BASIC PRINCIPLES OF MINE SURFACE DESIGN

Candidate of Technical Sciences, Associate Professor A. T. Martynenko.

1. Necessary Structures and Their Purpose

For servicing the production process—the delivery of the mineral and its transportation on the surface—every mine must have a whole series of mining-engineering and auxiliary structures that perform specific functions, ensuring uninterrupted transport of the mineral from the shaft to the place from which it is shipped to the consumer.

If we consider a number of modern mines or ore mines that are the best equipped technically, we will notice that the list of structures at mines remains, in the main, almost constant, while the structures themselves, in most cases, differ only in size depending on the production capacity of the mine. Only in certain cases, owing to the nature of the mineral or to climatic conditions, does it become necessary for mines to have additional structures (washeries, concentrating plants, calorifier installations, etc.). Thus, for example, if we take an engineering structure—a railroad loading bunker—then its capacity must be determined above all from the condition of the daily productivity of the mining unit; consequently, its construction volume will also differ for two mines with different outputs. Likewise, in certain cases it may be necessary for a mine or ore mine to have a washery or concentrating plant.

Thus, at every mine we must have a certain minimum of mining-engineering structures and buildings necessary for servicing the production process of delivering the mineral.

On the surface of mines, one must distinguish mining-engineering structures, which include: headframes above shafts, trestles, bunkers, mineral storage yards, structures for waste-rock dumps, and mining-engineering buildings—the headhouse, hoist-engine buildings, workshops, boiler house, combine, electrical substation, compressor house, fan building, etc.

Mining-engineering surface structures and buildings, according to the nature of the functions they perform, are divided into 3 main groups:

Group I. Structures serving for the movement of minerals and rock brought out of the mine, up to the dispatch of the former by railroad. This group may include: the headframe, the pithead building, the building of the hoisting machine, the sorting plant, trestles, the coal storage yard, bunkers, structures for waste-rock dumps, and railroad tracks.

Group II. Auxiliary structures ensuring an uninterrupted production process at mines. These may include: the electrical substation, workshops, compressor buildings, warehouses for auxiliary and lubricating materials, the locomotive depot, the fan building, the timber yard, calorifers, etc.

Group III. Structures serving workers on their way to work. This group includes: the bathhouse and changing facility, covered trestles for the passage of people, and partly the boiler house.

Thus, on the territory of the mine yard we have three principal groups of mining-engineering structures and buildings, united by the common principle of the purpose of each separate group in the production process; this is of great importance when placing all the structures in the general surface plan of the mine.

2. Factors Determining the Layout of Mine Surface Facilities

The combination of the individual objects of mining-engineering structures into a general surface plan is called the surface layout.

Under the conditions of socialist construction, when organizing the surface facilities of mines, in addition to technical factors, it is necessary strictly to observe the directives of the Party and the Government concerning care for the people engaged in production, and the socialist order of mineral extraction. This provision introduces a whole series of special prerequisites into questions of planning the surface of mines, both in new mine construction and in the reconstruction of existing mines. Herein lies the principal, fundamental difference in the organization and construction of the surface facilities of mines in the USSR as compared with capitalist countries.

Let us consider the technical factors influencing the character of the layout of mine surfaces.

a) Terrain Relief

Considering the principal coal regions of our Union, we shall note that for the most part they are situated in dissected terrain; this should be especially noted with respect to the Kuzbass. This causes certain difficulties in selecting a sufficient construction site for the territory of the mine yard, since the terrain relief very often influences the choice of the location for laying out the mine, owing to the impossibility of bringing in access tracks—

Fig. 1.

Fig. 2.

mines. Therefore, in determining the location for the construction of a mine according to mining conditions, it is not always possible at the same time to satisfy the requirements of rational surface construction. As an example one may cite the Stalin Mine and 3–3 bis in Prokopyevsk.

