Rock Blasting: Effects and Operations
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Summary
This book is a unique supplement to contemporary scientific literature on rock blasting technology. It encapsulates theoretical and practical aspects of drilling and blasting techniques used in both surface and subterranean excavations connected with civil as well as mining activities. Case studies are presented to illustrate correlations between theoretical calculations and empirical findings. It also summarizes the results of research carried out by the Blasting Department of the Central Mining Research Institute since its inception in the year 1970. It contains fifteen extensive chapters covering statistical methods, design parameters, rock breakage mechanism, structural damage, fragmentation, emerging techniques, surface and sub-surface blasting methodologies, safety and environmental aspects, explosive characteristics and modern initiating devices.
Table of Contents
CONTENTS
Preface
Chapter-1: Statistical Approaches and Useful Mathematical Formulae 1-17
- Introduction 01
- Statistical Analysis of Field Data 01
- Statistical Method and Their Physical Interpretations 02
- Important Mathematical Formulae 14
- Summary 16
Chapter-2: Terms and Parameters Influencing Mine and Ground
Excavations 18-50
2.1 Introduction 18
2.2 Parameters Related to Explosive Properties 20
2.3 Parameters Related to Geomechanical Properties of Rock Mass 21
2.4 Parameters Related to Blast Geometry 22
2.5 Parameters Related to Initiation Pattern 22
2.6 Terms and Parameters Associated with Drilling and Blasting 22
Chapter-3: Detonation Principle and Rock Breakage Mechanism 51-60
3.1 Introduction 51
3.2 Basic Introduction of High and Low Explosives 51
3.3 Principle of Detonation and Breakage 53
3.4 Rock Breakage 54
3.5 Formation of Seismic Waves 56
3.6 Shock Energy 57
3.7 Gas Energy 58
3.8 Fracturing by Release of Load 58
3.9 Gas Expansion 59
3.10 Reflection Breakage 60
Chapter-4: Strength of Explosives – Theoretical Derivation and 61-76
Laboratory Determinations
4.1 Introduction 61
4.2 Strength of Explosives 61
4.2 Laboratory Determination of Explosive Energy 61
4.3 Theoretical Determination of Energy Release 68
4.4 Calculation of Heat of Explosion 69
4.5 Ideal Mixture of ANFO and Fuel Oil 71
4.6 Partition of Explosive Energy 72
Chapter-5: Prediction, Control and Damage thresholds of
Ground Vibration from Opencast Blasting 77-105
5.1 Introduction 77
5.2 Generation and Propagation of Ground Vibration
from Opencast Blasting 78
5.3 Commonly Used Blast Vibration Predictors 79
5.4 Geometrical Spreading 81
5.5 Inelastic Attenuation or Damping 82
5.6 Inelastic Attenuation Factor 82
5.7 Values of Empirical Constants for Various Rock Masses 83
5.8 CMRI Predictor Equation 87
5.9 Mixed Analytical-Empirical Model 91
5.10 Confidence Envelopes 94
5.11 Threshold Values of Ground Vibrations for Structures 94
5.12 Conclusions 101
Chapter-6: Structural Response and Damage Criteria for
Safety of Surface Structures 106-136
6.1 Introduction 106
6.2 Damage Prevention Criteria for Structures 107
6.3 Formation of low frequency vibrations 109
6.4 Damage Studies Through Test Structures 113
6.5 Field Studies on Residential and Industrial Structures 127
6.6 Effect of Repeated Blasting 132
6.7 Vibration Response of Restrained Pipelines 134
6.8 Discussions 134
6.9 Conclusions 135
Chapter-7: Influence of Blasting on Surface Structures
and Underground Workings 137-169
- Surface Blasting – Underground Effects 137
7.1.1 Introduction 137
7.1.2 Blast Vibrations 138
7.1.3 Effect of Rock Quality 138
7.1.4 Damage Classification 141
7.1.5 Blast Damage Index (BDI) 142
7.1.6 Case Studies 143
