CECW-EG Engineer Manual 1110-2-3800 Department of the Army U.S. Army Corps of Engineers Washington, DC 20314-1000 EM 1110-2-3800 1 March 1972 Engineering and Design SYSTEMATIC DRILLING AND BLASTING FOR SURFACE EXCAVATIONS Distribution Restriction Statement Approved for public release; distribution is unlimited. DEPARTMENT OF THE ARMY EM 1110-2-3800 DAEN-CWE-G Engineer Manual No. 1110-2-3800 Office of the Chief of Engineers Washington, D. C. 20314 ENGINEERING AND DESIGN Systematic Drilling and Blasting Surface Excavations Table of Contents Subject Chapter i. Chapter 2. Cha~ter 3. INTRODUCTION Purpose Applicability References Duties of Government Construction Personnel Construction Inspector Resident Geologist Specifications Working Relationships Geological Information MECHANICS OF BMSTING Explanation Partitioning of Energy Peak Pressure and Shock Wave Elastic (Seismic) Waves Air Waves Fragmentation Near an Explosion Zones of Deformation Spalling Combined Role of Expanding Gases EXPLOSIVES AND THEIR PROPERTIES Explanation Properties of Explosives Strength Detonation Velocity Density and Specific Gravity Detonation Pressure Water Resistance Fume Class Ingredients of Explosive s for i March 72 Paragraph l-i i-2 1-3 i-4 l-4a l-4b 1-5 1-6 1-7 2-1 2-2 2-2a 2-2b 2-2C 2-3 2-3a 2-3b 2-3c 3-1 3-2 3-2a 3-2b 3-2c 3-2d 3-2e 3-2f 3-3 m f-’l 1-1 1-1 1-2 1-2 1-2 1-2 1-3 1-3 2-1 2-i 2-1 2-1 2-1 2-2 2-2 2-3 2-5 3-1 3-1 3-i 3-4 3-5 3-5 3-7 3-7 3-7 i EM iiiO-2-3800 i Mar 72 Subject Chapter 4. Chapter 5. Dyna&tes Straight Nitroglycerin Dynamite High- Density Ammonia (Extra) Dynamite . Low- Density Ammonia (Extra) Dynamite Gelatins Blasting Gelatin Straight Gelatin Ammonia Gelatin Semigelatin Blasting Agents (Nitrocarbonitrates) Dry Blasting Agents Slurries Other Explosive s TNT PETN Pentolite RDX Composition B Permissible Explosives Black Powder Detonators and Prime a s Blasting Caps Detonating Fuse Primers and Boosters Drilling Introduction Principles of Drilling Rotary Drills Roller Bits Diamond Bits Drag Bits Power Auger s Percussive Drills Rotary-Percussive Drills BMIC SURFACE BLASTING TECHNIQUES Introduction Blasting Patterns Hole Arrays Delay Patterns Paragraph 3-4 3-4a 3-4b 3-4C 3-5 3-5a 3-5b 3-SC 3- 5d 3-6 3-6a 3- 6b 3-7 3-7a 3-7b 3-7C 3- 7d 3- 7e 3-7f 3-7g 3-8 3-8a 3-8b 3-8c 4-1 4-2 4-3 4-3a 4-3b 4-3C 4-3d 4-4 4-5 5-i 5-2 5-2a 5-2b - 3-10 3-io 3-io 3-12 3-13 3-13 3-i3 3-i6 3-16 3-16 3-i7 3-i8 3-20 3-20 3-20 3-20 3-20 3-20 3-20 3-20 3-21 3-21 3-22 3-24 4-i 4-i 4-4 4-4 4-4 4-5 4-5 4-8 4-ii 5-i 5-i 5-1 5-3 ii EM ilf O-2-3800 1 Mar 72 Subject Arrangement of Charge in Hole General Rock Removal Bench Blasting Spacing and Burden Advantages of Inclined Blastholes Lifters and Snake Holes Varying the Hole Array to Fit Natural and Excavation Topography Charge Distribution Subdrilling Secondary Blasting Coyote Blasting, Trenching, and Cratering Underwater Blasting Underwater Surface Shooting Underwater Blasting in Drill Holes Excavation for Control of Rock Surfaces Presplitting Design of the Presplitting Layout Relationto Main Blast Presplitting Horizontal and Vertical Corners Horizontal Presplitting : Smooth