title of the thesis - Department of Geology - Queen's University

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$Fayek & Kyser 2000 uraninite fractionations.pdf - Queen's University$

Figure D16 Phase 2 model depicting model and boundary conditions. The model consists of a rockmass, joints (orange) and an excavation, outlined in black. This figure shows the first stage in a two-stage model where material within the excavation removed in the second stage. D.2.2 Boundary Conditions The model is subject to an external stress field where the maximum principal stress is directed EW and the minimum principal stress is oriented NS. An intermediate, out-of-plane stress is applied in the vertical direction. Phase 2 uses a positive sign convention to denote compressive stress. Movement on the model boundaries is restricted by pinning the corners of the model so that NS or EW movement of the model is not possible. This is appropriate as it simulates the confined conditions of the mine within the Canadian Shield. 178
Staged models were created in which the medium and discontinuities are allowed to come to equilibrium before introducing the excavation. In this manner the stress conditions simulate stress conditions within the mine and influence of the excavation on the distribution of stress can be better understood. This approach did not yield appreciable differences from the applying external stresses to a model complete with an excavation. Unlike models created in UDEC, tectonically loaded models were not created due to limitations on the program version. Phase 2 results are shown for Case 1, described in Chapter 4, in which all faults are assigned equal properties. Faults within the model are progressively weakened to induce slip by varying the cohesion and angle of internal friction. Material properties were also tested to examine the effect of rock mass strength on fault slip. D.3 Phase 2 Model Results Results for the 7200, 7400 and 7530 Level indicate that stress is bounded by faults rather than accumulated along weaker geological structure. This indicates that seismicity is a result of the stress concentrations that occurs between faults, rather than slip on the mine-scale structures. The stress distribution closely matches the distribution of seismicity in the January 2006- December 2007 time period. Areas of high maximum and differential stress are areas of dense event localization, while areas of low modelled stress are areas of sparse activity. In plastic models, yielding occurs directly to the north and south of the excavation and displacement is modelled along discontinuities within this yielded zone. Low stress is modelled in this yield zone and correspondingly, there is little-to no seismicity. 179
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THE INFLUENCES OF STRESS AND STRUCT
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esulting in increased stress to the
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Table of Contents Abstract.........
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4.6.1 Fracture Reactivation........
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List of Figures Figure 1.1: Locatio
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Figure 3.23: Preliminary stress inv
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Figure B11: Events between Jan 1, 2
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List of Tables Table 2.1: Geologica
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Chapter 1 Introduction 1.1 Backgrou
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Figure 1.1: Location of Sudbury and
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Chapter 2 Geological Assessment of
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ack breccia and sediments later dep
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Murray Fault, the principal fault o
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2.2 Local Geology of Creighton Mine
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B West East B’ Figure 2.4B: Longi
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Table 2.2: Fault systems within the
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Table 2.3: Summary of Fault Charact
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Figure 2.6: (A) Damage to shotcrete
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Figure 2.7: (A) The 1290 Shear Zone
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Figure 2.8: Images of (A) the 400-E
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Figure 2.9: (A) Photograph of the c
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Figure 2.10 (A) Shear foliation, in
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Figure 2.11: Thin sections of the F
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(Fig. 2.12B). Reduction of quartz g
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2.3.11 Late-Stage Fractures The you
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overprinting (Cochrane, 1991; Couls
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Table 2.4: Summary of Proterozoic t
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Both of these inferred stress direc
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are, at this time, in the process o
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Microseismic events of this subset
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3.2.1.2 Seismic Energy (E o ) and S
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3.2.1.4 Stress Parameters Stress pa
