For the implementation of the tests for explosive-based cable bolts, three different explosives – gunpowder, emulsion dynamite and gelatinite dynamite – were used (Thompson, 285-291). The amount of explosive to be placed into the cap is very important. If the amount of explosive becomes relatively high, a greater than required pressure will be applied onto the borehole wall. As a result of this pressure, some cracks may occur in the rockmass. In contrast to this, if the explosive is less than needed, the cap will not expand adequately, and the anchorage capacity will be decreased.
According to calculations carried out for the gelatinite dynamite, the required amount of the explosive was found to be ~7•80 g. However, this amount is only a reference quantity for a first approach. The real quantity, found using the trial and error method in the tests, amounts to 7•5 g/cap. Similarly, explosions are conducted on large scales in the destruction of buildings, in a way that the surrounding areas have minimal effects of the dynamite blasts and the tasks of the engineers are accomplished very efficiently and effectively (Perrings, 129-135).
“In 1867 dynamite was invented, and in 1869 the mechanical drill run by compressed air was invented. These two inventions created a technological revolution in the mining industry. Dynamite was safer and easier to control than black powder. A steam engine-driven air compressor for the mechanical drill was generally installed outside the mine, and air lines were extended to the drills under ground. Most mines were worked on a small scale, with only a few miners and support personnel.
” (Technology of Colonial and Victorian Iron Mining) The anchorage of the first 8 concepts was provided by a friction force developed through expansion of the cap in the borehole wall. However, for the oblique concept, a rotational moment has been additionally created by the pulling of the cable attached to the cap. The cap designed for this concept. In this concept, the upper part of the cap has been designed to be inclined.
There were also 2-mm deep scratches on the cap as for the other concepts. These scratches facilitate the expansion of the cap. In this system, the barrel and wedge anchor for holding the cable causes the rotational moment on the cap. This rotational moment gives rise to additional friction between the cap and the borehole wall. These oblique caps are illustrated. The invention of dynamite in the middle of 19th century was surely a breakthrough in some of the industrial processes.
It was through this dynamite that, Alfred Nobel made further discoveries and went on to make a number of industries. The use of dynamite still dominates in the mining and construction industries and is considered to be one of the most significant discoveries of its time.
New Discoveries of Alfred Nobel. (2019, Dec 05). Retrieved from https://paperap.com/paper-on-1996-dynamite-alfred-nobel/