Blasting Line Drilling and Close Drilling Precautions in Approaching Final Excavation Surfaces Blasting for Control of Rock Sizes Riprap - - - - - _- - - - - - - - - - - - - Aggregate Rock Fill for Dams Chapter 6. MODIFYINGBMTING TECHNIQUES TO FIT GEOLOGICAL CONDITIONS Exploratory Study Rock T~es Seismic Velocity Impedance - - - - - - - - - - - - - - - - - - - Compressive and Tensile Strengths Density and Porosity Fractures and Fabric Joint Frequency Cushioning Joint Coatings Paragraph 5-2c 5-3 5-3a 5-3a(i) 5-3a(2) 5-3a(3) 5-3a(4) 5-3a(5) 5-3a(6) 5-3a(7) 5-3b 5-3C 5-3C(I) 5-3C(2) 5-4 5-4a 5-4a(1) 5-4a(2) 5-4a(3) 5-4a(4) 5-4b 5-4C 5-4d 5-5 . 5-5a 5-5b 5-5C 6-i 6-2 6-2a 6-2b 6-2c 6-2d 6-3 6-3a 6- 3b 5-3 5-4 5-4 5-4 5-5 5-6 5-8 5-11 5-ii 5-12 5-12 5-i3 5-14 5-14 5-14 5-15 5-15 5-19 5-20 5-20 5-2i 5-21 5-23 5-23 5-24 5-24” 5-25 6-1 6A i 6-i 6-2 6-4 6-4 6-4 6-4 6-7 . . . 111 EM lii O-2-3800 i Mar 72 ‘ Subject Ori&ntation of Joints Orientation in Various Geological Settings Adverse Orientations Faults and Breccia Fabric Bedding and Stratification Alternating Rock Types Porous and Permeable Beds Weak Beds or Zones Dipping Strata Catities - - - . - - - . - - - Weathering Groundwater Chapter 7. DAMAGE PREDICTION AND CONTROL Introduction Airblast . - - . . - - - Damage from Airblast Propagation of Airblasts Excessive Airblast Pressure Recording Equipment Ground Vibrations Damage from Ground Vibration Recording Equipment Propagation of Ground Vibrations Reducing Vibrations Calibration of Site Vibration Levels Flyrock - - - - - - - - - - - - - - Chapter 8. DRILLING AND BLASTINGINROCK EXCAVATION BY CONTRACT General - - - - - - -, - - - - - - - - - - - - -,- - - - Customary Contract Approach Variation of Customary Approach Considerations in Preparation of Plans and Specifications Stated Principles of Plans and Specifications Pertinent General and Special Provisions - - - - . . - - - . - - - - - - - Geologic Data Review Plans for Practicalityof Excavation Outlines iv } Paragraph 6-3c 6-3c(I) 6-3c(2) 6-3d 6-3e 6-4 6-4a 6-4b 6-4c 6-4d 6-4e 6-5 6-6 7-i 7-2 7-2a 7-2b 7-2c 7-2d 7-3 7-3a 7- 3b 7-3C 7-3d 7-3e 7-4 8-i 8-la 8-lb 8-2 8-2a 8-2b 8-2c 8-2d 6-7 6-8 6-9 ;:;1 6-i2 6-i2 6-i3 6-13 6- i4 6- i4 6-i5 6-i6 7-i 7-1 7-2 7-2 7-4 7-4 7-5 7-5 7-ii 7-12 7-i5 7-16 7-i7 8-i 8-1 8-i 8-2 8-2 8-2 8-3 8-3 EM 1110-2-3800 1 Mar 72 Paragraph ., Subiect Construction Inspection To Be Expected Blast Records Sequence of Operations Specifying Methods–Obtaining Sound Walls Obtaining Final Grade Specifying and Prohibiting Certain Practices Requiring Gradation Ranges in Blasted Rock Vibration and Damage Control 8-2e 8-2f 8-2g 8-3 8-3 8-4 8-2h 8-2i 8-4 8-4 8-2j 8-4 8-2k 8-21 8-4 8-7 A-1 B-1 Appendix A - References Appendix B - Ty-pical CE Blasting Specifications Index - I-i List of Illustrations Title Fig. No. Zones of fracturing and deformation around an explosion in rock - - - - - - - - - - - - - - - - - - - - - - - Tensile fracture by reflection of a compressive strain ~lse Common sizes of dynamite cartridges Nomograph for comparing weight strength and cartridge strength Some relative properties and ingredients of commercial explosives Nomograph for finding detonation pressure Average confined velocity and specific gravity and calculated detonation pressure of explosives - - - - - - - - - - - - - - - - - - - - - - - - - Application of blasting caps Safety fuse and cap Millisecond delay connectors Types of failure induced bya drill bit 2-1 2-2 2-2 3-1 2-4 ?