DRILLING AND BLASTING OF ROCKS

Transcription

1 DRILLING AND BLASTING OF ROCKS CARLOS LOPEZ JIMENO Project Director for EPM, S.A 4f-- EMILIO LOPEZ JIMENO FRANCISCO JAVIER AYALA CARCEDO Project Director for ITGE Translated by YVONNE VISSER DE RAMIRO vi A. A. B ALKEMA / ROTTERDAM / BROOKFIELD / 1995

2 Contents Us. - FOREWORD IX 4 ROTARY DRILLING WITH ROLLING TRIGONE BITS 48 PREFACE XI 4.1 Introduction Mounting and propulsion systems 48 ACKNOWLEDGEMENTS xni 4.3 Power sources Rotation systems 49 1 ROCK DRILLING METHODS I 4.5 Pulldown/hoisting systems 50 LI Introduction I 4.6 Mast and pipe changer Types of drilling operations used in rock 4.7 Control cabin 52 breakage I 4.8 System for flushing drill cuttings Fields of application for the different drilling 4.9 Drill string 53 methods Auxiliary elements Classification of the rocks and their 4.11 Operative practice. Drilling parameters 56 principal physical properties Penetration rate Calculation of drilling costs ROTARY PERCUSSIVE DRILLING Introduction 8 5 ROLLING CONE ROCK BITS Fundamentals of rotary percussive drilling Rolling cone rock bits Top hammer drilling Major components and design features Drilling with down the hole hammer The metallurgy of rolling cone rock bits Advance systems Types of rolling cone bits Mounting systems Bit type selection Dust collectors Effects of the operating parameters on the 2.8 Inclination instruments 30 rolling cone bits Penetration rate Nozzle selection Average penetration rate Evaluation of dull rolling cones Calculation of drilling costs Example of roller tricone bit selection IDAC Codes ROTARY PERCUSSIVE DRILLING ACCESSORIES 36 6 ROTARY DRILLING WITH CUTTING 3.1 Introduction 36 ACTION Types of threads Introduction Shank adaptors Fundamentals of drilling with cutting action Drill steel Flushing of drill cuttings Couplings Cutting tools Drill bits Calculation of the necessary drilling accessories 43 7 SPECIAL DRILLING METHODS AND 3.8 Care and maintenance of the bits 43 MOUNTING SYSTEMS Care and maintenance of drill steel Introduction Guide for identifying accessory failure 7.2 Drilling through overburden 77 and its causes Shaft sinking Raise driving 80 V

3 VI Contents 7.5 Jet piercing JH 7.6 Water-jet drilling Drilling ornamental rock COMPRESSORS Introduction S7 8.2 Types of compressors Drive m 8.4 Auxiliary elements Calculating pressure drops THERMOCHEMISTRY OE EXPLOSIVES AND THE DETONATION PROCESS Introduction Deflagration and detonation Detonation process of an explosive Thermochemistry of the explosives Heat of explosion Oxygen balance Volume of explosion Minimum energy available Temperature of the explosion Pressure of the explosion PROPERTIES OF EXPLOSIVES Introduction Strength and energy Detonation velocity Density Detonation pressure Stability Water resistance Sensitivity Detonation transmission Desensitization 104 * Resistance to low temperatures Eumes INDUSTRIAL EXPLOSIVES Introduction Dry blasting agents Slurries Emulsions III 11.5 Heavy ANFO Gelatin dynamites Granular dynamite Permissible explosives Blackpowders Two-component explosives Explosives commercialized in Spain EXPLOSIVE SELECTION CRITERIA Introduction Explosive cost Charge diameter Rock characteristics Volume of rock to be blasted Atmospheric conditions Presence of water Environmental problems Fumes Safety conditions Explosive atmospheres Supply problems BLASTING ACCESSORIES Introduction Nonelectric initiation systems Electric initiation systems Sources of energy Other accessories INITIATION AND PRIMING SYSTEMS Introduction Priming and boostering bulk ANEO-type blasting agents 136 J 14.3 Priming cartridge ANFO type blasting agents Priming pumped or poured slurry and emulsion blasting agents Priming cartridged watergel and emulsion blasting agents Location of primers Priming conventional cartridged explosives MECHANIZED SYSTEMS EOR CHARGING AND DEWATERING BLASTHOLES Introduction Mechanized blasthole charging systems Blasthole dewatering systems MECHANISMS OF ROCK BREAKAGE Introduction Rock breakage mechanisms Transmission of the strain wave through the rock mass Energetic yield of the blastings ROCK AND ROCK MASS PROPERTIES AND THEIR INFLUENCE ON THE RESULTS OF BLASTING Introduction Rock properties Properties of the rock mass

