Theoretical principles of redundancy and patterns of transport and technological complexes' adaptation to the operating conditions

The paper addresses the issues of improving the performance of the handling and transport complex at a mining enterprise. It presents statistical estimates for the general standard reliability of the transport system, which should correspond to similar indicators of subsystems of equipment, machinery, etc. We studied the operation of a rock mass transportation system used in open-pit mines. The handling and transport complex includes dump trucks of various capacities and a single-bucket elevator. The process of rock mass excavation and transportation depends on weather and climatic conditions. Among the factors that affect the transport system performance, the following can be distinguished: air temperature, snowdrifts, gas accumulation in the pits, and, as a result, reduction of the visibility range, leading to a decrease in the average speed of vehicles. The mathematical models of transportation are based on the well-known methods of forming excavator and truck fleets. To calculate the reliability of the transport system in the pit, it is necessary to have data on the probability of no-failure operation and the mean time between failures for each vehicle. Information about the state of the vehicles was obtained based on the results of statistical analysis. During optimization calculations, the following restrictions and assumptions were accepted: the limit state of a vehicle was determined by the mileage of 250,000 km; the distribution of the fleet vehicles' mileage was subject to the Weibull law with the variation factor approximately equal to 1. In this case, the distribution of the mean time between failures can be considered exponential. Analysis of statistical data on the operational reliability of vehicles showed that random failures prevail. When simulating the operation of handling and transport complexes, it is necessary to take into account the parametric and technological connection between individual machines operating within these systems. The developed methodology for justification of the level of equipment adaptation to the operating conditions is aimed at improving the reliability of handling and transport complexes involved in mining production. © 2021 Elsevier B.V. All rights reserved.