Tang / Hudson Rock Failure Mechanisms

Illustrated and Explained
1. Auflage 2011
ISBN: 978-0-203-84143-3
Verlag: Taylor & Francis
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)

E-Book, Englisch, 364 Seiten

When dealing with rock in civil engineering, mining engineering and other engineering, the process by which the rock fails under load should be understood, so that safe structures can be built on and in the rock. However, there are many ways for loading rock and rock can have a variety of idiosyncracies. This reference book provides engineers and researchers with the essential knowledge for a clear understanding of the process of rock failure under different conditions. It contains an introductory chapter explaining the role of rock failure in engineering projects plus a summary of the theories governing rock failure and an explanation of the computer simulation method. It subsquently deals in detail with explaining, simulating and illustrating rock failure in laboratory and field. The concluding chapter discusses coupled modelling and the anticipated future directions for this type of computer simulation. An appendix describing the RFPA numerical model (Rock Failure Process Analysis program) is also included.

About the Authors
Chun'an Tang has a PhD in Mining Engineering and is a Professor at the School of Civil & Hydraulic Engineering at Dalian University of Technology in China. He is an advisor for design and stablity problem modelling in mining and civil rock engineeringand and Chairman of the China National Group of the International Society for Rock Mechanics.
John Hudson is emeritus professor at Imperial College, London and is active as an independant consultant for Rock Engineering Consultants. He has a PhD in Rock Mechanics and completed over a 130 rock engineering consulting assignments in mining and civil engineering. He is a fellow at the Royal Academy of Engineering in the UK and President of the International Society for Rock Mechanics.

Autoren/Hrsg.

Tang, Chun'An

Hudson, John A.

