Validation of Slopes of Access Roads in Deep Open Pit Mining

Resumo

It is found that the slope of access roads influences adds to flattening of nonmining pit walls where the access roads are driven. Aiming to determine the over-flattening of nonmining pit walls, the quick and accurate analytical method is developed. It is proved that the increase of the slope of access roads to the maximum possible values (20–24%) enables reduction in stripping by 20–40% in deep open pit mines. The mining efficiency in case of steep slopes, aside from extra flattening of nonmining pit walls, is also influenced by the depth of transition to such slopes and the transportation capacity of the access roads depending on distribution of mining operations along the depth of an open pit mine. It is demonstrated that it is most reasonable to gradually increase the slope of access roads with the mining depth, starting from the initial value (8%) and up to the maximum governed by technical requirements and operating conditions.