Mechanical Behavior and Damage Fracture Mechanism of Deep Rocks

Foreword I
Foreword II
Preface
Funding Information
Contents
About the Author
1 Introduction
1.1 Effect of Stress State on the Failure Mechanical Behavior of Rocks
1.2 Effect of Loading Path on the Failure Mechanical Behavior of Rocks
1.3 Effect of High Temperature on the Failure Mechanical Behavior of Rocks
1.4 Damage Failure Mechanism of Rocks by AE and X-ray CT Observations
1.5 Main Contents in This Book
References
2 Strength, Deformation, Failure Behavior and Acoustic Emission Locations of Red Sandstone Under Triaxial Compression
2.1 Experimental Material and Testing Procedures
2.1.1 Experimental Material
2.1.2 Testing Equipment
2.1.3 Testing Procedure
2.1.4 AE Measuring Procedure
2.2 Triaxial Experimental Results of Red Sandstone
2.2.1 Deformation Behavior Under Conventional Triaxial Compression
2.2.2 Deformation Behavior in “reducing Confining Pressure” Experiments
2.2.3 Influence of the Confining Pressure on the Deformation Parameters
2.3 Triaxial Strength and Failure Behavior of Red Sandstone
2.3.1 Peak Strength and Residual Strength Behavior
2.3.2 Evaluation on Three Characteristics Stresses
2.3.3 Failure Behavior Under Triaxial Compression
2.4 Spatial AE Locations Behavior of Red Sandstone
2.5 Conclusions
References
3 Mechanical Damage Characteristics of Red Sandstone Under Triaxial Cyclic Loading
3.1 Tested Rock Material and Testing Method
3.1.1 Red Sandstone Material and Testing Equipment
3.1.2 Two Types of Triaxial Tests
3.2 Analysis of Triaxial Cyclic Experimental Results of Red Sandstone
3.2.1 Comparison Between Monotonic and Cyclic Experimental Results
3.2.2 Evolution of Crack Damage Threshold
3.3 Mechanism of Mechanical Damage of Red Sandstone
3.3.1 X-ray Micro CT Equipment and Scanning Procedure
3.3.2 Internal Damage of Sandstone Under Triaxial Monotonic and Cyclic Loading
3.4 Discussion on Evolution of Deformation Damage of Red Sandstone
3.5 Conclusions
References
4 Strength and Deformation Behavior of Red Sandstone Under Simple and Complex Loading Paths
4.1 Tested Rock Material and Testing Procedure
4.1.1 Red Sandstone Material and Specimen Preparation
4.1.2 Testing Equipment
4.1.3 Designed Loading Paths
4.2 Strength and Deformation Behavior of Red Sandstone Under Simple Loading Path
4.2.1 Deformation Behavior of Red Sandstone Under Simple Loading Path
4.2.2 Strength Behavior of Red Sandstone Under Simple Loading Path
4.2.3 Failure Mode of Red Sandstone Under Simple Loading Path
4.3 Strength and Deformation Behavior of Red Sandstone Under Complex Loading Path A
4.3.1 Deformation Behavior of Red Sandstone Under Complex Loading Path A
4.3.2 Strength and Failure Behavior of Red Sandstone Under Complex Loading Path A
4.4 Strength and Deformation Behavior of Red Sandstone Under Complex Loading Path B
4.4.1 Deformation Behavior of Red Sandstone Under Complex Loading Path B
4.4.2 Strength and Failure Behavior of Red Sandstone Under Complex Loading Path B
4.5 Discussion on Confirming Peak Strength Parameters of Red Sandstone with One Specimen
4.6 Conclusions
References
5 Mechanical, Acoustic, and Fracture Behaviors of Yellow Sandstone Specimens Under Triaxial Monotonic and Cyclic Loading
5.1 Experimental Methodology
5.1.1 Yellow Sandstone Material
5.1.2 Testing System Description
5.1.3 Experimental Procedure
5.2 Strength and Deformation Behaviors of Yellow Sandstone
5.2.1 Strength and Deformation Parameters Under Triaxial Monotonic Loading Path
5.2.2 Strength and Deformation Behavior Under Triaxial Cyclic Loading Path
5.3 Ultrasonic Velocity and AE Behaviors of Yellow Sandstone
5.3.1 P-wave Velocity of Yellow Sandstone Under Triaxial Monotonic Loading Path
5.3.2 AE Characteristics of Yellow Sandstone Under Triaxial Monotonic Loading Path