Fachgebiete

• Technische Wissenschaften Bauingenieurwesen Bauingenieurwesen

Inhaltsverzeichnis

Preface
Acknowledgements
About the authors
List of figures
List of tables
Explanatory notes
1. Introduction
1.1 The purpose of this book
1.2 Why do things break?
1.3 Rock failure in geological and recent history
1.4 Rock failure in present day engineering
1.5 The nature of rock – a natural material
1.5.1 Discontinuities
1.5.2 Inhomogeneity
1.5.3 Anisotropy
1.5.4 Inelasticity
1.6 Numerical modelling of rock failure
1.7 The content of this book
2. Rock failure in uniaxial tension
2.1 Introduction
2.2 Specimen simulation
2.3 Numerical simulation results for the uniaxial tension case
2.4 Further studies of simulated rock failure in uniaxial tension
3. Rock failure in indirect tension
3.1 Generating a tensile stress through compressive loading
3.2 Establishing the numerical simulation model for indirect tensile strength tests
3.3 Numerical simulations of rock failure in indirect tensile strength tests
3.3.1 The disc test
3.3.1.1 Stress distribution in the discs
3.3.1.2 Effect of the material properties of theload-bearing strip on the disc test
3.3.1.3 Effect of load-bearing strip width on disc test
3.3.1.4 Effect of specimen size on the disc test
3.3.2 The plate test
3.3.3 The ring test
3.3.3.1 Stress distribution along the loadingdiameter for ring specimens
3.3.3.2 Effect of hole diameter on the failurepattern of ring specimens
3.3.3.3 Effect of hole diameter on the ringtest indirect tensile strength
4. Rock failure uniaxial compression
4.1 Introduction
4.2 Numerical illustrations of rock failure in uniaxial compression
4.2.1 Model description
4.2.2 Numerical simulation results
4.2.3 Summary of the numerical simulation observations
4.2.3.1 The complete stress–strain curve
4.2.3.2 Acoustic emission (AE) events and their locations
4.2.3.3 Stress distribution and failure-induced stress redistribution
4.3 Rock failure modes in uniaxial compression
4.4 Factors affecting rock failure behaviour
4.4.1 Model description
4.4.2 Effect of end constraint in terms of the Young’s modulusof the loading platens
4.4.3 Effect of height to width ratio (slenderness)of the specimen
4.4.4 Class I and Class II curves in uniaxial compression
4.4.5 The size effect
5. Confinement and shear
5.1 The effect of confinement
5.2 Acoustic emission during shearing
5.3 Biaxial loading
6. Effect of heterogeneity on rock failure
6.1 Introduction
6.2 Heterogeneity-induced stress fluctuations
6.2.1 Discs subjected to diametral loading
6.2.2 Rock blocks under hydrostatic stress
6.3 Heterogeneity-related seismic patterns
6.4 Influence of heterogeneity on crack propagation modes
6.4.1 Numerical specimen
6.4.2 Numerical results and discussion
6.5 The influence of heterogeneity on the meso-scale
6.5.1 Digital image based modelling method
6.5.2 Numerical model based on the digital image
6.5.3 Simulation results for uniaxial compression
6.5.4 Influence of interface strength
7. The effect of rock anisotropy on rock failure
7.1 Introduction
7.2 Numerical models
8. Loading, unloading and the Kaiser Effect
8.1 Introduction
8.2 Numerical simulation
9. Time dependency of rock failure
9.1 Introduction
9.2 A constitutive model for the time-dependent behaviour of rocks
9.3 Illustrations of time-dependent micro-structural damage
9.3.1 The creep test
9.3.2 The relaxation test
9.4 Degradation of building stones with time
10. Coalescence of fractures
10.1 Introduction
10.2 Modelling of crack growth from crack-like flaws in compression
10.2.1 An angled crack-like flaw
10.2.2 Crack growth from an array of crack-like flaws
10.2.2.1 Wing crack growth from three array flaws
10.2.2.2 Wing crack growth from randomly distributed multi-flaws
10.3 Crack growth from a pore-like flaw in compression
10.3.1 Modelling crack growth from a single hole in specimens under compression 1
10.3.1.1 Crack growth from a single hole in specimens of different width
10.3.1.2 Crack growth from a single hole with different diameters
10.3.1.3 Modelling of crack growth from an array of holes in a specimen under compression
11. Dynamic loading of rock
11.1 Introduction
11.2 The simulation models
11.3 Simulation demonstration
11.3.1 Influence of heterogeneity on stress wave propagation
11.3.2 Influence of stress wave amplitude on the fracture process and failure pattern
12. Rock failure and water flow
12.1 Introduction
12.2 Rock failure under hydraulic pressure
12.3 Illustrations of fluid flow in heterogeneous initially intact rock
12.3.1 Evolution of flow paths
12.4 Comparison with the rock degradation modelling by Yuan and Harrison (2005)
12.5 Fluid flow in initially intact rock containing block in homogeneities
13. Rock failure induced by thermal stress
13.1 Introduction
13.2 Thermally-induced rock failure
13.3 Thermal cracking of a discring model
13.4 Thermal cracking in models containing irregularly shaped inclusions
14. Slope failure in rock masses
14.1 Introduction
14.2 Strength reduction rule and determination of safety factor
14.3 A slope in a layered rock mass
14.4 A slope in a jointed rock mass
14.5 A slope in a jointed rock mass with differing joint persistence
15. The fracture process when cutting inhomogeneous rocks
15.1 Introduction
15.2 Modelling rock cutting and the failure mechanism
15.2.1 Quasi-photoelastic fringe pattern
15.2.2 Fracture pattern
15.2.3 The chipping process
15.3 The load–displacement response when cutting in homogeneous rock
15.4 The crushed zone during rock cutting
16. Rock failure around tunnels in jointed rock
16.1 Introduction
16.2 Progressive failure around a tunnel in a jointed rock mass
16.2.1 Effect of dip angles on the stability of tunnel
16.2.2 The effect of the lateral stress on the mode of tunnel failure
16.2.3 Displacements at the tunnel periphery
17. Rock failure induced by longwall coal mining
17.1 Introduction
17.2 Illustrations of longwall mining simulations
17.3 The Daliuta coal mine in China
17.3.1 The strata failure process
17.3.2 Pillar stresses
18. Gas outbursts in coal mines
18.1 Introduction
18.2 Outbursts induced by cross-cutting from rock to coal seam
18.3 Outburst as the working face approaches high methanepressure in the coal seam
19. Particle breakage and comminution
19.1 Introduction
19.2 Single particle breakage
19.2.1 Breakage of single particle under diametral loading without confinement
19.2.2 Breakage of single particle under diametral loading with confinement
19.3 Multiple particle breakage
19.3.1 Fragmentation process of a rock particle assemblage in a container
19.3.2 Force and displacement relation duringthe breakage process
19.3.3 Energy considerations
19.3.4 Size distribution
19.3.5 Influence of particle shape
20. 3-D Modelling and ‘turtle crack formation’ in rock
20.1 Introduction
20.2 The three-layer model
20.3 Fracture spacing measurements
21. Concluding remark
References and bibliography
Index
Preface