1st Edition

Rock Blasting Effects and Operations

By Pijush Pal Roy Copyright 2005
    360 Pages
    by CRC Press

    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.

    Preface

    1 Statistical Approaches and Useful Mathematical Formulae
    1.1 Introduction
    1.2 Statistical Analysis of Field Data
    1.3 Statistical Method and Their Physical Interpretations
    1.4 Important Mathematical Formulae
    1.5 Summary

    2 Terms and Parameters Influencing Mine and Ground Excavations
    2.1 Introduction
    2.2 Parameters Related to Explosive Properties
    2.3 Parameters Related to Geomechanical Properties of Rock Mass
    2.4 Parameters Related to Blast Geometry
    2.5 Parameters Related to Initiation Pattern
    2.6 Terms and Parameters Associated with Drilling and Blasting

    3 Detonation Principle and Rock Breakage Mechanism
    3.1 Introduction
    3.2 Basic Introduction of High and Low Explosives
    3.3 Principle of Detonation and Breakage
    3.4 Rock Breakage
    3.5 Formation of Seismic Waves
    3.6 Shock Energy
    3.7 Gas Energy
    3.8 Fracturing by Release of Load
    3.9 Gas Expansion
    3.10 Reflection Breakage

    4 Strength of Explosives – Theoretical Derivation and Laboratory Determinations
    4.1 Introduction
    4.2 Strength of Explosives
    4.2 Laboratory Determination of Explosive Energy
    4.3 Theoretical Determination of Energy Release
    4.4 Calculation of Heat of Explosion
    4.5 Ideal Mixture of ANFO and Fuel Oil
    4.6 Partition of Explosive Energy

    5 Prediction, Control and Damage thresholds of Ground Vibration from Opencast Blasting
    5.1 Introduction
    5.2 Generation and Propagation of Ground Vibration from Opencast Blasting
    5.3 Commonly Used Blast Vibration Predictors
    5.4 Geometrical Spreading
    5.5 Inelastic Attenuation or Damping
    5.6 Inelastic Attenuation Factor
    5.7 Values of Empirical Constants for Various Rock Masses
    5.8 CMRI Predictor Equation
    5.9 Mixed Analytical-Empirical Model
    5.10 Confidence Envelopes
    5.11 Threshold Values of Ground Vibrations for Structures
    5.12 Conclusions

    6 Structural Response and Damage Criteria for Safety of Surface Structures
    6.1 Introduction
    6.2 Damage Prevention Criteria for Structures
    6.3 Formation of low frequency vibrations
    6.4 Damage Studies Through Test Structures
    6.5 Field Studies on Residential and Industrial Structures
    6.6 Effect of Repeated Blasting
    6.7 Vibration Response of Restrained Pipelines
    6.8 Discussions
    6.9 Conclusions

    7 Influence of Blasting on Surface Structures and Underground Workings
    7.1 Surface Blasting – Underground Effects
    7.1.1 Introduction
    7.1.2 Blast Vibrations
    7.1.3 Effect of Rock Quality
    7.1.4 Damage Classification
    7.1.5 Blast Damage Index (BDI)
    7.1.6 Case Studies
    7.2 Underground Blasting – Surface Effects
    7.2.1 Introduction
    7.2.2 Problems Related to Underground Blasting
    7.2.3 Factors Affecting Ground Vibration
    7.2.4 Structural Response
    7.2.5 Findings of Investigation
    7.3 Underground Blasting – Underground Effects
    7.3.1 Introduction
    7.3.2 Effect of Vibration on Parting between Two Contiguous Seam Workings
    7.3.3 Comparative Study of Effect of Blasting with Machine Cut, Auger Holes and Blasting off the Solid
    7.3.4 Air Overpressures in the Underground Workings
    7.3.5 Zone of Disturbance Caused by Blasting
    7.4 Conclusions

    8 Blast Monitoring and Characterization
    8.1 Introduction
    8.2 Sensor Setting
    8.3 Sensor Types
    8.4 What Kind of Sensor should be used?
    8.5 Richter Scale versus PPV
    8.6 Approach of Tracking Blast Vibrations
    8.7 Peak Particle Velocity versus Strain
    8.8 Low Frequency Response
    8.9 Summary Analysis of Vibration Risks in U/G Works

    9 Ringhole Blasting in Coal in Blasting Gallery Panels
    9.1 Introduction
    9.2 General Description
    9.3 Prerequisites of BG
    9.4 Conditions before Commencement of Extraction
    9.5 Advantages of BG method
    9.6 Limitations
    9.7 Drilling and Blasting Practices in BG Method
    9.8 Case Studies
    9.9 Fragmentation Study at GDK-10 Incline Mine
    9.10 Case Study at GDK-8 Incline Mine
    9.11 Energy-based Vibration Predictor Equations
    9.12 Critical Convergence
    9.13 Prediction of Roof Fall
    9.14 Blast Damage Index (BDI)
    9.15 Suggested Design Patterns and Guidelines
    9.16 Conclusions

    10 Rock Fragmentation and Assessment
    10.1 Introduction
    10.2 Indian Coal Mining Scenario
    10.3 Fragmentation Assessment Methods
    10.4 Results of CMRI Investigations
    10.5 Charge Factor
    10.6 Blast Design for Heterogeneous Strata
    10.7 Fragmentation Prediction Models
    10.8 Drilling and Blasting Cost Assessment
    10.9 Case Studies
    10.10 Fragmentation Cost Assessment
    10.11 Effect of Initiation Timing
    10.12 Pattern Constructions and Muckpile Shape
    10.13 Effects of Fragmentation on Subsystems
    10.14 Determination of Face Orientation
    10.15 Design Patterns for Non-coal Deposits
    10.16 Computer Models of Fragmentation Prediction
    10.17 Conclusion