4 Contents Vll 18 CHARAC I'bRIZATION OF THE ROCK 213 Trench blastine 208 ^ X * X X WX IWX X x/xxxo xxxx^^ MASSES FOR BLAST DESIGNING Ramn hlashnp ('sinking ciio 210 'i 18.1 Introduction 167 ^ L.~ IXUlllL/ L/lxXoLlxl^ lollln.lllg 91 S RlfiQtincT Tor orniinh l/*vf*lin< Diamond drilling with core recovery and 91 (S RlflstiriQs "for fniinhations 213 ~r geomechanic testing 10/ zi. / iviini-noic Diasung 214 ; Characteristics of the joint systems , L.o 8 LPrphla<;Hnp<! I djiaaiiiigo 215. ; Seismic survey Geophysical techniques to obtain rock mass data Bl A STING FOR TUNNELS AND DRIFTS 217 L f\j Ul_^xVO 1111VJ 1 A71X 1 \_/1111 L^l_(xJ ILL ^1X11 1 \J 18.6 Logging of production blastholes Introduction 217 X XXI LX V/\X XXV/XM 18.7 Characterization of the rock mass during 22 2 Advance svstems 217 blasthole drilling 171. L. I XXX V LXXX^Xp' Cf T OX^^'XXXkX 99 9 Rlactino nattpmq for tiinnplq The attempt to correlate drilling indexes 99 4 Ti/npc l y p c s KJL /ifpiifc CUld aliu QTiH CalLUiallUll pialfiil Qtinn Ul irf LliC tfip hlactc Ulaotd 219 with the blasting design parameters O ^ IZ/i^UipiUCUL Rniiinmpnt ifr\r U l lucuklllg miirlcinfr UUL nut Hrillino Uillllllg 18.9 System of drilling data management in 230 actual time 177 R XXTPfCXtm^C III ixciclcliccis I / O 9T 4.D on/xr ^HAFT 1 o^tnicinri i i i r v i i i v j / AND x i i i 7 rrat8f w x i o i j 171X1 DRTVING V l i i x j CONTROLLABLE PARAMETERS OF 9T 1 TntrnHiirtioti 231 BLASTING 1701 ly 23.2 XM7> 1 Shaft lllll v/vxux.'lla/ll sinking Introduction ly 23.3 Raise driving Blasthole diameter Height of bench 181 l O Blasthole inclination UNDERGROUND PRODUC l ION BLASTING 1 O Stemming length 189 IN MINING AND CIVIL ENGINEERING Subdrilling Introduction Burden and spacing 18T 24.2 Crater retreat method 239 loj 19.8 Blasthole patterns 18T 24.3 Longhole method Geometry of the free face Sublevel stoping with blastholes in fan Size and shape of the blast 18S pattern O J Available expansion volume Room and pillar mining 248 ou Charge configuration 1 a/t 24.6 Cut and fill mining Decoupling of the charges 1(30 1 ou Underground chambers in civil Explosives 1 l O 87 / engineering projects Distribution of explosives in the 251 blastholes o / Powder factor CONTOUR BLASTING 252 i Initiation and priming 1 oo Introduction 252, Delay timing and initiation sequences 1 88 oo 25.2 Mechanisms responsable for overbreak Influence of loading equipment on the 25.3 The theory of contour blasting 253 design of the blasts 1 ao 25.4 Types of contour blasts 254 toy Specific drilling 1 ao 25.5 The parameters that intervene in a Blasthole deviation lo!7 ion contour blasting Tendencies in the field of contour blasting y\j 25.7 Evaluation of the results BENCH BLASTING Example oo 20.1 Introduction Extraction of ornamental rock with 20.2 Small diameter bench blasting 191 contour blasting Large diameter blasting 1QT J 20.4 Bench blasting with horizontal blastholes Rip-rap production blasting UNDERWATER BLASTING Cast blasting Introduction yyj Appendix 1: Eormulas to calculate bench 26.2 Methods of execution 272 blasting patterns Calculations for charges and drilling ZUJ patterns Charging the blastholes and priming 21 BLASTING IN OTHER SUREACE systems 275 OPERATIONS Types of explosives Introduction Environmental effects associated with 21.2 Excavations for highways and railways 205 underwater blastings 276