5.3.3 AE Characteristics of Yellow Sandstone Under Triaxial Cyclic Loading Path
5.4 Fracture Propagation Behavior of Yellow Sandstone
5.4.1 X-rary Micro-CT Scanning Procedure
5.4.2 Surface Crack Characteristics of Yellow Sandstone
5.4.3 Internal Crack Evolution of Yellow Sandstone
5.5 Conclusions
References
6 Triaxial Strength and Deformation Failure Behavior of Coarse Marble Under Six Different Loading Paths
6.1 Experimental Methodology
6.1.1 Coarse Marble Material and Specimen Preparation
6.1.2 Testing Procedure for Six Different Loading Paths
6.2 Mechanical Behavior of Intact Marble Under Different Loading Paths (Paths I-II)
6.3 Mechanical Behavior of Flawed Marble Under Different Loading Paths (Paths III-VI)
6.3.1 Mechanical Behavior of Flawed Marble Under Path III
6.3.2 Re-Fracture Mechanical Behavior of Flawed Marble Under Path IV and V
6.3.3 Re-Fracture Mechanical Behavior of Flawed Marble Under Path VI
6.4 Conclusions
References
7 Deformation Failure Characteristics of Crystalline Marble Under Triaxial Cyclic Loading
7.1 Crystalline Marble and Testing Procedure
7.1.1 Crystalline Marble Material and Specimen Preparation
7.1.2 Two Types of Triaxial Tests
7.2 Experimental Results of Crystalline Marble Under Triaxial Monotonic Loading
7.3 Triaxial Experimental Results of Crystalline Marble Under Simple Cyclic Loading
7.3.1 Effect of Cyclic Number and Unloading Stress Level on the Strain Behavior
7.3.2 Evolution of Elastic Modulus of Crystalline Marble with Cyclic Number
7.4 Triaxial Experimental Results of Crystalline Marble Under Complex Cyclic Loading
7.4.1 Elastic Modulus of Crystalline Marble Under Complex Cyclic Loading
7.4.2 Peak Strength of Crystalline Marble Under Complex Cyclic Loading
7.5 Conclusions
References
8 Strength, Deformability and X-ray Micro CT Observations of Deeply-Buried Marble Under Different Confining Pressures
8.1 Deeply-Buried Marble Material and Testing Procedure
8.2 Strength and Deformation Behavior of Deeply-Buried Marble
8.2.1 Uniaxial Compression and Tensile Failure Behavior of Deeply-Buried Marble
8.2.2 Triaxial Strength and Deformation Behavior of Deeply-Buried Marble
8.3 X-ray Micro CT Observations of Deep-Buried Marble
8.4 Discussion on Failure Mechanism of Deep-Buried Marble
8.5 Conclusions
References
9 Deformation and Damage Failure Behaviour of Mudstone Specimens Under Single-Stage and Multi-stage Triaxial Compression
9.1 Experimental and Numerical Methodology
9.1.1 Mudstone Material and Testing Equipment
9.1.2 Single-Stage and Multi-stage Triaxial Compression
9.1.3 Numerical Model and Micro-parameters in PFC
9.2 Mechanical Behaviour of Mudstone Under Single-stage Triaxial Compression
9.3 Mechanical Behaviour of Mudstone Under Multi-stage Triaxial Compression
9.4 Discussion of the Damage Evolution Mechanism of Mudstone
9.5 Conclusions
References
10 Deformation, Peak Strength and Crack Damage Behavior of Hollow Sandstone Under Conventional Triaxial Compression
10.1 Hollow Sandstone and Testing Procedure
10.1.1 Sandstone Material and Hollow Specimen Preparation
10.1.2 Testing Equipment and Procedure
10.2 Deformation Behavior of Hollow Sandstone
10.2.1 Determination of Deformation Parameters
10.2.2 Influence of Confining Pressure on the Deformation Behavior
10.3 Peak Strength Behavior of Hollow Sandstone
10.4 Crack Damage Behavior of Hollow Sandstone
10.4.1 Axial Deviatoric Stress-Volumetric Strain Curve
10.4.2 Influence of Hole Diameter on Crack Damage Behavior
10.4.3 Influence of Confining Pressure on Crack Damage Behavior
10.5 Conclusions
References
11 Fracture Evolution Mechanism of Hollow Sandstone Under Conventional Triaxial Compression by X-ray Micro-CT Observations and Three-Dimensional Numerical Simulations
