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Rock Excavation University of rizona Mining and Geological Engineering 415 - Rock Excavation Course Notes – Spring 2003 Module 1-5 Compiled by: Dr. Sean Dessureault MGE 415 – Rock Excavation 2004 Table of Contents MODULE 1: INTRODUCTION ......................................................................................................... 1 1.1 INTRODUCTION .............................................................................................................................. 1 ADDITIONAL RESOURCES I .................................................................................................................. 1 1.2 GEOLOGICAL PROPERTIES IN ROCK EXCAVATION ......................................................................... 1 1.2.1 Minerals and Rocks .................................................................................................................. 1 1.2.2 The properties of rocks ............................................................................................................. 3 1.2.3 Rock classification.................................................................................................................... 6 1.2.4 Rock Strength............................................................................................................................ 8 ADDITIONAL RESOURCES II............................................................................................................... 16 1.3 ROCK BREAKING PROCESSES....................................................................................................... 16 1.3.1 Primary................................................................................................................................... 17 1.3.2 Secondary ............................................................................................................................... 20 1.3.3 Tertiary................................................................................................................................... 21 1.3.4 Miscellaneous......................................................................................................................... 23 ADDITIONAL RESOURCES III ............................................................................................................. 24 MODULE 2: DRILLING AND BLASTING COMPONENTS......................................................... 1 2.1 DRILLING MECHANISMS ................................................................................................................ 1 2.1.1 Percussive Drilling................................................................................................................... 2 ADDITIONAL RESOURCES IV ............................................................................................................... 5 2.1.2 Rotary Drilling......................................................................................................................... 6 ADDITIONAL RESOURCES V............................................................................................................... 28 2.2 DRILLING EQUIPMENT.................................................................................................................. 28 ADDITIONAL RESOURCES VI ............................................................................................................. 28 2.3 EXPLOSIVES INTRODUCTION........................................................................................................ 28 2.3.1 Detonation Theory.................................................................................................................. 28 2.3.2 Comparative Explosive Properties ......................................................................................... 33 2.3.3 Thermochemistry of Explosives and the Detonation Reaction. .............................................. 38 ADDITIONAL RESOURCES VII............................................................................................................ 39 2.4 EXPLOSIVE PRODUCTS................................................................................................................. 40 2.4.1 History of Explosives.............................................................................................................. 40 2.4.2 Energetic material .................................................................................................................. 42 2.4.3 Explosives and Propellants..................................................................................................... 43 2.4.4 Single Molecule and Composite Explosives ........................................................................... 43 2.4.5 Primary, Secondary, and Tertiary explosives......................................................................... 46 2.4.6 Commercial Explosives .......................................................................................................... 46 2.4.7 Nitroglycerin-based Explosives .............................................................................................. 47 2.4.8 Dry Blasting Agents................................................................................................................ 48 2.4.9 Wet Blasting Agents................................................................................................................ 49 2.4.10 Primers and Boosters-........................................................................................................ 52 2.4.11 Initiators and Initiation Systems......................................................................................... 52 2.4.12 Electric Caps...................................................................................................................... 52 2.4.13 Non-electric caps ...............................................................................................................53 2.4.14 Electronic Detonators ........................................................................................................ 54 2.4.15 Detonating cord .................................................................................................................54 ADDITIONAL RESOURCES VIII .......................................................................................................... 55 Dessureault 1/14/2004 i MGE 415 – Rock Excavation 2004 MODULE 3: BLAST DESIGN.......................................................................................................... 56 BLAST DESIGN BASICS ............................................................................................................................. 56 System Approach ................................................................................................................................. 56 Idealized fragmentation curves............................................................................................................ 59 Preliminary guidelines for blast layout ............................................................................................... 62 Ratios for initial design ....................................................................................................................... 70 Powder Factor..................................................................................................................................... 73 Determination of KB............................................................................................................................. 74 Effects to pattern design in changing explosives ................................................................................. 76 Effects to pattern design in changing rock types ................................................................................. 77 Numerical Examples............................................................................................................................ 78 Stemming & Decking ........................................................................................................................... 80 Concluding Notes on D, B, and PF ..................................................................................................... 82 ADDITIONAL RESOURCES IX ............................................................................................................. 83 GEOLOGICAL IMPACTS ON BLAST DESIGN................................................................................................ 83 Rock Properties ................................................................................................................................... 83 Structure .............................................................................................................................................. 85 ADDITIONAL RESOURCES X............................................................................................................... 92 PATTERNS AND SEQUENCING.................................................................................................................... 93 Effective Burden and Spacing.............................................................................................................. 94 Designing the Timing........................................................................................................................... 96 Generalized Timing ............................................................................................................................. 97 Skipping a Period
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