METHOD OF SINKING OF VERTICAL MAIN SHAFTS OF UNSTABLE AND WATERFLOODED ROCKS Russian patent published in 2014 - IPC E21D1/12 

FIELD: mining.

SUBSTANCE: method comprises drilling of freezing wells around the shaft, in which the freezing columns are placed for formation of ice-rock fencing, sinking the shaft with cyclical stopes followed by installing lining and closing the behind-lining space. Acoustic monitoring of bearing capacity of ice-rock fencing is carried out. After drilling of freezing wells to a predetermined depth the aqueous solution of synthetic polypropylene fibre is injected into the annulus of each of them at a predetermined ratio of liquid and solid phases. The fibres dissolved in water rise to the mouths of the wells. Then drilling tools are removed from the freezing wells and the freezing columns are descended to them. Then the clay mud flush with synthetic polypropylene fibre is maintained for at least five days prior to formation of strong and waterproof layer between the outer walls of the freezing columns and the rock, then ice-rock fencing is created around the mine shaft.

EFFECT: providing trouble-free operation of ice-rock fencing, reduction in time of construction of the shaft and reduction of the material costs.

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