11.1 Hollow Sandstone and X-ray Micro-CT Scanning Procedure
11.1.1 Hollow Sandstone Specimen and Mechanical Testing Procedure
11.1.2 X-ray Micro-CT Scanning Procedure
11.2 Three-Dimensional Numerical Simulation Methodology
11.2.1 Representative Volume Element Based on the RFPA3D Method
11.2.2 Damage Evolution of the RVE
11.2.3 Three-Dimensional Numerical Model
11.3 Mechanical Behavior of Hollow Sandstone by Three-Dimensional Numerical Simulations
11.3.1 Confirmation of the Micro-Parameters Based on the Intact Specimen
11.3.2 Comparison Between the Numerical Simulated and Experimental Results
11.4 Fracture Evolution Mechanism of Hollow Sandstone Under Different Confining Pressures
11.4.1 Internal Crack Mechanism of Intact Sandstone
11.4.2 Internal Crack Mechanism of Hollow Sandstone with Various Borehole Diameters
11.4.3 Effect of Borehole Size on Fracture Evolution Mechanism of Hollow Sandstone
11.5 Interpretations and Discussions on the Fracture Mechanism of Hollow Sandstone
11.5.1 Interpretations on Effect of Borehole Diameter on the Peak Strength
11.5.2 Discussions on the Effect of Confining Pressure for 3D Fracture Mechanism
11.6 Conclusions
References
12 Fracturing Mechanism of Compressed Hollow-Cylinder Sandstone Evaluated by X-ray Micro CT Scanning
12.1 Sandstone Material and Testing Procedure
12.1.1 Experimental Material
12.1.2 Mechanical Testing Equipment and Procedure
12.1.3 X-ray Micro CT Scanning Procedure
12.2 Mechanical Behaviour of Compressed Hollow-Cylinder Sandstone
12.3 Internal Damage Failure Behaviour of Compressed Hollow-Cylinder Sandstone
12.3.1 Internal Damage Failure Behaviour Before the Peak Strength
12.3.2 Internal Damage Failure Behaviour After the Peak Strength
12.3.3 Effect of Borehole Size on Internal Damage Behaviour After the Peak Strength
12.4 Discussion on the Fracturing Mechanism of Hollow-Cylinder Sandstone
12.4.1 Three-Dimensional Reconstruction of X-ray CT Images
12.4.2 Discussion on Fracturing Mechanism of Hollow-Cylinder Sandstone
12.5 Conclusions
References
13 Thermal Damage and Failure Mechanical Behavior of Granite After Exposure to Different High Temperature Treatments Under Uniaxial Compression
13.1 Experimental Material and Testing Procedure
13.1.1 Granite Material
13.1.2 Mineral Composition of Granite
13.1.3 Mechanical Testing and AE Procedure
13.2 Thermal Damage Characteristics of Granite Before Loading
13.2.1 X-ray Micro CT Scanning Procedure
13.2.2 Thermal Damage Characteristics by CT and Optical Microscopic Observation
13.3 Strength and Deformation Behavior of Granite Under Uniaxial Compression
13.3.1 Axial Stress–strain Behavior of Granite
13.3.2 Effect of Temperature on Strength and Deformation Parameters of Granite
13.4 AE Behavior of Granite During Uniaxial Compression
13.5 Internal Crack Mechanism of Granite Under Uniaxial Compression
13.6 Conclusions
References
14 Triaxial Mechanical and Permeability Behavior of Sandstone After Exposure to Different High Temperature Treatments
14.1 Experimental Material and Testing Procedure
14.1.1 Sandstone Material and Heating Procedure
14.1.2 Measurement of Physical Properties
14.1.3 Conventional Triaxial Compression and Seepage Testing Procedure
14.1.4 Brazilian Testing Procedure
14.1.5 Equipment for XRD and SEM Analysis
14.2 Results of Basic Physical Tests of Sandstone Specimen After Thermal Treatment
14.2.1 Effect of Temperature on Weight, Volume and Bulk Density of Sandstone
14.2.2 Effect of Temperature on Dynamic Parameters of Sandstone
14.3 Results of Mechanical Experiments of Sandstone Specimens After Thermal Treatment
14.3.1 Stress–strain Curves of Sandstone Under Conventional Triaxial Compression
14.3.2 Effect of Temperature on the Strength and Deformation Parameters of Sandstone