In addition, the rugged terrain in the area of the mine-yard territory will undoubtedly entail additional expenditures for the construction of drainage facilities, which must always be borne in mind when planning the construction site.

b) Method of opening and type of mine.

The natural-geographical conditions of our coal deposits, with the highly varied occurrence of the seams, make it possible to open a deposit by various methods, which determines the type of mine. Thus, for example, a deposit may be worked by open-pit operations, by an adit, by an inclined or by a vertical shaft. With any of the listed types of mine, their surface will differ sharply from one another. Thus, for example, if we compare the surface of an inclined mine and a vertical one, we shall note that in the first case the headframe is most often located at the end of an inclined trestle. There is no shaft-head building as such; it is replaced by a receiving platform located at the end of the trestle. Therefore, the character of the arrangement of individual groups of technical structures for a vertical and an inclined mine will correspondingly differ from one another. A particularly great difference will be observed when a deposit is opened by adits.

c) Method of hoisting.

The mineral can be hoisted to the surface by means of ordinary cages, in mine cars, by tipping cages, and also in skips. For each of the indicated hoisting vessels it is necessary to have special receiving devices on the surface. If, let us say, the mineral is hoisted to the surface in mine cars (Fig. 1), then in this case it is necessary to have a sufficiently large receiving platform of the shaft-head building for laying out the runaround tracks on it. It is quite another matter if the mineral is delivered to the surface by skips (Fig. 2); in this case there is no receiving platform in the full sense of the word, but there are receiving hoppers, from which the mineral, by means of transport devices, is transferred to bunkers or storage yards.

Consequently, in the first case the receiving platform of the shaft-head building and the building itself will have large dimensions; moreover, the building will be located above the mine shaft. With skip hoisting, the shaft-head building will be of limited dimensions, in the form of receiving hoppers, and may be located next to the shaft-head headframe. This is the first observation concerning the influence of the method of hoisting on the type of shaft-head building. Secondly,

with different methods of hoisting, the nature of the organization of moving the mineral to its loading into railway cars will be different, and consequently the mutual arrangement of the principal group of technical structures will also be different.

c) Annual output of the mine.

First of all, the annual output of a mine may necessitate the presence of two, or even three, shafts (hoisting, auxiliary, and ventilation), as is the case in most newly built large mines. If the shafts—the hoisting and the auxiliary—are located at a short distance from one another and have a single hoisting system, then such shafts are united by a common receiving platform. As an example one may cite the “Proletarian Dictatorship” mine of Sevkavugol, which has 2 shafts with cage hoisting, united by a common receiving platform. In this case a single fail-safe system of transport-mechanical equipment for the receiving platforms of the pithead building is obtained. Recently, hoisting shafts in most cases have been equipped with skip hoisting, while the receiving platform of the auxiliary shaft is always located at ground-surface level and is equipped with gravity tracks. The combining of such shafts should not occur in practice, since in this case each shaft constitutes an independently operating link in the general production process. Consequently, the annual output of a mine, in a rather complex dependence, affects the character of the layout of the mine surface.

d) Number of grades and brands of coal.

This factor will mainly affect the loading-and-storage facilities of mines. Thus, for example, when two brands of coal are hoisted that are not subject to mixing, it is necessary to have separate receiving devices on the surface, calculated in such a way that during loading into railway cars both brands of coal can be loaded simultaneously. This is very important in route shipment of freight, i.e., when groups of cars making up a train, loaded from one mine, proceed without any shunting work at intermediate stations to the consumer. Thus, in this case, and also when there are different grades of coal, it is advisable to arrange the loading bunkers with their longitudinal axis perpendicular to the railway tracks; this makes it possible, with a smaller amount of shunting work on the loading tracks, to load different grades and brands of coal.

When the mineral is delivered in ordinary sequence, it is more advisable to arrange the bunkers along the loading tracks, since in this case there will be a minimum of shunting work required for placing cars under the loading points.

e) The type of surface transport.

