Rational design of ore discharge bottom in transition from open pit to underground mining in udachny mine

Simultaneous extraction of ore reserves from open pitwall and the layer immediately adjacent to the open pit bottom results in higher volume of ore discharge in the limited bottom area, besides the bottom must be stable within the adjacent layer extraction interval. The authors select the pit bottom design with two-way alternate arrangement of loading entries, taking into account the use of power-driven load-haul-dumpers. The ore output with the given pit bottom design is evaluated.