检索结果-南通市图书馆

Modeling unsaturated flow in fractured rocks with scaling relationships between hydraulic parameters

Journal of Rock Mechanics and Geotechnical Engineering 2022年第6期14卷 1697-1709页

作者： Yi-Feng Chen Yuke Ye Ran Hu Zhibing Yang Chuang-Bing Zhou State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan430072China Key Laboratory of Rock Mechanics in Hydraulic Structural Engineering of the Ministry of Education Wuhan430072China School of Civil Engineering and Architecture Nanchang UniversityNanchang330031China

Modeling unsaturated flow in fractured rocks is essential in various subsurface engineering applications,but it remains a great challenge due to the difficulties in determining the unsaturated hydraulic properties of rocks that contain various scales of *** is generally accepted that the van Genuchten(VG)model can be applied to fractured rocks,provided that the hydraulic parameters could be representatively *** this study,scaling relationships between the VG parameters(a and n)and hydraulic conductivity(K)across 8 orders of magnitude,from 10^(-10)m/s to 10^(-2)m/s,were proposed by statistical analysis of data obtained from 1416 soil *** correlations were then generalized to predict the upper bounds of VG parameters for fractured rocks from the K data that could be obtained more easily under field conditions,and were validated against a limited set of data from cores,fractures and fractured rocks available in the *** upper bound estimates significantly narrow the ranges of VG parameters,and the representative values of a and n for fractured rocks at the field scale can then be determined with confidence by inverse modeling using groundwater observations in saturated *** proposed methodology was applied to saturated-unsaturated flow modeling in the right-bank slope at the Baihetan dam site with a continuum approach,showing that most of the flow behaviors in fractured rocks in this complex hydrogeological condition could be properly *** proposed method overcomes difficulties in suction measurement in fractured rocks with strong heterogeneity,and provides a feasible way for modeling of saturated-unsaturated flow in fractured rocks with acceptable engineering accuracy.

关键词： Unsaturated flow van genuchten model Hydraulic properties fractured rocks Continuum approach

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A discrete model for prediction of radon flux from fractured rocks

引用

Journal of Rock Mechanics and Geotechnical Engineering 2018年第5期10卷 879-892页

作者： K.M. Ajayi K. Shahbazi R Tukkaraja K. Katzenstein Department of Mechanical Engineering South Dakota School of Mines and Technology Rapid City SD 57701 USA b Department of Mining Engineering and Management South Dakota School of Mines and Technology Rapid City SD 57701 USA Department of Geology and Geological Engineering South Dakota School of Mines and Technology Rapid City SD 57701 USA

Prediction of radon flux from the fractured zone of a propagating cave mine is basically associated with uncertainty and complexity. For instance, there is restricted access to these zones for field measure- ments, and it is quite difficult to replicate the complex nature of both natural and induced fractures in these zones in laboratory studies. Hence, a technique for predicting radon flux from a fractured rock using a discrete fracture network （DFN） model is developed to address these difficulties. This model quantifies the contribution of fractures to the total radon flux, and estimates the fracture density from a measured radon flux considering the effects of advection, diffusion, as well as radon generation and decay. Radon generation and decay are classified as reaction processes. Therefore, the equation solved is termed as the advection-diffusion-reaction equation （ADRE）. Peclet number （Pe）, a conventional dimensionless parameter that indicates the ratio of mass transport by advection to diffusion, is used to classify the transport regimes. The results show that the proposed model effectively predicts radon flux from a fractured rock. An increase in fracture density for a rock sample with uniformly distributed radon generation rate can elevate radon flux significantly compared with another rock sample with an equivalent increase in radon generation rate. In addition to Pe, two other independent dimensionless parameters （derived for radon transport through fractures） significantly affect radon dimensionless flux. Findings provide insight into radon transport through fractured rocks and can be used to improve radon control measures for proactive mitigation.