The most favorable influence on the character of the arrangement of mining-engineering structures will be exerted by broad-gauge railway transport, provided that suitable terrain is available for it. The low cost of transporting bulk freight over access railway tracks differs very advantageously from other modes of transport; moreover, with railway transport there are always fewer transshipment operations than with another mode of transport, which will have a favorable effect on the quality of coals, especially graded coals. For example, the “Uralo-Kavkaz” mine of the Sorokinsky Trust in the Donets Basin is 1.5 km from the main railway line. The mine is situated in difficult relief conditions, which complicate the laying of a railway line to it. Coal is transported by an aerial ropeway, as a result of which one extra transshipment operation has appeared, causing the construction of an additional structure.

In difficult relief conditions, when the cost of bringing railway lines to a mine rises considerably, or in built-up areas, aerial ropeways sometimes provide an advantageous solution. Such roads are most often used when the principal consumer of coals or of other minerals is located near the mine.

In conclusion, it must be noted that, in addition to the factors listed, which basically determine the character of the layout of the surface of mines, climatic conditions and the degree to which mines are supplied with empty cars will undoubtedly have great significance. On the other hand, the heterogeneous type of rolling stock, the differing carrying capacity of cars, and their poor suitability for transporting bulk freight still do not have an entirely favorable influence on the character of the mine surface, making it necessary for mines to have large-capacity storage yards or loading facilities adapted for operation with cars of different types.

3. Features of the Surface of Mines in Western Europe and the USA

Considering the surface of the best-equipped mines of Western Europe and America, we observe a difference in the types of structures in these countries. Whereas in Western Europe all surface structures are distinguished by their bulkiness and complexity, in the USA they are distinguished by considerable simplicity and lightness. Thus, two main types of mining-engineering structures at mines may be established:

a) American—the light type.
b) Western European—the heavy type.

These two basic types of surface mining-engineering structures, in their historical development, took shape under

under the influence of many causes, both natural geological-geographical and socio-economic. In particular, considering the local conditions in which American mines are located, we note that the climate there is most favorable: the average temperature in the winter months ranges from 3–7° below zero. Therefore, the question of heating mine structures almost never arises.

In addition, the more favorable conditions of occurrence of deposits make it possible to work out mines more rapidly and to have lighter and simpler mine structures.

Considering the conditions of the coal regions of Western European countries, where the climatic conditions, as well as the conditions of occurrence of minerals, are incomparably more difficult than in America (winter lasts up to 3 months and with temperatures down to −18°; the seams are of insignificant thickness and lie at greater depth), one may state that under such conditions heavier structures with a longer depreciation period are naturally required.

The following basic principles underlie the arrangement of the surface of new mines in the USA¹:

1. Strict separation of the freight flow and auxiliary functions in the shaft.

2. The height of the headframes of a hoisting shaft is designed with the calculation that, during hoisting, the mineral acquires sufficient height for subsequent movement along inclined planes under its own weight, up to loading into railway cars. If this cannot be achieved, belt conveyors are used predominantly for transporting coal on the surface.

3. For auxiliary shafts the receiving platform is made at ground-surface level, from which people and auxiliary materials are lowered into the mine. The headhouse of an auxiliary shaft is made of limited dimensions both in plan and in height.

4. The mineral is loaded into high-capacity self-unloading cars by means of inclined chutes, telescopic tubes, or loading booms. At the start of mine operation, rolling stock is supplied in sufficient quantity, which in many cases makes it possible not to arrange loading bins at the mines.

5. Owing to the presence of automatic brakes on all rolling stock supplied to the mines, shunting during loading is reduced to a minimum. Car shunting is carried out according to a straight-through system by means of inclined planes or capstans.

6. Rock, as a rule, is not brought to the surface.

Fig. 3.

Fig. 4.

The rock selected from sorting belts is transported in railroad cars for backfilling and, in rare cases, goes to flat dumps.

In concluding the general characterization of the surface facilities of American mines, it is also necessary to note the complete mechanization of labor-intensive processes.