-2 3-2 3-3 3-3 3-4 3-4 3-6 3-5 3-6 3-7 3-8 4-1 3-8 3-2i 3-23 3-24 4-2 v EM 1110-2-3800 i Mar 72 Title Relationbetween quartz content and uniaxial strength of sedimentary rock Relation of compressive strength and bulk speciiic gravity for basalt Track-mounted rotary drill (9-in. bit) Roller bits used in quarrying rock of different hardness Small-diameter diamond bits (3 in. or smaller) Drag bits Typical surface jackhammer drill design Bits and steel assembly. for surface hammer drills Bits for down-the-hole hammer drill Wagon drill Crawler drill capable of drilling holes from 1- 3/4 to 3 in. in diameter Churn drill bit Rotary-percussive drill bit Basic blasthole array s Variation of regular arrangement of production blastholes as necessitated by topography Single-hole arrays - Some possible delay patterns Trapezoidal blasting pattern Shock-wave propagation through rock generated by detonation of toe charge Bench- slab movement during blast with vertical and inclined holes - Typical placement of snake hole Varying the direction of throw by arrangement of delay s Multiple- row round including a V- cut opening Large quarry blast pattern measuring 600 by 400 by48 ft Delays, in milliseconds Distribution of inclined holes for a road cut in uneven topography. Regular hole array dis- torted to fit topography Charge distribution in bench blasting Plan of coyote layout with detonating cord Blasthole patterns for underwater blasting Presplit blasting in limestone for a powerhouse Presplit fracture Section of typical presplit holes ready for firing , Fig. No. 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-io 4-11 4-12 4-13 ,4-14 5-1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9 5-1o 5-ii 5-12 5-13 5-14 5-15 5-16 5-17 5-18 5-19 m 4-2 4-3 4-5 4-6 4-7 4-7 4-9 4-io 4-1o 4-11 4-i2 4-13 4-14 5-1 5-2 5-2 5-3 5-5 5-6 5-7’ 5-7 5-8 5-9 5-9 5-10 5-40 5-12 5-13 5-14 5-i6 5-17 5-18 vi EM iii O-2-3800 1 Mar 72 Title Relation of presplit to main pattern Use of guide holes in presplitting inside and out- side corners Typical arrangement of line drilling with respect tomain blastholes Main charge delay s Plan of blasthole pattern for fragmentation of rock to produce aggregate - Typical impedance calculation for granite - Empirical relation: blasthole spacing and diameter and powder factor for multiple- row blast pattern in rocks of different strengths Sonic log travel time as a function of porosity for a suite of volcanic sedimentary rocks and lava Adverse dip of joints into excavation Variation of shear strength with inclination to schist osity (y-z plane) in fine -grained gneiss Effect of dipping strata on stability of excavation Propagation laws for airblast pressure from spherical charges for various scaled depths of burial and from quarry blasting rounds Summary of damage