Recovery box
A recovery box is a rectangular box, which is assembled from pit wood and filled with mountains , and which is used to support the hanging wall. Recovery boxes support a larger area, a lot of wood is needed to create them. Recovery boxes also create a high level of weather resistance . In addition, their construction is very labor-intensive.
construction
The recovery box, like the wooden box, consists of a square of squared timber or railway sleepers . The spaces between this square are filled with mountains. Due to the recovery filling, the box has a higher load capacity. A certain resilience is achieved by the fact that the mountain filling is not packed too tightly. So that the recovery box reaches directly to the hanging wall, the space between the box and the ridge is filled with a suitably thick slab of wood .
particularities
The resilience of the recovery boxes must be at least as great as the resilience of the filling of the neighboring seam area . If the resilience of the recovery boxes is lower, i.e. if the load-bearing capacity of the recovery boxes is greater, then tensions are concentrated above and below the recovery boxes. These tensions are triggered by the rock pressure and often lead to crack formation in the hillside rock. In addition, these tensions lead to lateral movements of the track impacts . In addition, these tensions cause the sole to swell. If recovery boxes are filled with chunks of sandstone , then they are up to five times more load-bearing than simple, similarly designed but unfilled wooden boxes .
use
Just like wooden boxes, recovery boxes are used wherever cavities in the mines have to be supported, but the space for a stamp is too high. Recovery boxes are used in particular to secure the line edge from the consequences of dismantling . Recovery boxes are also used to secure seams in mining stretches with flat storage. When building pillars , recovery boxes are placed between the rows of punches to reduce the pressure on the punches. The boxes will, if possible, be recovered as degradation proceeds. In order to avoid excessive pressure at the crossing points of conveyor lines, recovery boxes are used in the area of the line crosses.
Individual evidence
- ^ A b Walter Bischoff , Heinz Bramann, Westfälische Berggewerkschaftskasse Bochum: The small mining dictionary. 7th edition, Verlag Glückauf GmbH, Essen 1988, ISBN 3-7739-0501-7
- ^ A b c d e Carl Hellmut Fritzsche: Textbook of mining science. Second volume, 10th edition, Springer Verlag, Berlin / Göttingen / Heidelberg 1962
- ↑ a b Horst Roschlau, Wolfram Heinze, SDAG Wismut (Hrsg.): Knowledge storage mining technology. 1st edition. German publishing house for basic industry, Leipzig 1974, p. 85.
- ↑ a b c d Albert Serlo: Guide to mining science. First volume, fourth revised and up to the most recent edition supplemented, published by Julius Springer, Berlin 1884
- ↑ J. Weißner: Findings from the observation of mountain movements for mining. In: Glückauf, Berg- und Hüttenmännische magazine. Association for mining interests in the Oberbergamtsiertel Dortmund (Ed.), No. 41, 72nd year, October 10, 1936, pp. 1030-1032.