In contrast to American mines, Western European mines to a considerable extent do not have a strict separation of the functions of hoisting machines. Often two hoisting devices are installed in one shaft; these handle the delivery of the mineral, as well as the lowering of people and auxiliary materials.

In most cases, the mineral is delivered to the surface in mine cars by multi-deck cages.

The use of multi-deck cage hoisting necessitates the construction of headhouse buildings of considerable size, with numerous haulage tracks on the receiving platforms, which constitute a system of self-acting loops equipped with duplicate sets of mechanisms (pushers, height compensators, tipplers, etc.) to ensure uninterrupted operation.

Characteristic, in particular, of the surface facilities of German mines is the use of tower-type headframes, i.e., with the hoisting machine located on the headframe tower. This is apparently explained by the fact that the mines are situated in very built-up areas. The same must be noted with regard to loading stations, where, owing to the built-up nature of the locality, movable transfer tables (Fig. 3) have become widespread instead of ordinary switches; their use provides a considerable reduction in the length of loading stations. In 1930, at Shakhtstroy, a design was prepared for a railroad loading station for the Shcheglovskaya mine of the Kemerovo district of Kuzbassugol (Fig. 4), using a movable transfer table. Despite the considerable cost of such an installation, under cramped conditions the movable transfer table provides an excellent solution to the problem.

4. Layout of the Surface Facilities of Mines in the USSR.

New mine construction in the field of surface facilities in our country has been based primarily on the experience of Western European and American engineering, taking into account the socio-economic characteristics of our country.

The best examples of foreign practice in the field of mine surface facilities require the introduction of a whole series of corrections, on the one hand those inherent in our socialist conditions under the planned development of the economy, and on the other hand those due to the specific geological, geographical, and climatic conditions of our coal basins.

In the first years of designing new mines (1927–28), a course was adopted toward the Western European surface layout, which was explained by a certain similarity in the natural-geographical conditions of the Donets Basin.

Our climate is still more severe than in Western Europe: the temperature in the Donbas, not to mention the Kuzbas, often reaches 20°, and winter lasts 3–4 months. Therefore, judging by the natural conditions of seam occurrence in the Donbas, it seemed that the surface structures used in Western Europe were best suited to the conditions of this basin, all the more so since our socialist economy provides for a careful attitude toward reserves, which makes it possible to extend the service life of mines.

Much later, owing to the fact that in the designs for new mine construction a course was taken toward a centralized surface layout, with intensified development of deposits, the Western European type of surface structures (heavy constructions) began to be displaced by a lighter, simplified type of surface structures characteristic of American mines.

Thus, for example, the construction of mine surfaces in the Kuzbas has been adopted mainly according to the type of American mines.

It has already been mentioned above that the “surface” of the best foreign mines, for the USSR, requires the introduction of a whole series of corrections that take into account the specific conditions of our coal basins, as well as the particular features of the development of a planned economy under socialist construction.

The special concern of the Party and the government for creating the most favorable cultural and everyday working conditions for workers is inherent only in our socialist economy. Therefore, alongside industrial construction, new socialist cities are being erected, and old, dirty, poorly developed workers’ settlements are being transformed in an entirely new way into genuine models of socialist culture.

In considering in detail the distinctive features of the surface arrangement of our mines, it is necessary to note the following: the presence of emergency stockpiles at mines in the USSR is determined by severe climatic conditions, frequent snowdrifts, river floods, and a temporary shortage of a mobile specialized fleet of railway cars for transporting bulk freight.

Climatic conditions and natural disasters (drifts, river floods, etc.) have a lesser influence on the loading of mine stockpiles, since the accumulations of coal obtained as a result of this cause can be hauled away over a long period of time. The general shortage, at the present moment, of a mobile fleet of railway cars proved dominant in this respect. Thus, for example, in the Donbas in 1930/31 the supply of cars to mine administrations fluctuated between 60 and 94%. Separately, for anthracite mines, it averaged 75%, while in winter it was 50% and even fell to 32%. In the Kuzbas, in the Leninsky district, the average requirement was

in rolling stock for 1934 was met by 75%, for the first quarter of 1935 by 80.9%,¹ for 1936 by 85.1% of the loading plan, and for 1938 by 87.5%.