关键词： Radon mass flux Radon dimensionless flux Stochastic model Discrete fracture network (DFN) Caving mining method fractured rocks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Grouting theories and technologies for the reinforcement of fractured rocks surrounding deep roadways

引用

Deep Underground Science and Engineering 2023年第1期2卷 2-19页

作者： Hongpu Kang Wenzhou Li Fuqiang Gao Jianwei Yang CCTEG Coal Mining Research Institute BeijingChina Coal Mining Branch China Coal Research InstituteBeijingChina State Key Laboratory of Coal Mining and Clean Utilization(China Coal Research Institute) BeijingChina

Grouting is an effective method to improve the integrity and stability of fractured rocks that surround deep *** years of research and practice,various theories and a complete set of grouting technologies for deep roadways with fractured rocks have been developed and are widely applied in Chinese coal mining *** paper systematically summarizes and analyzes the research results concerning the theory,design,materials,processes,and equipment for the grouting and reinforcement of fractured rocks surrounding deep ***,in terms of grouting methods,pregrouting,groutingwhile-excavation,and postgrouting methods are explored;in terms of grouting theory,backfill grouting,compaction grouting,infiltration grouting,and fracture grouting theories are *** addition,this paper also studies grouting borehole arrangement,water-cement ratio,grouting pressure,grouting volume,grout diffusion radius,and other grouting parameters and their determination *** this basis,this paper explores the physical and mechanical properties of organic and organic-inorganic composite grouting materials,and assess grouting reinforcement quality testing methods and *** as the field cases,the application of pregrouting in front of heading faces,groutingwhile-excavation,and postgrouting in the Kouzidong coal mine are then introduced,and the effects of the grouting reinforcements are *** paper proposes a development direction for grouting technology based on problems existing in the grouting reinforcement of fractured rocks surrounding deep roadways.

关键词： deep roadways development direction field study fractured rocks grouting materials grouting methods high-pressure grouting

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Application of Stochastic Fracture Network with Numerical Fluid Flow Simulations to Groundwater Flow Modeling in fractured rocks

引用

Journal of China University of Geosciences 2001年第3期12卷 240-248页

作者： Wang Mingyu The University of Arizona, Tucson, Arizona, USA 85721 Department of Water Resources and Environmental Engineering, China University of Geosciences, Beijing 100083Chen Jinsong Wan Li Department of Water Resources and Environmental Engineering The University of Arizona Tucson Arizona USA 85721 Department of Water Resources and Environmental Engineering China University of Geosciences Beijing 100083 Department of Water Resources and Environmental Engineering China University of Geosciences Beijing 100083

The continuum approach in fluid flow modeling is generally applied to porous geological media, but has limited applicability to fractured rocks. With the presence of a discrete fracture network relatively sparsely distributed in the matrix, it may be difficult or erroneous to use a porous medium fluid flow model with continuum assumptions to describe the fluid flow in fractured rocks at small or even large field scales. A discrete fracture fluid flow approach incorporating a stochastic fracture network with numerical fluid flow simulations could have the capability of capturing fluid flow behaviors such as inhomogeneity and anisotropy while reflecting the changes of hydraulic features at different scales. Moreover, this approach can be implemented to estimate the size of the representative elementary volume (REV) in order to find out the scales at which a porous medium flow model could be applied, and then to determine the hydraulic conductivity tensor for fractured rocks. The following topics are focused on in this study: (a) conceptual discrete fracture fluid flow modeling incorporating a stochastic fracture network with numerical flow simulations; (b) estimation of REV and hydraulic conductivity tensor for fractured rocks utilizing a stochastic fracture network with numerical fluid flow simulations; (c) investigation of the effect of fracture orientation and density on the hydraulic conductivity and REV by implementing a stochastic fracture network with numerical fluid flow simulations, and (d) fluid flow conceptual models accounting for major and minor fractures in the 2 D or 3 D flow fields incorporating a stochastic fracture network with numerical fluid flow simulations.

关键词： discrete fracture fluid flow approach fractured rocks hydraulic conductivity tensor major fractures minor fractures numerical fluid flow simulations representative elementary volume stochastic fracture network.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Review of the experimental studies of the cracking behaviors of fractured rocks under compression

引用

Geohazard Mechanics 2024年第2期2卷 59-82页

作者： Jun Xu Sen Luo Xiaochun Xiao School of Mechanics and Engineering Liaoning Technical UniversityFuxin 123000China Liaoning Key Laboratory of Mining Environment and Disaster Mechanics Liaoning Technical UniversityFuxin 123000China

