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We know from the practice of underground mining of solid mineral resources that transportation is one of the principal mining costs (the cost of carrying minerals, barren rock, equipment, etc. in the tunnels of the mine).Transportation costs can be minimized by optimizing the stripping plan and organizing an efficient transportation of loads.The importance of reducing underground traffic is increased as the mining operations advance to greater depths and is conducted in more difficult conditions. An analysis of this problem in [i], however, has shown that a general solution is difficult.The main source of the difficulties is the lack of a formalized description (models and objective functions) describing the load traffic in underground mines.In 1975 the Institute of Mining of the Siberian Branch of the USSR Academy of Sciences formulated for the first time [2] the traffic equations, which allowed evaluating how the location of freight shafts affect overall transportation costs.The equations proceeded from an orthogonal metric of underground traffic streams over the deposit area:

The article addresses the open pit mining of lightly pitching coal below different surface topography. Based on the analysis of the effect exerted by highwall angle on the current stripping ratio, suggestions are made on possible improvement in the open pit mine performance and extension of its life by changing the slope angle of the open pit highwall.

The main elements of the underground method of mineral mining are, of course, mine werkings by means of which there is effected a manifold technological complex: access to the mineral, its working, transport, supply of energy and materials, etc.It has been found that, despite this technological variety of functions, a network of mine workings is formed mainly on the basis of the transport characteristic of each particular mine field [1]. This characteristic takes account of the dimensions and configuration of the mine field, the volume (or weight) of mineral and its distribution over the field, and~finally, the metric* of the transport planes.In general, any underground mi~ral mining technology can be represented on three transport planes: in the plane of occurrence of the mineral (Pai}; in the plane of concentration of the haulage levels (PI~j); and in the plane of the bad-raising mine shafts (PTn).The presence of these three planes, each of which has its own technological metric (M w M 8, MT), shows that the mine field as a whole cannot be regarded from the aspect of a single metric. A rare exception will clearly be the case in whichi.e., when both the output shaft and the network of transport workings lie in the plane of occurrence of the mineral. However, even Eq. (1) is not suf~cient for the technological metrics Mcc M B, M 7 to be identical over the whole mine field. For instance, the metric of coal hoisting shafts (Ivl 7) is linear and very simple ( Fig. 1): M v (T O , H) and :~d.,, (a, b) --ha 4-h o _ Hand for this reason it will be identical with metrics M a and M/3 exceedingly rarely even with condition (1).The metric Ma(c~*, hue, h e, I ) is determined by the various conditions of occurrence of the mineral and the technological parameters otea large number of systems of working.The metric MIS(•*, lcc' I, L, Lcr) is the metric of the transport (concentration) horizons or in other words the metric of the network of opening-up workings. We found that in multihorimn working of coal or ore deposits the most suitable metric M B is rectangular (orthogonal) (