METHOD TO PROVIDE FOR STABILITY OF HIGH LEDGES Russian patent published in 2010 - IPC E21C41/26 

FIELD: mining.

SUBSTANCE: invention is referred to a mining industry and can be used at development of mineral deposits. The method involves offset of steeply inclined and vertical ledges and board areas within middle and deep zones and application of traditional schemes for deviation of ledges and their fortification at the destruction stage with tension bars and resins. First one separates the stripping stratum of rock vertically into zones depending on fissuring and strength properties and offsets in them inclined, steeply inclined, vertical board areas with fixation in upper, middle and sometimes - deep zones during an open pit modification and deepening. Offset of a ledge slope on a berm horizon is performed with account for the row of production wells arranged above in proximity to the planned slope and berm. For that one places in them, to a height close to half the height of subgrade drilling, a strengthening mixture represented by a cement mixture or resin that during performance of explosive works flows into cracks and cements them. The water to cement ratio or the share of hardening additives to the resin is regulated with account for abundance of water in the rock and the duration of the period from the mixtures laying to performance of explosion and is introduced immediately before it. After formation of a cutoff crack and explosion of main wells and removal of rock to the ledge roof level one additionally strengthens the slope mass close to the ledge by way of drilling blast-holes along the slope and sets anchors in them which are connected to the bars inside outside the destruction-shear wedge. To retain the blocks and prevent their displacement in the slope one connects the anchors and the bars with a cable in a serpentine way; from the side of the slope wells (blast-hole) are drilled for anchors into the strengthened areas according to a certain grid corresponding to the strengthened elements and a metal net is hung at the height of the wedge destruction and on the surface to the retaining bars; in conclusion one performs filling with a cement mixture to prevent water inflow.

EFFECT: improved stability of the ledges.

1 ex, 6 dwg