Passing bays in an underground mine

Abstract

Some mining companies are investigating the use of road trains to increase productivity in underground mines. Road trains require dedicated passing bays in declines. The spacing of these passing bays can have a significant impact on haulage productivity. This technical note describes the use of simulation to find the optimal spacing. If the distance between passing bays is sufficiently small then descending trains can be interleaved with ascending trains, which increases productivity. If the spacing is too small, however, productivity can decrease as descending trains wait in passing bays for ascending trains. For a real mine the spacing should be less than the theoretical critical distance to cope with variations in loading and unloading durations.

Efficient vehicle haulage in underground mines

“…We observed in our previous paper (Anjomshoa et al, 2010) that the best locations of a fixed number of passing bays are those that are precisely spaced to allow interleaving of vehicles without delays at bays, and we simulated the vehicle movements in a proposed underground mine to confirm this observation. Simulation has been widely used to study and improve operations in the mining industry.…”

“…We developed an algorithm that ensures that descending vehicles can be refuged in bays before encountering any ascending vehicles. Anjomshoa (2011) demonstrated that this deadlock avoidance method is less restrictive than the one implemented by Sturgul et al (1996), in which deadlock is avoided by allowing only ascending vehicles to follow on a segment.…”

“…The simulator described by Anjomshoa et al (2010) models the movement of vehicles through a mine for specified passing bay locations. A key requirement is that vehicles do not deadlock and thus force a vehicle to reverse.…”

“…The MIP formulation encapsulates the entire model requirements described earlier. The precise mathematical notation and formulations of these constraints is given by Anjomshoa (2011).…”

“…In this paper, we summarise our two approaches: (i) the simulator we developed (Anjomshoa et al, 2010) to model the movements of vehicles through a mine for specified passing locations; and (ii) a mixed integer programming (MIP) model that we developed to find the optimal locations of passing bays and optimal vehicle schedules. [Full details of the mathematics are given by Anjomshoa (2011) and Anjomshoa et al (2011).] However, our main focus in this paper is to interpret the results from our two approaches as they apply to mine design and operations with haulage trucks or road trains.…”