of frozen rock","authors":"Ting Wang, Hailiang Jia, Qiang Sun, Xianjun Tan, Liyun Tang","doi":"10.1016/j.jrmge.2023.07.016","DOIUrl":"https://doi.org/10.1016/j.jrmge.2023.07.016","url":null,"abstract":"Due to the presence of ice and unfrozen water in pores of frozen rock, the rock fracture behaviors are susceptible to temperature In this study, the potential thawing-induced softening effects on the fracture behaviors of frozen rock is evaluated by testing the tension fracture toughness (KIC) of frozen rock at different temperatures (i.e. −20 °C, −15 °C, −12 °C, −10 °C, −8 °C, −6 °C, −4 °C, −2 °C, and 0 °C). Acoustic emission (AE) and digital image correlation (DIC) methods are utilized to analyze the microcrack propagation during fracturing. The melting of pore ice is measured using nuclear magnetic resonance (NMR) method. The results indicate that: (1) The KIC of frozen rock decreases moderately between −20 °C and −4 °C, and rapidly between −4 °C and 0 °C. (2) At −20 °C to −4 °C, the fracturing process, deduced from the DIC results at the notch tip, exhibits three stages: elastic deformation, microcrack propagation and microcrack coalescence. However, at −4 °C–0 °C, only the latter two stages are observed. (3) At −4 °C–0 °C, the AE activities during fracturing are less than that at −20 °C to −4 °C, while more small events are reported. (4) The NMR results demonstrate a reverse variation trend in pore ice content with increasing temperature, that is, a moderate decrease is followed by a sharp decrease and −4 °C is exactly the critical temperature. Next, we interpret the thawing-induced softening effect by linking the evolution in microscopic structure of frozen rock with its macroscopic fracture behaviors as follow: from −20 °C to −4 °C, the thickening of the unfrozen water film diminishes the cementation strength between ice and rock skeleton, leading to the decrease in fracture parameters. From −4 °C to 0 °C, the cementation effect of ice almost vanishes, and the filling effect of pore ice is reduced significantly, which facilitates microcrack propagation and thus the easier fracture of frozen rocks.","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134936111","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

Analysis of rockburst mechanism and warning based on microseismic moment tensors and dynamic Bayesian networks 基于微震矩张量和动态贝叶斯网络的岩爆机理及预警分析

IF 7.3 1区工程技术 Q1 ENGINEERING, GEOLOGICAL

Journal of Rock Mechanics and Geotechnical Engineering

Pub Date : 2023-10-01 DOI: 10.1016/j.jrmge.2022.12.005

Haoyu Mao , Nuwen Xu , Xiang Li , Biao Li , Peiwei Xiao , Yonghong Li , Peng Li

One of the major factors inhibiting the construction of deep underground projects is the risk posed by rockbursts. A study was conducted on the access tunnel of the Shuangjiangkou hydropower station to determine the evolutionary mechanism of microfractures within the surrounding rock mass during rockburst development and develop a rockburst warning model. The study area was chosen through the combination of field studies with an analysis of the spatial and temporal distribution of microseismic (MS) events. The moment tensor inversion method was adopted to study rockburst mechanism, and a dynamic Bayesian network (DBN) was applied to investigating the sensitivity of MS source parameters for rockburst warnings. A MS multivariable rockburst warning model was proposed and validated using two case studies. The results indicate that fractures in the surrounding rock mass during the development of strain-structure rockbursts initially show shear failure and are then followed by tensile failure. The effectiveness of the DBN-based rockburst warning model was demonstrated using self-validation and K-fold cross-validation. Moment magnitude and source radius are the most sensitive factors based on an investigation of the influence on the parent and child nodes in the model, which can serve as important standards for rockburst warnings. The proposed rockburst warning model was found to be effective when applied to two actual projects.

岩爆风险是制约深埋地下工程建设的主要因素之一。以双江口水电站引水隧洞为研究对象，确定岩爆发展过程中围岩微裂缝的演化机制，建立岩爆预警模型。通过实地研究和微震事件时空分布分析相结合的方法选择了研究区域。采用矩张量反演方法研究岩爆机理，采用动态贝叶斯网络(DBN)研究MS源参数对岩爆预警的敏感性。提出了一种多变量MS岩爆预警模型，并通过两个实例进行了验证。结果表明:在应变结构岩爆发展过程中，围岩裂隙首先表现为剪切破坏，然后是拉伸破坏;通过自验证和K-fold交叉验证，验证了基于dbn的岩爆预警模型的有效性。通过对模型中父节点和子节点影响的研究，发现弯矩震级和震源半径是最敏感的因素，可作为岩爆预警的重要标准。通过对两个工程实例的应用，验证了所建立的岩爆预警模型的有效性。

{"title":"Analysis of rockburst mechanism and warning based on microseismic moment tensors and dynamic Bayesian networks","authors":"Haoyu Mao , Nuwen Xu , Xiang Li , Biao Li , Peiwei Xiao , Yonghong Li , Peng Li","doi":"10.1016/j.jrmge.2022.12.005","DOIUrl":"10.1016/j.jrmge.2022.12.005","url":null,"abstract":"<div><p>One of the major factors inhibiting the construction of deep underground projects is the risk posed by rockbursts. A study was conducted on the access tunnel of the Shuangjiangkou hydropower station to determine the evolutionary mechanism of microfractures within the surrounding rock mass during rockburst development and develop a rockburst warning model. The study area was chosen through the combination of field studies with an analysis of the spatial and temporal distribution of microseismic (MS) events. The moment tensor inversion method was adopted to study rockburst mechanism, and a dynamic Bayesian network (DBN) was applied to investigating the sensitivity of MS source parameters for rockburst warnings. A MS multivariable rockburst warning model was proposed and validated using two case studies. The results indicate that fractures in the surrounding rock mass during the development of strain-structure rockbursts initially show shear failure and are then followed by tensile failure. The effectiveness of the DBN-based rockburst warning model was demonstrated using self-validation and <em>K</em>-fold cross-validation. Moment magnitude and source radius are the most sensitive factors based on an investigation of the influence on the parent and child nodes in the model, which can serve as important standards for rockburst warnings. The proposed rockburst warning model was found to be effective when applied to two actual projects.</p></div>","PeriodicalId":54219,"journal":{"name":"Journal of Rock Mechanics and Geotechnical Engineering","volume":"15 10","pages":"Pages 2521-2538"},"PeriodicalIF":7.3,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43114799","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: 7