Systematic Drilling and Blasting for Surface Excavations Part 10 potx

... Introduction. a. A necessary part of all blasting operations is the estimation of potential damage to nearby surface and underground structures and to local rock surfaces that are to remain in ... be made. c. Methods and techniques for preventing damage by cent rolling the amount of airblast, ground vibration, flyrock, and cracking are gen- erally known and should be made a...

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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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... 20314 -100 0 EM 1 110- 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. EM ... Presplitting Horizontal and Vertical Corners Horizontal Presplitting : Smooth Blasting Line Drilling and Close Drilling Precautions in Appro...

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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 ... second (fps) and in strong rock with little jointing, it will travel as fast as 20,000 fps. P- and S-waves perform work by moving the rock particles Longitudinally and...

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... 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 ioo 100 ioo 110 iio 110 110 110 Low-Density Ammonia Dynamite, ... h1" alt="" WEIGHT STRENGTH, CARTRIDGE STRENGTH, PERCENT PERCENT 100 90 80 70 60 50 40 30 20 10 100 90 80 70 60 30 20 10 EM 1 110- 2-3800 1 Mar 72 CARTRIDGE COUNT,...

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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 ... good 63 30 0.9 10, 500 Fair Very good 110 105 ioi 98 95 92 88 85 106 102 ioo 97 92 90 110 118 130 150 Note: Values shown are the averages of several manufacturers....

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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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... steel assembly for surface ham- mer drills (figures show drive- on and threaded connections)9 ) TYPICAL STEEL AND SIT ASSEMBLY Fig. 4-i O. Bits for down- the- hole hammer dril19 4 -10 EM il10-2-3800 i ... 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...

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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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