5 VIII Contents 26.7 Shaped or concussion charges OPTIMIZING COSTS OE FRAGMENTATION 279 WITH DRILLING AND BLAS1ING 323 ooo 32.1 Introduction 323 INITIATION SEQUENCE AND DELAY 32.2 Economical aspects of drilling and OO 1 1/11 TIMING blasting 323 T-)C 27.1 Introduction oo Model for determining cost optimization 325 OO Single-row delayed blast 32.4 Predicting the fragmentation 326 /i/i c r> u. X* 1 *..x.»-xj.-.i Multi-row sequenced bench blastings Probabilistic analysis optimization model 331 /^^^ 4 T"\ 111.' f 1 XI Bench blasting sequences for underground stopes T T A MTA \ /TDD A XT/AMC A TD DT A C T A X T H 27.5 Delay timings 285 O OO 33 LAND TTTDTD VlBRAflONS, X/TATTDdT AIR BLAS 1 AND 27.6 Underground blasts m tunnels and dnfts O OO THEIR CON 1ROL Introduction o o o r\ X 1 ' 1 74? X ' i_ X 33.2 Parameters which affect vibration 1*11 T X X T T Xrxix> V V Tx^"vx"i x-\ X X /in 1 T1 x*i/ix Tx rxi/i EVALUATION OE BLAST RESULTS 290 characteristics 333 i n 28.1 Introduction Charactenstics ot ground vibrations /I ii /I 1 «1 11' I* tt O O A A * L 1... X _ a, aa aaa. -a. - ' a. 4. ^ aa aa Fragmentation and swelling of the 33.4 Air blast charactenstics a a ' C 1" 1 muckpile Instrumentation for recording and A /I ^ ^ s i->l 1 *1 *.1*1. analyzing vibrations and air blast Geometry of the muckpile, its height 1 ^ ' and displacement Calculators of propogation laws for land 28.4 Condition of the remaining mass 294 and air vibrations * 7 '1.' J 1 A Analysis of the bench floor Studies of vibration and air blast Boulders in the muckpile Damage prevention cntena tor buildings cr\ /I1-1 ^1 X T'l * I ' l l. 1 1 (1 T*" 77 x_ IT *l_ -.X* 1 X 28.7 Vibrations and airblast Effects of vibrations and air blast on /I H /- XI /II /* Profiles of underground excavations 296 people Conclusions Effects of vibrations on rock masses 358 on^ Effect of vibrations on freshly poured 296 concrete n j x ' C i _ " 1 SECONDARY FRAGMENTATION AND Recommendations for reducing ground HXIX'l^'IX X X XIX X xi rxix'x T 71 XI SPECIAL BLASTINGS 299 vibration and air blast levels Introduction Pop shooting Xi * 1.1 A ' n T rxi 71 7*1 X 7 71 X V TX1 Pill XX"»XX ^ If ^1 1 71X 29.3 Secondary breakage by mechanical FLYROCKS AND THEIR CONTROL means and special methods Introduction 366 /I A /I 1X I.1 7 /I Special blastings Models to calculate the throw of flyrock X O Covenngs A 4 XI I x * 7 xl 1 X1T A X TX T T X T 71 XnX X XI X X T 71 XI X X 71XI X-X XI XX X X ^ T Recommendations for carrying out bench PLANNING THE WORK OF DRILLING blastings 370 AND BLASTING \J 30.1 Introduction /I 7\ y1 XI.1.1 n a 1 T O C 305 /I ^ 71 X IPWIX t 1 7in X 71X TXI XI71 XI7-1XI XIXI XX X XI T7n X 1 TX Factors that have influence on the 35 SAFETY MEASURES EOR DRILLING AND XIX X ntiti T7~< TITIXTI A T'T71'A.TO n 1 planning of drillling and blasting 305 BLASTING OPERATIONS Planning the stages of excavation Introduction Blasthole drilling C 1 XI1 375 STRUCTURE AND BUILDING 35.3 Blastings 381 DEMOLITION Introduction 312 CONVERSION FACTORS Drilling diameters and types of explosives Demolition of structural elements 313 GENERAL INFORMATION, WEIGHT OF 31.4 Demolition of structures 316 MATERIALS Demolition of buildings Demolition of steel structures 322 GLOSSARY SUBJECT INDEX 389 dt