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located events were removed from cl
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Figure 3.7: Detected seismicity cor
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Table 3.1: Event characteristics in
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Table 3.3: Summary of relevant para
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) Damage Zone The rock mass in the
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quadrants of dilatation and compres
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Figure 3.12: Lower hemisphere equal
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mechanism shows that over 57% of th
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Figure 3.16: Classification of prin
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Figure 3.18: Contoured P-axis, B-ax
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Figure 3.20: Distribution of double
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This parameter reflects the magnitu
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Figure 3.23: Preliminary stress inv
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Figure 3.25: Equal area stereonet s
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Figure 3.27: (A) Maximum principal
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4.2 Numerical Methods Phase 2 and U
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Stress-strain relationships are use
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Rock mass failure is governed by th
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Figure 4.5: (A) Model for tectonic
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The zero cohesion and low friction
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Figure 4.9: Model of yielding for C
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Figure 4.11: Model of differential
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Figure 4.14: Model of maximum stres
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stress field model. There is little
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clustering are indications of rock
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Figure 4.23: Contoured domains of s
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Figure 4.24: Fracture initiation th
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seismic Cluster 1, which correspond
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contains energetic events and is no
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preferentially oriented fracture pl
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methodologies employed are of value
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References Alcott, J. M., Kaiser, P
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Galkin, V., Mungall, J. (2005). Str
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Mungall, J. E., & Hanley, J. J. (20
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Appendix A Geological Maps and Samp
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A.2 Level Plans with Sample Locatio
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Figure A3: 7400 Level, modified for
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Figure A5: 7680 Level, modified for
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Figure A7: 7940 Ramp, modified from
Page 143 and 144: MICROSEISMIC EVENTS Source Radius A
Page 145 and 146: 2006 Event Frequency with Depth 600
Page 147 and 148: B.2 Spatial Distribution of Seismic
Page 149 and 150: Figure B11: Events between Jan 1, 2
Page 155 and 156: Cluster 1 Source Radius Asp. Radius
Page 157 and 158: Seismic Moment 10.0 9.5 9.0 8.5 8.0
Page 159 and 160: 143 Peak Velocity Parameter -2.5 -2
Page 161 and 162: B.4.2 Temporal Distribution of Clus
Page 163 and 164: 147 Static Stress Drop 5.0 5.5 6.0
Page 165 and 166: B.4.3 Temporal Distribution of Clus
Page 167 and 168: 151 Static Stress Drop 4.0 4.5 5.0
Page 169 and 170: Frequency-Magnitude Relation for Cl
Page 171 and 172: P-axis B-axis T-axis 155 Fault Plan
Page 173 and 174: P-axis B-axis T-axis Fault Plane 1
Page 179 and 180: D.1.1: Case 1 Models Figure D1: Cas
Page 181 and 182: Figure D3: Case 1, elastic models s
Page 183 and 184: A B C D Figure D5: Case 1, plastic
Page 185 and 186: A B C D Figure D7: Case 1, plastic
Page 187 and 188: D.1.2: Case 2 Models A B C D Figure
Page 189 and 190: D.1.3: Case 3 Models A B C Figure D
Page 191 and 192: D1.4 Tectonic Loading Models Figure
Page 193: D.2 Discussion of Phase 2 Models El
Page 197 and 198: Figure D17 (A) Elastic model showin
Page 199 and 200: Figure D19 (A) Elastic model showin
Page 201 and 202: • Similar damage zones surroundin
Page 203 and 204: ; ;================================
Page 205 and 206: change jmat=1 range 0,1564.64 0,156
Page 207 and 208: crack (845.579,718.676) (787.063,57
Page 209 and 210: ;===plum=== crack (0,355.2371429) (
Page 211 and 212: crack (866.14,726.44) (838.2,737.61
Page 213 and 214: crack (838.2,737.616) (815.848,771.
Page 215 and 216: crack (815.848,771.144) (815.848,78
Page 217 and 218: ;===== define sub block ===========
Page 219 and 220: E.9 S3:S1 Model for fracture reacti
Page 221 and 222: yval= abs(z_syy(zi)) xyval= abs(z_s
Page 223 and 224: and rearranged to , (Equation F4) .
Page 225: Such that , (Equation F19) I is the
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title of the thesis - Department of Geology - Queen's University

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