    11 Socio-Economic and Environmental Impacts of Blasting
    11.1 Introduction
    11.2 Human Response to Blast Induced Vibrations
    11.3 Human Reaction to the Effect of Blasting
    11.4 Air blast and Associated Annoyance
    11.5 Flyrock – Occurrence and Control
    11.6 Blasting in Underground Coal Mines
    11.7 Blasting Procedures in Hot Holes
    11.8 Measurement of Dust Clouds
    11.9 Remedial Measures: General Guidelines

    12 Emerging Blasting Techniques
    12.1 Air-decking Principle
    12.1.1 Introduction
    12.1.2 Theory of Air-deck Blasting
    12.1.3 Breakage Process in Air-deck Blasting
    12.1.4 Usage of Air-decking in Presplit Blasting
    12.1.5 Conclusions
    12.2 Baby-Decking Technique
    12.2.1 Introduction
    12.2.2 Scientific Identification of the Problem
    12.2.3 Baby-decking
    12.2.4 Conclusion
    12.3 Segregation Blasting
    12.3.1 Introduction
    12.3.2 Mechanism of Segregation Blasting
    12.3.3 Air-Drag
    12.3.4 Law of Resistance
    12.3.5 Correction for Air-drag
    12.3.6 Case study
    12.3.7 Experimental trials
    12.3.8 Conclusion
    12.4 Additives in ANFO for Optimum Blasting
    12.4.1 Introduction
    12.4.2 Scientific Background
    12.4.3 Detonation Velocity and Pressure of ANFO/Sawdust Mixture
    12.4.4 Properties and Chemical Reaction of ANFO/Sawdust Mixture
    12.4.5 Procedure of Mixing Sawdust with ANFO
    12.4.6 Experimental Blasts
    12.4.7 Observation
    12.4.8 Conclusions
    12.5 Induced Caving by Blasting
    12.5.1. Introduction
    12.5.2 What is Induced Blasting?
    12.5.3 Results of Strata and Gas Monitoring
    12.5.4 Design Patterns
    12.5.5 Fragment Size Analysis
    12.5.6 Software Developed
    12.5.7 Conclusion
    12.6. Blast Closure
    12.6.1 Introduction
    12.6.2 Reasons for Closure
    12.6.3 Closure Planning
    12.6.4 Methods of Closure
    12.6.5 Conclusion
    12.7 Demolition Blasting
    12.7.1 Introduction
    12.7.2 Basic Design Patterns
    12.7.3 Demolition of Piers
    12.7.4 Conclusion

    13 Rock Excavation by Non-explosive Methods
    13.1 Introduction
    13.2 Acconex: Non-Explosive Demolishing Compound
    13.3 Capsuled Compressed Gas Cartridges
    13.4 Mechanical Methods
    13.5 Electrical Methods
    13.6 Liquid Jet Systems
    13.7 Expansive Mortar
    13.8 Surface Miner
    13.9 Penetrating Cone Fracture
    13.10 Plasma Blasting
    13.11 Conclusions

    14 Blasting in Surface and Subsurface Hard Rocks
    14.1 Blasting in Dimension Stone Quarrying
    14.1.1 Introduction
    14.1.2 Traditional Methods
    14.1.3 Presplitting Mechanism
    14.1.4 Dimension Stone Quarries
    14.1.5 Conclusion
    14.2 Blasting in Himalayan Rocks
    14.2.1 Introduction
    14.2.2 Rock-Geologic Parameters
    14.2.3 Effects of Blast Vibration on Rock Masses and Slopes
    14.2.4 Blast Pattern
    14.2.5 Ground Vibration Monitoring
    14.2 6 Vibrations from Non-Blasting Events
    14.2.7 Blast Design Patterns for Safe and Optimal Excavation
    14.2.8 Drilling Pattern
    14.2.9 Charge Factor and Initiation Sequences
    14.2.10 Boulder Blasting
    14.2.11 Concluding Remarks and Guidelines
    14.3 Slope Failure Due to Unscientific Quarrying
    14.3.1 South Hlimen Quarry
    14.3.2 Conclusion
    14.4 Underground Metal Mining
    14.4.1 Introduction
    14.4.2 Mining Methods with Vertical Crater Retreat (VCR) Stoping
    14.4.3 Large Diameter Long Blastholes ‘LBH’ (115 mm and above)
    14.4.4 Relationship Between Length of Charge and Diameter
    14.4.5 Intermediate Stemming
    14.4.6 Initiation Sequence
    14.4.7 Case Study (Khetri Copper Mine)
    14.4.8 Conclusions
    14.5 Underwater Blasting

    15 Performance Evaluation of Explosives and Accessories
    15.1 Performance Test of Explosives
    15.1.1 Introduction
    15.1.2 Explosive Ratings
    15.1.3 Mixture of Ammonium Nitrate and Fuel Oil
    15.1.4 Conclusion
    15.2 Scattering in Delay Timing of Delay Detonator
    15.2.1 Introduction
    15.2.2 Winzer Index
    15.2.3 Estimation of Initiation Gap
    15.2.4 Thermal Behaviour of Commercial Explosives
    15.2.5 Conclusions
    15.3 Non-electric Initiating Devices
    15.3.1 Introduction
    15.3.2 Raydet DTH and TLD
    15.3.3 EXEL System
    15.3.4 Study of Component Scatter
    15.3.5 Probability Calculations
    15.3.6 Observations
    15.3.7 Conclusion

    Conversion Factors
    Index

    Biography

    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.