Surface blasting

The fuel-air explosion produced, in a large area covered by the cloud, substantially higher blast pressures than would be expected from a 100,000-kg TNT surface blast. 

K. Malkovsky R. Mecir, Rudy 12(9), 345-49(1964) CA 62, 8924(1965) (Description of Czech expl Permon Extra, which is suitable for large-diameter boreholes in surface blasting)... 

Pennon Extra. A CzecHiexpl used for large diam boreholes in surface blasting. 

Work by the USBuMines in ground motion transmission (Ref 2) produced two particularly significant results for the typical charge weights and distances found in surface blasting 1) the constant m is equal to one-half of the constant n the power law equation then has only two unknowns and assumes the following form ... 

Cratering of Greenland icecap snow has been studied using 20-ton (Ref 56) and smaller (Ref 94) surface blasts. Tests have been run on structures constructed of snow (Ref 39). Shock pressures have been measured from the expln of TNT spheres at various depths below 2 ft of ice (Refs 40 47)... 

Dubova, Waves in Soil During a Surface Blast and their Interaction with Obstacles , FTD-HT-23-744-72 (Transi), Foreign Technol Div, Wright-Patterson AFB, Dayton (1972) 115) L,... 

Caggiano, Calculation of TNT Air-Blast Equivalences for Surface Blasts , PATR 4567 (1973) 19) R.S. Kukuvka K. Gandhi, Propagation Tests of 55Pound Boxes of Bulk TNT and 60-Pound Boxes of Bulk Composition B , PATR 4622 (1973) (Limited distrib) 20) J. Edel-maier, Makeshift Processing of Trinitrotoluene ,... 

We do know that the variables or parameters that seem to be important in relation to surface blasts are as follows ... 

Notice that neither Chabai nor Baker includes the explosive CJ pressure among the important variables. That is reasonable since the work here is in lifting, PV work. Shattering and shock coupling with resulting surface spalling, which played an important role in the formation of surface blast cratering, are not major effects here. 

C. Subsurface Burst. A subsurface burst weapon is detonated beneath the surface of land or water. Cratering will generally result from an underground burst, just as for a surface burst. If the burst does not penetrate the surface, the only other hazard will be from ground or water shock. If the burst is shallow enough to penetrate the surface, blast, thermal, and initial nuclear radiation effects will be present, but will be less than for a surface burst of comparable yield. Local fallout will be very heavy if penetration occurs. 

Konya, C. J., and Walter, E. J. (1990). Surface Blast Design. Prentice-Hall Englewood Ciffs, NJ, p. 303. 

Cost-benefit analysis associated with four organic coatings used in the mining industry with surface preparation such as surface blasting or no surface preparation led to the finding of the data included in Table 4.44. 

Development of a New Blast Vibration Prediction Model Incorporating Burden Variations in Surface Blasting... 

Ambraseys and Hendron (1968) found that the value of a is 1/2 for all surface blast vibration attenuations. The value of p ean be adjusted as 1.6 as it satisfies the attenuation eharacteristics of most ofthe rock types (MeKenzie, 1993 Konya,... 

Mortazavi, A., Katsabanis, P. D. (2001). Modelling burden size and strata dip effects on the surface blasting process. International Journal of Rock Mechanics and Mining Sciences, 38, 481-498. doi 10.1016/S1365-1609(01 )00015-6doi 10.1016/S1365-1609(01)00015-6... 

Singh, P. K. (2000). Evaluation of damages to underground coal mines caused by surface blasting vis-a-vis establishment of blast vibration threshold (Project No GAP/III/ BLASTING/MOC/1996, pp. 1-50). CMRI Coal S T. 

There is a whole range of possible variations in large-hole blasting practice, from single-row and multiple-row blasting with or without toe holes to so-called surface blasting. 

For successful use of wheel loaders the rock pile should be well fragmented, as the ripping and break-out forces that such machines can develop are only about one-sixth to one-third of those of comparable excavators. The wheel loader is thus unsuitable for the loosening of rock, a circumstance which limits its use as a loading machine in conjunction with quarrying by surface blasting, for example. 

Gloss level Grain Too glossy Surface blasting... 

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