In recent years, many useful experimental results on the cracking behaviors of fractured rocks have been obtainedvia uniaxial, biaxial, triaxial, and Split Hopkinson Pressure Bar (SHPB) tests. In this paper, the influence of theinclination angle of flaws, number of flaws, and patterns of cracks on the mechanical properties during the failureprocess under static loading and dynamic loading conditions is introduced and reviewed. The results show thatthe presence of cracks can decrease the strengths of precracked specimens, and the inclination angles, numbers,and crack patterns of pre-existing flaws can change the mechanical properties and cracking behaviors of precracked specimens. Under static loading, the closer the inclination angle is to 90, the greater the strength, theelastic modulus, and the peak strain of the precracked specimen. However, under dynamic loading, the influenceof the inclination angle varies, and the strength can increase or decrease, possibly in a V-shaped manner. Thischange can be determined by multiple factors, such as the loading path, the materials of the precracked specimen,and the number of pre-existing cracks. Under dynamic loading, the precracked specimen usually exhibits an Xshaped conjugated failure. Additionally, some problems in the study of the cracking behaviors of fractured rocksand related future research are described and presented, and corresponding suggestions and solutions are *** particular, excavation in deep rock engineering, support of the rock surrounding the tunnel, and mining engineering have important scientific and engineering significance.

关键词： fractured rocks Mechanical properties Cracking behaviors Static or quasistatic loading Dynamic loading

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Energy Dissipation of P- and S-Waves in Fluid-Saturated rocks: An Overview Focusing on Hydraulically Connected Fractures

引用

Journal of Earth Science 2015年第6期26卷 785-790页

作者： J.German Rubino Beatriz Quintal Tobias M.Muller Luis Guarracino Ralf Janicke Holger Steeb Klaus Holliger Applied and Environmental Geophysics Group Institute of Earth Sciences University of Lausanne Energy Flagship Commonwealth Scientific and Industrial Research Organization CONICET Facultad de Ciencias Astronomicasy Geofisicas Universidad Nacional de La Plata Institute of Mechanics University of Bochum

An important characteristic of fractured rocks is their high seismic attenuation, which so far has been mainly attributed to wave-induced fluid flow（WIFF） between the fractures and the embedding matrix. The influence of fracture connectivity on seismic attenuation has, however, recently, only been investigated. Numerical compressibility and shear tests based on Biot＇s quasi-static poro-elastic equations illustrate that an important manifestation of WIFF arises in the presence of fracture connectivity. The corresponding energy loss, which can be significant for both P- and S-waves, is mainly due to fluid flow within the connected fractures and is sensitive to the permeabilities as well as the lengths and intersection angles of the fractures. Correspondingly, this phenomenon contains valuable information on the governing hydraulic properties of fractured rocks and hence should be accounted for whenever realistic seismic models of such media are needed.

关键词： fractured rocks seismic attenuation WIFF fracture connectivity embedding matrix Biot’s theory

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Impact of stress on solute transport in a fracture network: A comparison study

引用

Journal of Rock Mechanics and Geotechnical Engineering 2013年第2期5卷 110-123页

作者： Zhihong Zhao Jonny Rutqvist Colin Leung Milan Hokr Quansheng Liu Ivars Neretnieks Andrew Hoch Jirí Havlíek Yuan Wang Zhen Wang Yuexiu Wu Robert Zimmerman Royal Institute of Technology StockholmSweden Lawrence Berkeley National Laboratory BerkeleyUSA Imperial College LondonUK Technical University of Liberec Czech Republic Institute of Rock and Soil Mechanics Chinese Academy of Sciences Wuhan University Serco TAS DidcotUK Hohai University Tongji University

This paper compares numerical modeling of the effect of stress on solute transport （advection and matrix diffusion） in fractured rocks in which fracture apertures are correlated with fracture lengths. It is mainly motivated by the performance and safety assessments of underground radioactive waste repositories. Five research teams used different approaches to model stress/deformation, flow and transport pro- cesses, based on either discrete fracture network or equivalent continuum models. The simulation results derived by various teams generally demonstrated that rock stresses could significantly influence solute transport processes through stress-induced changes in fracture apertures and associated changes in per- meability. Reasonably good agreement was achieved regarding advection and matrix diffusion given the same fracture network, while some observed discrepancies could be explained by different mechanical or transport modeling approaches.

关键词： fractured rocks Solute transport Discrete element method Equivalent continuum Dual-porosity model Particle tracking method

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：