Hydrogeological justification of the effective operation of the underground drainage complex of quarry the Mikhailovsky mpp named after A. V. Varichev

The drainage of the quarry of the Mikhailovskoye iron ore deposit is carried out by a combined surface and underground method. With the planned development of the quarry in the north-west direction, the size of its drainage contour increases accordingly, which contributes to the growth of water inflows. It has been established that in recent years the average annual water inflow to the mine drainage varies within 2150...2830 m3/h. It was revealed that the absolutely largest part of the water inflows into the quarry falls on the Bathonian aquifer – 1 500 m3/h (77 %). In this regard, a forecast of water inflows from the Bathonian aquifer is made taking into account the expansion and deepening of the quarry bowl. To assess and predict the flooding of the quarry from the Bathonian sands, a numerical model of geofiltration of the Mikhailovskoye iron ore deposit area has been developed. The predictive modeling was carried out taking into account the construction of an additional drainage drift to the boundaries of the mining allotment for the placement of rising drainage boreholes on the Bathonian sands, since the existing drainage structures (drifts with rising boreholes) will be undermined by the quarry and partially decommissioned. It was found that the specific inflow on the north-western side of the quarry as a result of the construction of a drainage drift at the boundaries of the mining allotment will decrease by 1.5 times (from 1.2 to 0.8 m3/ day per 1 running meter of slope). Based on the results of predictive calculations of the total inflow of ground and surface water into the quarry, the required amount was substantiated and a layout diagram for the drainage units of rising drainage boreholes was developed to ensure effective drainage of the Mikhailovskoye iron ore deposit quarry up to 2032.