Stochastic and Centrifuge Modelling of Jointed Rock. Volume 1. Fracturing of Fractured Rock

Stochastic and Centrifuge Modelling of Jointed Rock. Volume 1. Fracturing of Fractured Rock

Author:

Publisher:

Published: 1990

Total Pages: 201

ISBN-13:

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Rock mass failure can occur through the propagation of cracks emanating from and causing coalescence of pre-existing fractures. The objective of this research was to develop a mechanical model for fracture coalescence which can be used in conjunction with numerical methods to simulate rock mass failure. The study consisted of: (1) Monitoring growth in uniaxially compressed gypsum specimens with pre-existing fractures with various arrangements. Consistent coalescence behavior as a function of preexisting fracture geometry was noted and is documented; (2) Development of an analytical coalescence model based on correlations between computed stress/strain fields and observed fracturing in the experiments. Using this analytical model, satisfactory agreement was achieved between simulated and experimental coalescence behavior as a function of pre-existing fracture geometry.


Rock Fractures and Fluid Flow

Rock Fractures and Fluid Flow

Author: Committee on Fracture Characterization and Fluid Flow

Publisher: National Academies Press

Published: 1996-09-10

Total Pages: 568

ISBN-13: 0309563488

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Scientific understanding of fluid flow in rock fractures--a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storage--has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? Among other topics, the committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling, and it provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices. With a practical and multidisciplinary outlook, this volume will be welcomed by geologists, petroleum geologists, geoengineers, geophysicists, hydrologists, researchers, educators and students in these fields, and public officials involved in geological projects.


Stochastic and Centrifuge Modelling of Jointed Rock. Volume 3. Stochastic and Topological Fracture Geometry Model

Stochastic and Centrifuge Modelling of Jointed Rock. Volume 3. Stochastic and Topological Fracture Geometry Model

Author:

Publisher:

Published: 1990

Total Pages: 307

ISBN-13:

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A hierarchical model is developed to represent the geometry of fracture sets. The most important characteristics of this model are the possibility to model sequential fracture genesis as it usually occurs in nature, and to model clustering. This model uses the inhomogeneous or the doubly stochastic (Cox) point process model to represent the midpoints of the primary set. In a second step, the fracture trace lengths of the primary set are modelled. This is done using Maximum Likelihood Estimates (MLE) of the observed data. In a third step, the secondary set is considered; in particular the independence/dependence of the two sets. The correlation of location with trace length is considered with the line-kernel function methods and the nearest neighbor fiber distance method. The hierarchical model has been applied to two cases in which detailed fracture patterns have been observed, one with a single set and one with two sets. The validity of the model was checked by visual comparison between model prediction and mapped patterns and most importantly, by statistical tests such as the second-moment analysis and the Monte Carlo test. A satisfactory fit of the predicted pattern was obtained in both cases.


Rock Mechanics

Rock Mechanics

Author: Jaak J.K. Daemen

Publisher: CRC Press

Published: 1995-01-01

Total Pages: 968

ISBN-13: 9789054105527

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This volume presents the proceedings of a symposium on rock mechanics, held in the USA in 1995. Topics covered include: rock dynamics; tool-rock interaction; radioactive waste disposal; underground mining; fragmentation and blasting; theoretical and model studies; hydrology; and rock creep.