In connection with the annual growth in the transportation of bulk freight, there was a general shortage of a specialized fleet of railway cars, which was also reflected in the coal industry. The variety of rolling stock supplied to the mines causes certain technical difficulties in the arrangement of bunkers, i.e., bunkers must be arranged with such calculation that any type of car can be loaded from them. At present, it must be said that the provision of mines with rolling stock for hauling out the mineral is quite satisfactory. True, irregularity in the delivery of cars to the mines still occurs even now.

Thus, in the construction of new mines during the period of the first and second five-year plans, we should have had higher-capacity storage facilities of the bunker and silo type, representing, on the one hand, means for mechanizing the loading of trains consisting of different types of cars, and, on the other, a means of mitigating the unevenness of car delivery, while at the same time providing emergency stockpiles at the mines.

In designing new mines at the present time, the mechanization of the loading-and-storage operations is being solved in somewhat different ways,² arising from the conditions of the modern operation of railway transport for hauling out the useful mineral.

Unlike foreign practice, at our mines, in most cases, rock is brought to the surface. Therefore, in designs it is necessary to provide places for dumps of waste rock, which by the end of a mine’s service life reach considerable dimensions.

In Kuzbass at present, at newly designed mines, as well as at some existing ones, the use of rock for stowing is envisaged. Therefore the surface of such mines is distinguished by an additional stowing operation, which must be coordinated in the general master plan of the mine surface.

5. Plan for the Arrangement of Technical Structures

All mining-engineering structures and buildings are located around the mine shafts in one order or another, forming the general surface plan of the mine.

The nature of the mutual arrangement of structures on the surface of mines will be influenced chiefly by the terrain relief,

fire-safety conditions, the protection of buildings from collapse, and also, in recent times, in designs for new mines, great attention has been paid to the architectural treatment of the entire mine-yard territory as a whole.

For the most proper placement of structures and buildings on the surface of mines, it is first of all necessary to establish the basic functional relationship among the individual groups of structures.

Thus, structures serving the movement of the cargo issued from the mine must be located near the mine’s hoisting shaft, obeying the strict sequence of the sorting process while maintaining an unchanged direction of the freight flow.

Structures serving the mine workers must be arranged with such calculation that the workers, having passed through all the required stages by the shortest route, enter the mine.

Auxiliary technical structures—workshops, warehouses, etc.—must be located so that the movement of loads within the territory of the mine yard constitutes a strict system of separate consecutive flows.

Upon a detailed examination of the surface plans of mines, we noticed that at one mine all the structures are arranged in the form of a quadrangle, at another—in the form of an elongated rectangle, and under especially constrained local relief conditions all the structures are stretched into a single line near the railroad loading tracks. In general, the placement of structures on the surface of mines displays great variety.

Until the present time, the surface of a mine represented an unformed, unorganized territory. Surface planning followed the technological process, subordinating itself to the requirements of underground work, without regard to local conditions and with a complete absence of any architectural forms. As a consequence, the surface of such mines is distinguished by the extreme scattering of buildings over a considerable territory, by the blurred boundaries of the mine, by the absence of a façade side strictly maintained in style, by an unsuccessful mutual placement of structures in relation to workers’ settlements, etc.

New mines at the present time, in terms of the treatment of the surface, are being built in an entirely new way. More and more, elements of organization and improvement appear at new mines; in its treatment the mine territory begins to approach a plant or factory, which undoubtedly has a beneficial influence on labor discipline, organization, and labor productivity.

