Systematic Drilling and Blasting for Surface Excavations Part 11 docx

... from and calculated particle velocities damage criterio~ for unlined tunnels explosion is about 20 ips for the Table 7-1. Strain and Particle Velocity at Failure for Five Rocks Dynamic Particle Breaking Propagation Velocity Strain Velocity at ... plotted points in Fig. 7-1 7-2 EM 111 0-2-3800 1 Mar 72 !. I .0 t 111 11 I I o. I 0.01 0.001 0.0001 0 8 A I I I Ill Oomoge criterion v....

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... Engineers Washington, DC 20314-1000 EM 111 0-2-3800 1 March 1972 Engineering and Design SYSTEMATIC DRILLING AND BLASTING FOR SURFACE EXCAVATIONS Distribution Restriction Statement Approved for public release; distribution ... Presplitting Horizontal and Vertical Corners Horizontal Presplitting : Smooth Blasting Line Drilling and Close Drilling Precautions in...

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... antici- pated for the future. The drilling and blasting manual for surface exca- vations is the first of this series. Selected references that describe drilling and blasting procedures and results ... cavity. 2-3 EM 111 0-2-3800 1 Mar 72 Standard Storage Magazines, i957, Pamphlet # Safety in the Handling and Use of Explosives, 1960, Pamphlet i7 How to Destroy Explosives...

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... Mar 72 CWPTER,5. BASIC SURFACE BMTING TECHNIQUES 5-1. Introduction. a. Rock blasting may be conducted for removal of rock, for con- trol of excavated rock surfaces, and for control of blasted ... techniques used for surface excavations. Information was obtained from CE District offices and projects supplemented in less familiar procedures by references 8 and 14. 5-2. Bla...

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... 80 CARTRIDGE STRENGTH, percent Fig. 3-5. Average confined velocity and specific gr~vity and calculated detonation pressure of explosives 3-8 E,M 111 0-2-3800 i Mar 72 Table 3-2. Properties(i) of Dynamites Weight Cartridge Confined Strength ... Dynamite i.3 12,500 Fair 1.3 ii,500 Fair 1.3 10,500 Fair 1.3 9,000 Fair 1.3 8,000 Fair Poor Poor Poor Poor Poor Good Good Good Good Good i06 i 04...

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... largely replaced dynamites and gelatins in bench blasting. Denser slurry blasting agents are supplanting dynamite and gelatin and dry blasting agents. 3-16 E,M ili O-2-3800 i Mar 72 . excavation blasting in ... will disperse relatively rapidly and uniformly. (4) Inadequate priming imparts a low initial detonation velocity to a blasting agent, and the reaction may die out a...

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... The marked insensitivity to external shock and friction makes a detonating fuse ideal for both down lines and trunk lines for primary blasting. Since the blasting cap need not be connected into ... 72 SOFT ROCK BIT -FOR CLAY, SHALE, SALT, GYPSUM, CHALK, AN HYORITE, AND MEDIUM LIME ROCK. MEDIUM ROCK BIT - FOR LIME- STONE, DOLOMITE, HARD SHALE, AND AN HYDRITE. HARD ROCK BIT -...

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... retain gases and reduce noise and flyrock. Table 5-1. Charge Concentration of Inclined Holes (i) for Single-Row Bench Blasting for Fragmentation with Respect to Various Burdens and Hole Diameters ... airblast, and breakage with a drop ball is pre- ferred wherever that equipment is adequate and available. b. Coyote Blasting, Trenching, and Crate ring. (1) Coyote blasting (...

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... the bottom and for close hole spac- ing should be much less. (2) Relation to Main Blast. Presplitting and primary blasting are sometimes performed in one operation with the presplit and pri- mary ... iiiO-2-3800 i Mar 72 Table 5-3. Some Typical Hole Spacings and Diameters, Charge Concentrations, and Burdens for Smooth Blasting (after Langefors and Kihlstr6m14) Drill Hole C...

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... heav- ing effect for loosening and moving material. (2) Presplit blasting for a finished rock surface may be more difficult in highly fractured rock depending partly on the nature and atti- tude ... compressive and tensile strengths for a selected group of rocks with divergent properties. (2) Fig. 6-2 is an empirical chart useful for estimating blasthole spacing and size...

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