Crushed stone wall

CRUSHED STONE WALL (EN: rubble band; DE: Bergerippe, Bergedamm; FR: mur de remblais; ES: banda de relleno; RU: бутовая полоса) is the stowing massif, which is erected in the form of the strip within the mine working. They use the stone walls during the development of the thin layers, veins, and lenses of the useful minerals, within the longwall stopes, for the control of the roof support by the partial stowing (especially in the case of the unstable rocks), and also for the protection of the extended mine workings during the conducting of them with the usage of the wide stope. They situate the crushed stone walls along the strike of the layer, or along the dip of the layer; the width is 6-12 metres, sometimes 4-6 metres (the walls near the drifts). Within the steep layers, the crushed stone walls are supported at the side of the dip by the chock roof support. The quantity and the width of the crushed stone walls must ensure the support of the major roof against the collapsing. For the laying of the crushed stone walls within the longwall stopes, they use the rock from the specially conducted crushed stone drifts. They erect the crushed stone walls, which are replacing the protective virgin rock pillars of the useful minerals, of the rock, which is obtained along the way (from the ripping of the roof) during the conducting of the mine workings; for the protection of the repeatedly used single excavating mine workings, they use the natural anhydrite or the gypsum-cement. In order to decrease the rock pressure onto these mine workings, they sometimes lay the double crushed stone walls with various density (flexible and stiff). The carrying ability of the crushed stone wall depends on the strength and size of the pieces of the rock, and also on the density and thoroughness of the laying.