As is known, on the territory of a mine there are structures connected with the emission of gases and the formation of dust, such as: all kinds of storage and loading devices, concentrating mills, waste-rock dumps, etc.; these must be set apart into a special group and located on the territory of the mine yard

taking into account the prevailing winds. Structures not directly connected with the production process are grouped on the territory of the mine yard, forming the façade sides of the enterprise; they should face the workers’ settlement, as, for example, the combine, the power station, the machine building, etc. It is desirable to locate railway tracks with the calculation that workers, when going to the mine, will not have to cross them—which, incidentally, is not always practically feasible.

Thus, when drawing up the general plan of the mine surface under our conditions, it is not enough to satisfy technological, structural, and economic requirements alone; it is also necessary to give architectural form to the “surface” as a whole. An example of this may be one of the variants of the technical design of a modern mine, shown in Fig. 5.

6. Temporary structures on the surface and their coordination with permanent ones.

The driving of mines may be organized both with permanent and with temporary mining-engineering structures and their equipment. In order to choose one or the other system, it is necessary to compare the cost and the time required for driving under the given technology of driving operations.

The principal decisive factors in choosing one system or the other will be:

1. Type of mine. Generally speaking, the type of mine follows from the geological conditions of the deposit on which it is proposed to employ it; but in the sense in which we use it, the determining influence will be exerted chiefly by the depth of the mine, its service life, and the time required, with the present technology of driving operations, for driving the mine.

Shallow mines with timber supports, with wooden permanent structures on the surface, and with a service life of up to 10–12 years will obviously require little time for driving (4–5 months). Therefore such mines are more advantageously driven with permanent mining-engineering structures and equipment (abroad we observe the driving of mines to depths of up to 800 m with permanent equipment).

Deeper mines with a long service life, with concrete supports, with metal headframes, and with concrete or stone surface structures will require a longer period for construction (for large mines, about 2 years¹); therefore it is more expedient to drive such mines with temporary equipment and structures.

1. Construction season. As is known, in winter the pace of construction decreases because of severe climatic conditions. In Kuzbass, the construction season at full rates—

¹ Maximum—one to one and a half years for small and medium mines.

Fig. 5.

BOUNDARY OF THE CONSTRUCTION SITE

Fig. 6.

lasts 6–7 months, which, of course, is insufficient for the erection of permanent structures, while constructing them in heated enclosures increases the cost by approximately 20%. Therefore, for deep mines with a short construction season, by the beginning of sinking it is possible to build temporary light-type structures, and during the sinking period (up to 2 years), by the time it is completed, all permanent structures can be erected.

1. The choice of equipment is greatly influenced by the availability of individual standard wooden structures, which have recently become widespread in new mine construction (standard sinking headframes, hoist-house buildings, etc.). This makes it possible to erect temporary structures quickly, and also to reuse them 2 to 3 times at new sinking operations with only minor renewal.

2. Despite the special government decree prohibiting construction without completed working drawings, in practice this still occurs. The experience of previous years has shown that very often, when design was not comprehensive, during the sinking period the final plans for mine surfaces were repeatedly corrected (the T. Stalin Mine in Kuzbass may serve as an example), which during the construction period led inevitably to alterations and relocation of individual structures; there were even cases when temporary structures were erected on the sites of future permanent structures.

Thus, the existence of a final design for the general plan of the surface, coordinated with the temporary structures, is of great importance, since any alterations, on the one hand, lengthen the construction period and, on the other, entail an inevitable increase in the cost of construction as a whole.

By the beginning of mine sinking, alongside the erection of temporary structures it is also necessary to begin construction of permanent facilities that can be used for the purposes of sinking. Thus, for example, the building of the permanent mechanical shops, by virtue of its volume, can be used to accommodate the temporary plant and shops; the same may be said with respect to other permanent structures.

On the other hand, very often in the first years of mine operation temporary structures are used whose specific cost, as a percentage of that of permanent structures, ranges approximately from 4 to 6.