criterion data for frame structure Summary of nondamaging data above recommended safe vibration level for frame structures Subjective response of the human body to vibratory motion Particle-velocity data versus distance for one site Maximum observed ranges of natural missiles for buried explosions in basalt Example OL one form of blasting log kept by contractor Record of blasting required by one CE District Fi~.No. 5-20 5-21 5-22 5-23 5-24 6-1 6-2 6-3 6-4 6-5 6-6 7-i 7-2 7-3 7-4 7-5 7-6 8-1 8-2 m 5-20 5-21 5-22 5-24 5-25 6-2 6-5 6-6 6-10 6-11 6-14 7-3 7-6 7-i’ 7-9 7-14 7-i8 8-5 8-6 tii EM ii10-2-3800 i Mar 72 , viii EM 1110-2-3800 i Mar 72 “ CHAPTER 1. INTRODUCTION l-i. Purpose. This manual describes reliable or preferred procedures or concepts of drilling and blasting conducted during rock excavation, in order to aid design and construction personnel in related matters (para 1-4). Drilling and blasting methods described herein are not to be regarded as official Corps of Engineers (CE) policy, but they should be of assistance to CE personnel in establishing policy. The manual is designed principally for the use of geologists and engineers who are given resp~nsibilities in drilling and blasting projects. Such re- sponsibilities may come either in the design or in the construction phase. i-2. Applicability. The provisions of this manual are applicable to CE Divisions and Districts concerned with Civil Works design and construction. 1-3. References. a. Department of the Army publications on related subjects are listed below-: (1) ER 1110 2-1200 (2) EM 385-I-I (3) EM ii10-i-i80i (4) EM il10-i-i806 (5) EP 415-I-261 (6) TM 5-332 Plans and Specifications General Safety Requirements Geological kvestigations Presenting Subsurface Information in Contract Plans and Specifications Construction Inspectors Guide Pits and Quarries . b. Strict adherence to safety precautions in blasting is of ut- most importance. Publications specifically on safety in blasting include: The 420 Handbook of Electric Blasting Atlas Chemical Industries, Inc., Explosives Division Manufacture, Storage, Trans- lational Fire Protection portation and Use of Explo- Assoc. sives and Blasting Agents, 1968 Rev Ed. following are obtainable from Institute of Makers of Explosives, Lexington Ave., New York, N. Y. iooi7 i-i e . Manual 11 10-2-3800 Department of the Army U.S. Army Corps of Engineers Washington, DC 20 314 -10 00 EM 11 10-2-3800 1 March 19 72 Engineering and Design SYSTEMATIC DRILLING AND BLASTING FOR SURFACE EXCAVATIONS Distribution. for i March 72 Paragraph l-i i-2 1- 3 i-4 l-4a l-4b 1- 5 1- 6 1- 7 2 -1 2-2 2-2a 2-2b 2-2C 2-3 2-3a 2-3b 2-3c 3 -1 3-2 3-2a 3-2b 3-2c 3-2d 3-2e 3-2f 3-3 m f-’l 1- 1 1- 1 1- 2 1- 2 1- 2 1- 2 1- 3 1- 3 2 -1 2-i 2 -1 2 -1 2 -1 2-2 2-2 2-3 2-5 3 -1 3 -1 3-i 3-4 3-5 3-5 3-7 3-7 3-7 i EM. No. 4-2 4-3 4-4 4-5 4-6 4-7 4-8 4-9 4-io 4 -11 4 -12 4 -13 ,4 -14 5 -1 5-2 5-3 5-4 5-5 5-6 5-7 5-8 5-9 5-1o 5-ii 5 -12 5 -13 5 -14 5 -15 5 -16 5 -17 5 -18 5 -19 m 4-2 4-3 4-5 4-6 4-7 4-7 4-9 4-io 4-1o 4 -11 4-i2 4 -13 4 -14 5 -1 5-2 5-2 5-3 5-5 5-6 5-7’ 5-7 5-8 5-9 5-9 5 -10 5-40 5 -12 5 -13 5 -14 5-i6 5 -17 5 -18 vi EM