7.2 Underground Blasting – Surface Effects 152
7.2.1 Introduction 152
7.2.2 Problems Related to Underground Blasting 152
7.2.3 Factors Affecting Ground Vibration 152
7.2.4 Structural Response 155
7.2.5 Findings of Investigation 158
7.3 Underground Blasting – Underground Effects 159
7.3.1 Introduction 159
7.3.2 Effect of Vibration on Parting between
Two Contiguous Seam Workings 159
7.3.3 Comparative Study of Effect of Blasting with Machine
Cut, Auger Holes and Blasting off the Solid 163
7.3.4 Air Overpressures in the Underground Workings 165
7.3.5 Zone of Disturbance Caused by Blasting 165
7.4 Conclusions 166
Chapter- 8: Blast Monitoring and Characterization 170-179
8.1 Introduction 170
8.2 Sensor Setting 170
8.3 Sensor Types 171
8.4 What Kind of Sensor should be used? 172
8.5 Richter Scale versus PPV 173
8.6 Approach of Tracking Blast Vibrations 175
8.7 Peak Particle Velocity versus Strain 177
8.8 Low Frequency Response 177
8.9 Summary Analysis of Vibration Risks in U/G Works 178
Chapter-9: Ringhole Blasting in Coal in Blasting Gallery Panels 180-203
9.1 Introduction 180
9.2 General Description 180
9.3 Prerequisites of BG 181
9.4 Conditions before Commencement of Extraction 181
9.5 Advantages of BG method 181
- Limitations 182
9.7 Drilling and Blasting Practices in BG Method 182
9.8 Case Studies 186
9.9 Fragmentation Study at GDK-10 Incline Mine 186
9.10 Case Study at GDK-8 Incline Mine 191
9.11 Energy-based Vibration Predictor Equations 193
9.12 Critical Convergence 197
9.13 Prediction of Roof Fall 198
9.14 Blast Damage Index (BDI) 199
9.15 Suggested Design Patterns and Guidelines 201
9.16 Conclusions 202
Chapter-10: Rock Fragmentation and Assessment 204-237
10.1 Introduction 204
10.2 Indian Coal Mining Scenario 204
10.3 Fragmentation Assessment Methods 205
10.4 Results of CMRI Investigations 207
10.5 Charge Factor 208
10.6 Blast Design for Heterogeneous Strata 210
10.7 Fragmentation Prediction Models 212
10.8 Drilling and Blasting Cost Assessment 214
10.9 Case Studies 218
10.10 Fragmentation Cost Assessment 221
10.11 Effect of Initiation Timing 222
10.12 Pattern Constructions and Muckpile Shape 222
10.13 Effects of Fragmentation on Subsystems 227
10.14 Determination of Face Orientation 228
10.15 Design Patterns for Non-coal Deposits 231
10.16 Computer Models of Fragmentation Prediction 231
10.17 Conclusion 234
Chapter-11: Socio-Economic and Environmental Impacts of Blasting 238-254
11.1 Introduction 238
11.2 Human Response to Blast Induced Vibrations 239
11.3 Human Reaction to the Effect of Blasting 240
11.4 Air blast and Associated Annoyance 243
11.5 Flyrock – Occurrence and Control 248
11.6 Blasting in Underground Coal Mines 251
11.7 Blasting Procedures in Hot Holes 252
11.8 Measurement of Dust Clouds 252
11.9 Remedial Measures: General Guidelines 253
Chapter-12: Emerging Blasting Techniques 255-297
12.1 Air-decking Principle 255
12.1.1 Introduction 255
12.1.2 Theory of Air-deck Blasting 256
12.1.3 Breakage Process in Air-deck Blasting 261
12.1.4 Usage of Air-decking in Presplit Blasting 263
12.1.5 Conclusions 263
12.2 Baby-Decking Technique 264
12.2.1 Introduction 264
12.2.2 Scientific Identification of the Problem 264
12.2.3 Baby-decking 266
12.2.4 Conclusion 267
12.3 Segregation Blasting 268
12.3.1 Introduction 268
12.3.2 Mechanism of Segregation Blasting 268
12.3.3 Air-Drag 269
12.3.4 Law of Resistance 270
12.3.5 Correction for Air-drag 270
12.3.6 Case study 271
12.3.7 Experimental trials 272
12.3.8 Conclusion 273
12.4 Additives in ANFO for Optimum Blasting 274
12.4.1 Introduction 274
12.4.2 Scientific Background 274
12.4.3 Detonation Velocity and Pressure of ANFO/Sawdust Mixture 275