Consequently, temporary structures on the mine surface must be coordinated in the overall general plan, which makes it fully possible to replace them with permanent ones by the time the mine is put into operation. However, it is sometimes impossible to avoid complete coincidence of the locations of temporary and permanent structures. In such cases it is necessary to take into account the sequence of erection of permanent structures and of the possible demolition

temporary as they are used. This circumstance must always be kept in mind, since such objects as the buildings for sinking hoisting machines and winches can be located only at a quite definite distance from the shaft axis, and their mutual arrangement does not always admit of various modifications. Examples of the arrangement of temporary buildings and structures may be found in the Shaft Sinker’s Handbook.

7. Planning the Territory of the Mine Yard and Drainage Devices

Grading work in the construction of a mine is of enormous importance. During the sinking of the shaft, of the mine yard, and of the workings around the shaft, it is advisable to use the rock brought to the surface immediately for grading. In cases where the rock cannot be used for grading work, it must be concentrated at the site of the future waste-rock dump, since otherwise this may cause additional expenses. Thus, for example, at mine No. 8-a in Gorlovka the shifting of rock cost 25 thousand rubles, whereas this rock could have been used immediately for dumping the railway embankment of the access track.

A similar mistake also occurred in the Kuzbass during the construction of the Kapitalnaya 1 mine in Osinovka, where the rock dump still makes it impossible to expand the emergency storage yard.

Thus, in order to avoid repeated work, the rock brought out during sinking must be taken into account in the general grading planned for the construction of the mine.

In flat terrain, grading work is reduced to small fills and cuts of earth until a horizontal site is obtained. In this case there is almost always enough soil obtained when digging the pits required for laying the foundations under the technical structures. Therefore, rock from sinking cannot be used and must be hauled to a dump or to the embankment of future access roads.

In rugged terrain, grading work reaches significant dimensions, especially when the entire territory of the mine yard is graded to one common elevation.

To reduce the amount of grading work, it is advisable to arrange terraces, i.e., separate groups of technical structures and even individual buildings should be placed on sites whose grading is carried out in accordance with the terrain and in general coordination with the controlling elevations of the technical structures: the rail heads of the railway tracks, the receiving platform of the headframe building, the position of the axes of the sheaves of headframes, etc.

The terraced method of planning the territory of the mine yard may require additional arrangements for strengthening

of slopes and even the construction of retaining walls of considerable length; moreover, almost always with this method of grading the drainage structures become more complicated in structural terms, and the drainage of the mine-yard area acquires urgent importance. Therefore, when grading by terraces, it is always necessary to bear in mind the possibility of providing drainage over the entire territory of the mine yard.

The main group of technical structures serving for the movement of the load issued from the mine (the headframe, the pithead building, the preparation plant, trestles, bunkers) must be located on one terrace, the design elevation of which is directly dependent on the elevation of the rail head of the railway loading track. A mismatch of the above-mentioned elevations may cause an increase in the height of the technical structures, or, at best, an increase in the length of the transport galleries, which is undesirable, since it inevitably entails a considerable increase in construction cost.

Structures serving the auxiliary freight flow must be planned with such a calculation that there will be no obstacles to the normal operating conditions of transport within the mine yard (narrow-gauge tracks and highways). It must be said that the terraced method of grading limits the choice of directions for auxiliary freight flows on the territory of the mine yard.

As for the other structures, they may be located on separate sites graded to an elevation with a minimum amount of grading work. At the same time, fire-access approaches to them must be provided.

As was already mentioned above, the entire construction site of the mine-yard territory must have a system of drainage devices protecting the structures from water flowing in from nearby slopes of the terrain, and also within the territory of the mine yard from storm water.

During snowmelt or heavy rains, water flowing from the slopes of the terrain toward the mine-yard territory may have a destructive effect. Therefore, enclosure of the mine territory is mandatory—by a system of so-called upland ditches.

The dimensions of upland ditches are determined by the inflow of water from a part of the earth’s surface called the basin, from which water can flow to the construction site.