14.3.3 Effect of Temperature on the Failure Behavior of Sandstone
14.3.4 Effect of Temperature on the Tensile Strength of Sandstone
14.4 Results of Permeability Experiments on Sandstone Specimens Exposed to Heat Treatment
14.4.1 Permeability Evolution of Sandstone Under Conventional Triaxial Compression
14.4.2 Effect of Confining Pressure on Permeability Behavior of Sandstone
14.4.3 Effect of Temperature on the Permeability Behavior of Sandstone
14.5 Results of SEM and XRD Analysis
14.5.1 Effect of Temperature on the Material Composition of Sandstone
14.5.2 Effect of Temperature on the Micro-Structure of Sandstone
14.6 Conclusions
References
15 Effect of High Temperature on the Permeability Evolution and Failure Response of Granite Under Triaxial Compression
15.1 Experimental Methodology
15.1.1 Granite Material
15.1.2 Permeability Testing System and Procedure
15.1.3 Mechanical Testing System and Procedure
15.2 Effect of High Temperature on the Physical Behavior and Permeability Evolution of Granite
15.2.1 Effect of High Temperature on the Physical Behavior of Granite
15.2.2 Effect of High Temperature on Permeability Evolution of Granite Under Triaxial Compression
15.3 Effect of High Temperature on Triaxial Deformation and AE Behavior of Granite
15.3.1 Effect of High Temperature on Triaxial Stress–Strain Curves of Granite
15.3.2 Effect of High Temperature on Triaxial Deformation Parameters of Granite
15.3.3 Effect of High Temperature on the AE and Failure Behavior of Granite
15.4 Effect of High Temperature on Strength Behavior of Granite Under Triaxial Compression
15.4.1 Effect of High Temperature on Peak Strength Behavior of Granite
15.4.2 Effect of High Temperature on the Crack Damage Threshold of Granite
15.4.3 Effect of High Temperature on Hoek–Brown Criterion Strength Parameters of Granite
15.4.4 Mechanistic Control of High-Temperature Effects on Strength and Permeability of Granite
15.5 Conclusions
References
16 Experiment and Grain-Based Modelling on Damage Failure Behaviour of Granite Under Different Confining Pressures
16.1 Granite Material and Testing Procedure
16.1.1 Tested Granite Material
16.1.2 Mechanical Testing, AE and X-ray CT Scanning Procedure
16.2 Experimental Results on Damage Failure Behaviour of Granite
16.2.1 Effect of Confining Pressure on Peak Strength and Crack Damage Threshold
16.2.2 Effect of Confining Pressure on Deformation Parameters and Failure Characteristics
16.3 Grain-Based Modeling on Damage Failure Behaviour of Granite
16.3.1 Grain-Based Modelling Procedure
16.3.2 Calibrating Micro-parameters by Experimental Results
16.4 Discussion on Damage Fracture Mechanism of Granite
16.4.1 Spatial AE Behaviour of Granite Under Different Confining Pressures
16.4.2 Internal Crack Characteristics of Granite Under Triaxial Compression
16.4.3 Internal Crack Evolution Mechanism of Granite During Triaxial Compression
16.5 Conclusions
References
17 Strength and Failure Behavior of Coal Specimens with Different Diameters Under Conventional Triaxial Compression
17.1 Experimental Results of Coal Specimens with Different Diameters
17.2 Numerical Model and Micro-parameters for Coal Specimen
17.2.1 Numerical Model for Coal Specimen
17.2.2 Micro-parameters for Coal Specimen
17.3 Failure Behaviors of Coal Specimens with Different Diameters
17.3.1 Numerical Stress–Strain Curves of Coal Specimen with Different Diameters
17.3.2 Failure Behavior of Coal Specimens Under Different Confining Pressures
17.3.3 Comparison Between Numerical and Experiment Results of Coal Specimens
17.4 Strength Behaviors of Coal Specimens with Different Diameters
17.4.1 Strength Parameters of Coal Specimens with Different Diameters
17.4.2 A New Evaluation Criterion Based on Optimal Approximation Polynomial Theory
17.5 Conclusions
References