12.4.4 Properties and Chemical Reaction of ANFO/Sawdust Mixture 276
12.4.5 Procedure of Mixing Sawdust with ANFO 277
12.4.6 Experimental Blasts 277
12.4.7 Observation 278
12.4.8 Conclusions 279
12.5 Induced Caving by Blasting 280
12.5.1. Introduction 280
12.5.2 What is Induced Blasting? 280
12.5.3 Results of Strata and Gas Monitoring 281
12.5.4 Design Patterns 281
12.5.5 Fragment Size Analysis 281
12.5.6 Software Developed 285
12.5.7 Conclusion 285
12.6. Blast Closure 286
12.6.1 Introduction 286
12.6.2 Reasons for Closure 287
12.6.3 Closure Planning 287
12.6.4 Methods of Closure 288
12.6.5 Conclusion 290
12.7 Demolition Blasting 291
12.7.1 Introduction 291
12.7.2 Basic Design Patterns 291
12.7.3 Demolition of Piers 291
12.7.4 Conclusion 294
Chapter-13: Rock Excavation by Non-explosive Methods 298-313
13.1 Introduction 298
13.2 Acconex: Non-Explosive Demolishing Compound 298
13.3 Capsuled Compressed Gas Cartridges 303
13.4 Mechanical Methods 304
13.5 Electrical Methods 305
13.6 Liquid Jet Systems 305
13.7 Expansive Mortar 305
13.8 Surface Miner 305
13.9 Penetrating Cone Fracture 308
13.10 Plasma Blasting 311
13.11 Conclusions 312
Chapter-14: Blasting in Surface and Subsurface Hard Rocks 314-344
14.1 Blasting in Dimension Stone Quarrying 314
14.1.1 Introduction 314
14.1.2 Traditional Methods 314
14.1.3 Presplitting Mechanism 315
14.1.4 Dimension Stone Quarries 316
14.1.5 Conclusion 317
14.2 Blasting in Himalayan Rocks 317
14.2.1 Introduction 317
14.2.2 Rock-Geologic Parameters 318
14.2.3 Effects of Blast Vibration on Rock Masses and Slopes 319
14.2.4 Blast Pattern 320
14.2.5 Ground Vibration Monitoring 320
14.2 6 Vibrations from Non-Blasting Events 320
14.2.7 Blast Design Patterns for Safe and Optimal Excavation 321
14.2.8 Drilling Pattern 322
14.2.9 Charge Factor and Initiation Sequences 323
14.2.10 Boulder Blasting 324
14.2.11 Concluding Remarks and Guidelines 324
14.3 Slope Failure Due to Unscientific Quarrying 329
14.3.1 South Hlimen Quarry 329
14.3.2 Conclusion 329
14.4 Underground Metal Mining 331
14.4.1 Introduction 331
14.4.2 Mining Methods with Vertical Crater Retreat (VCR) Stoping 331
14.4.3 Large Diameter Long Blastholes ‘LBH’ (115 mm and above) 331
14.4.4 Relationship Between Length of Charge and Diameter 332
14.4.5 Intermediate Stemming 332
14.4.6 Initiation Sequence 333
14.4.7 Case Study (Khetri Copper Mine) 333
14.4.8 Conclusions 341
14.5 Underwater Blasting 342
Chapter-15: Performance Evaluation of Explosives and Accessories 345-359
15.1 Performance Test of Explosives 345
15.1.1 Introduction 345
15.1.2 Explosive Ratings 345
15.1.3 Mixture of Ammonium Nitrate and Fuel Oil 348
15.1.4 Conclusion 348
15.2 Scattering in Delay Timing of Delay Detonator 348
15.2.1 Introduction 348
15.2.2 Winzer Index 349
15.2.3 Estimation of Initiation Gap 350
15.2.4 Thermal Behaviour of Commercial Explosives 351
15.2.5 Conclusions 351
15.3 Non-electric Initiating Devices 352
15.3.1 Introduction 352
15.3.2 Raydet DTH and TLD 352
15.3.3 EXEL System 353
15.3.4 Study of Component Scatter 355
15.3.5 Probability Calculations 355
15.3.6 Observations 356
15.3.7 Conclusion 357
Conversion Factors 360
Index 361-362
Author Bio(s)
Dr. P. Pal Roy is a Deputy Director and Scientist-in-Charge of the Blasting Department of the Central Mining Research Institute, Dhanbad, India. He is the inventor of CMRI Vibration Predictor Equation, Burden-Spacing Equations and Fragmentation Analyzing Scale besides establishing a number of CMRI standard and guidelines related to blasting methodology and applications. Recently, he has been associated with two S&T Projects funded by the Ministry of Coal and Mines and Defence Terrain Research laboratory, DRDO, Government of India.
