Blast Contours

Blast Contours. This subject was discussed by Cook (1958), pp 106-14 and many photographs of contours are given. In Fig 5.11, 

Binding Energy. See Vol 1, p A500-R under Atomic (or Nuclear) Energy 

Birth (Initiation) and Growth of Explosion in Solid and Liquid Explosives Initiated by Impact, Friction, etc. See Vol 2, p B127-L and under Detonation (and Explosion), Initiation (Birth), Growth, Spread and Propagation in Explosive Substances 

Blast Effect in Air, Earth and Water. See Vol 2, pp B180-B184, Cook (1958), pp 106-13 353-75, and Dunkle s Syllabus (1957-58), 

Blast Effects Due to Reflected Shock Waves. See Vol 2, p B182-L 

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Figure 6.2 Plot plan and calculated blast contours for Example 12.

Similarly, by comparing the blast contours from Figure 6.2 with Table 3.5, it is clear that Buildings 3, 4, and 5 also require further evaluation. In particular, Building 3 will be subject to approximately 1 psi blast from both Process Units 1 and 2. Building 4, the trailer complex, is of particular... 

Figure 6.11 Cross-sectionai diagram of a blast contour in air...

Study of the blast contours of HE s provides V (S) data for the lateral initial shock wave during its lifetime, i.e. in the interval between its creation and obliteration by the oncoming pressure wave. It is known that the actual particle-velocity vector of the initial lateral shock wave is not quite perpendicular to the charge axis, but somewhat in the forward position (Ref 53, p 323)... 

In the same Chapter 5 of Cook are discussed Blast Contours (pp 106-11),... 

Explosion consequences in terms of overpressure and other effects may be evaluated by appropriate methods such as those described in Reference 5 and Appendix A. In evaluating the consequences of potential explosions, all these methods account for the energy of the explosion, the location of the explosion source, and attenuation of explosion effects with distance from the explosion source. From such an evaluation, maximum blast parameters can be determined at all locations of interest. Evaluation results can be graphically expressed by plotting contours of equal blast overpressure on a site plan of the facility, as shown in Figure 4.4. 

Table 5.3 may be used in conjunction with the estimate of blast overpressure contours discussed previously to conduct a qualitative site assessment for the design and siting of buildings in process plants. 

Presplitting. A technique of blasting which gives accurate finished contours (see p. 148). 

High explosives like RDX, HMX or PETN with a polymeric binder form a flexible explosive material that can be rolled into sheet form which can be cut and applied to any contour. They have a variety of applications from metal cutting to demolition and blasting to armor protection. Some important characteristics of sheet explosives are-flexibility, moldability, waterproofness and safety in handling. Also, sheet explosives can easily be cut and initiated. 

Note The purpose of smooth or controlled blasting is to produce an excavation contour, while leaving behind an intact, fissure-free formation. This is done by the use of diminished-strength expl charges, using numerous boreholes, driven exactly in parallel Ref R. Meyer, Explosives , Verlag Chemie, NY (1977), 239 314... 

A method of blasting in which an air space is left between the explosive charge and the stemming, or in which the blast hole is purposely drilled lager than the diameter of the explosive cartridge to be loaded - Contour Blasting. 

A -> Contour Blasting method in which cracks for the final contour are created by firing a single row of holes prior to the blasting of the rest of the holes for the blast pattern. 

Trade names of - Detonating Cords containing 40 and 100 g PETN/m distributed in Germany and exported by DYNAMIT NOBEL. It is covered with red-colored plastic. It is used for the initiations of ANFO blasting agents and for Contour Blasting. 

Figure 11.10 Schematic of the blowing stage, (a) The molten, hollow tube — the parison or preform — is placed between the halves of the mold (b) the mold closes around the parison (c) the parison, still molten, is pinched off and inflated by an air blast that forces its wall against the inside contours of the cooled mold (d) when the piece has cooled enough to have become solid, the mold is opened and the finished piece is ejected. (From Kaufman, H.S. and Falcetta, J.J., Eds., Introdur ion to Polymer Science and Technologies, John Wiley Sons, New York, 1977. With permission.)...

Holmberg, R., Persson, P. A. (1978, February 1-3). The SwedishApproach to Contour Blasting. Conference on Explosives and Blasting Technique. Society of Explosives Engineers, New Orleans, Louisiana, USA. 

Pearl, R.M., Laub, D.R., and Kaplan, E.N. (1978) Complications following silicone injections for augmentation of the contours of the face. Blast Reconstr Surg, 61(6) 888-891. 

The diagram in Fig. 10.31 compares spherical detonations (left side of the diagram) with a cylindrical detonation with a disk-shaped fuel volume (right side of the diagram). The detonation front is displayed with a heavy black solid line, the cloud contour - with the dashed line. The resultant blast wave displacement outside the cloud in sequential instants of time to < < 2 is marked by the chain lines. 

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