In Fig. 6 the relief is given of the terrain adjoining the boundary of the construction site. To determine the basin of water inflow, we find the watershed lines abA, Cd, by which we determine the area of the basin with a planimeter.

Water flows along the drainage lines of the thalwegs; the velocity of its inflow depends on the length and slope of the ravine. The slope

Inset: Approximate isolines. Coefficient \(C\).

Visible map labels: Arkhangelsk; Ust-Sysolsk; V.-Ustyug; Vologda; Vyatka; Perm; Izhevsk; Ufa; Orenburg; Uralsk; Kazan; N.-Novgorod; Moscow; Yaroslavl; Kostroma; Vladimir; Tver; Leningrad; Novgorod; Pskov; Vitebsk; Smolensk; Mogilev; Kaluga; Ryazan; Tula; Orel; Chernigov; Kiev; Poltava; Dnepropetrovsk; Kherson; Simferopol; Novoross.; Stavropol; Astrakhan; Saratov; Penza; Tambov; Voronezh; Kursk; Kharkov; Rostov-on-Don; Stalingrad.

Isoline values visible on the map include: \(6\), \(8\), \(10\), \(12\), \(14\), \(16\), \(18\), \(20\), \(22\), \(24\).

Fig. 7

of the main thalweg is the ratio of the difference in elevations of points \(AA_1\) to the length of the thalweg:

\[ i_{\text{av}}=\frac{A_1-A}{L} \]

A more accurate method for determining the average slope of the basin takes account of the following expression:

\[ i=\frac{\sum b_n L_n i_n}{\sum b_n i_n}, \]

where \(b_n\) is the width of secondary thalwegs;
\(L_n\) is the length of the thalwegs;
\(i_n\) are the uniform slopes of thalweg sections.

This formula should be used in cases where the longitudinal slopes of the individual sections of the thalweg differ greatly.

The greatest inflow may be from rainstorms (or during rapid snowmelt), the intensity of which is measured in mm of precipitated water per unit time.

The quantity of inflowing water in \(m^3/sec\) is determined by the formula:

\[ Q=C\alpha F, \]

where \(F\) is the basin area in \(km^2\);
\(C\) is the climatic coefficient, determined from a map of isolines (Fig. 7), and characterizes the intensity of precipitation falling in the given locality;
\(\alpha\) depends on the length and slope of the basin; its values are taken from the data in Table 1.

Value of the coefficient \(\alpha\) for \(C>12\) Table 1.

A reduction in the runoff of storm waters may be allowed up to 50% in highly permeable soil, i.e., in sandy soils up to 1 meter thick, and in wooded terrain—by 20%. In all other cases, no reduction in the inflow of water may be allowed.

The cross-section of drainage ditches is determined from the condition of the greatest inflow, determined by the above formula.

Conclusion

The surface equipment of modern mines constitutes a complex outfitted with the most advanced mechanization, accounting for up to 30% of all capital expenditures in the total cost of construction.

Therefore, the design of the surface of such mines is of exceptional importance for the national economy and represents a highly complex and responsible task for the engineer.

The wealth of experience in mine construction accumulated during the first two Stalinist five-year plans has forged a cohort of specialist design engineers—mining engineers of a new profile—working exclusively in this field. This is entirely understandable, since mines equipped with advanced modern technology, both in construction and in operation, require specialized knowledge, which the old higher school under the capitalist system, of course, could not provide.

Under the plan for the development of the national economy in the third five-year plan, extensive construction of small and medium-capacity mines is to be undertaken; for these, design organizations must immediately begin developing rational types of equipment for surface facilities, taking into account the comprehensive mechanization of all work processes both underground and on the surface.

1. A. T. Martynenko, “Methods of Mechanizing the Loading Operations at Leninsk.” Journal of the Coal Industry of the East, No. 9, 1935. ↩↩

2. A. T. Martynenko, “Paths of Development of Loading-and-Storage Operations at Kuzbass Mines.” Mining Journal, No. 5, 1938. ↩