On the Issue of Driving Raise Workings in the Mines of the Prokopyevsk–Kiselevsk District of Kuzbass

O. D. Alimov, I. A. Ushakov, D. N. Malikov

The mining of steeply dipping seams in Kuzbass is associated with the driving of a large number of raise workings (furnaces). Thus, in 1956, in the mines of the Prokopyevsk–Kiselevsk district alone, about 400 km of such workings were driven, including more than 270 km under shields.

Beginning in 1944–45, in the driving of raise workings in the mines of Kuzbass, SBSh-3u core-drilling machines came into wide use, and from 1948 onward, LBS-2 machines. The use of these machines provides for mechanized driving of boreholes 300–400 mm in diameter when drilling, and 500–850 mm when reaming. However, a borehole that has been drilled and then enlarged to a diameter of 850 mm is, in most cases, not a completed raise working suitable for operation. Usually the boreholes are subsequently enlarged with jackhammers or by the drilling-and-blasting method to a square cross section of 1.5–2.25 m². Workings driven in this way are used without support under favorable conditions, and in other cases are supported with timber.

The large angle of inclination of the axis of the working to the horizon (50–90°) and the absence of means for comprehensive mechanization account for the extremely high labor intensity of driving these workings. The work of a furnace drivage miner may be classed among the most difficult categories of underground work. Working in confined conditions, with the face located overhead, the drivage miner is exposed to the danger of falling down the working. Under such conditions, the rate of driving supported raise workings with a cross section of 1.5 m² is 2.5–3 running meters per shift, or 190–225 running meters per month with three-shift brigade work. Thus, at present the rate of driving raise furnaces is considerably lower than the rate of driving crosscuts by mechanized methods [1, 2, 3], despite the fact that the crosscuts have a cross section 2–4 times greater than that of the furnace. At the same time, the cost of driving 1 running meter of a furnace is often equated with the cost of 1 running meter of a crosscut.

Low rates of driving raise workings hinder the deployment of the longwall face, create strain in the organization of planned coal production, since the driving of raises basically completes the entire complex of preparatory work in a stoping area. The large volume of work involved in driving raise workings, the low rates, and the high labor intensity of their driving require a comprehensive examination of questions connected with the parameters of raise workings, the technology of their driving, the mechanization employed, and the organization of work. Meanwhile, until now due attention has not been paid to the study of these questions. Therefore the authors believe that investigations of certain questions in this direction, carried out by the Tomsk Polytechnic Institute* jointly with KuzNIIUI, will to some extent contribute to solving the problem of comprehensive mechanization of driving raise workings.

In the present work, the experience is summarized and an analysis is given of the existing methods of driving raise workings in the mines of the Prokopyevsk–Kiselevsk district; in addition, possible ways are outlined for increasing the rates of driving workings and raising the labor productivity of the drivage worker.

According to their purpose, raise workings are subdivided into coal chutes, timber chutes, ventilation raises, travelways, etc. In most cases one and the same working serves simultaneously (or successively) as a travelway, ventilation raise, and loading working. Under the shield system, for example, four raises are driven for each shield, of which the two middle ones serve for lowering coal, while the two outer ones are used as travelways, coal chutes, and ventilation raises.

According to the method of driving, all raise workings may be divided into three groups:

1) workings driven by a fully mechanized method (by drilling and reaming holes to a diameter of 850 mm);

2) workings driven along pre-drilled holes;

3) workings driven without preliminary drilling of holes (through solid coal).

In the last two groups, coal breaking is carried out by the drilling-and-blasting method or with a pneumatic pick; moreover, workings are driven both with support and without support.

The application of one or another method of driving raise workings depends on mining-engineering conditions. In gas-bearing seams, coal breaking is carried out with a pneumatic pick; in

* Report of the Department of Mining Machines and Mine Transport of the Tomsk Polytechnic Institute: “Investigation of Means and Methods for Driving Raise Workings in the Mines of Kuzbass,” 1957. Archive collection of KuzNIIUI.

in the remaining cases—by the drilling-and-blasting method. Through solid coal, workings are driven under conditions of disturbed seams, when drilling boreholes is not possible. In mining seams on the upper levels, where no significant rock pressure is observed, and also in strong and stable coals of the lower levels, unsupported workings have become most widespread. Often under these conditions boreholes enlarged to a diameter of 850 mm by the SBM-3u machine are used as completed workings, as coal chutes and ventilation raises. Manways are supported in all cases and under any conditions. With the exception of boreholes, raises of all purposes are for the most part made with a clear cross section of 1.5 m². In accordance with the current technology of extraction work under shield supports, the driving of raises must be carried out at a certain distance from the footwall side of the seam. Depending on the thickness and dip angle of the seam, this distance ranges from 0.5 to 3.0 m.

Special-purpose workings (inclined raises) are made with a clear cross section of up to 4 m². The share of raise workings with a cross section greater than 1.5 m² for all mining systems in the district does not exceed 8%.

The table gives data for 1956 on the use of various methods of driving raise workings under shield supports in the mines of the Prokopyevsk-Kiselevsk district. From the data in Table 1

Table 1

it is evident that more than 96% of the workings were driven from boreholes and only 4% through solid coal. 14.6% of the workings were used in the form of boreholes 850 mm in diameter. Enlargement of boreholes to a square section in most cases was carried out by the drilling-and-blasting method, and only 7.8% by jackhammer.

The proportion of workings driven with support was 49%; moreover, it may be assumed that, as mines become deeper, owing to the increase in rock pressure, their proportion will grow. Thus, in 1956 at the Koksovaya 1 mine, which conducts mining operations on the third and fourth horizons at a depth of 200–300 m, 95% of the chutes under shields were driven with support, of which 89.4% were on the third horizon and 97.3% on the fourth. At the Koksovaya 2 mine, when seams are being worked on the fourth horizon, all workings under shields are driven with support. The support serves both to protect the workings from destruction by rock pressure and to protect them from being washed out by the flow of coal being passed through.

Wooden posts with a diameter of 12 to 20 mm are used as support in raise workings; they are laid around the perimeter of the working in the form of a crib. For supporting 1 m of working, 0.5–0.7 m³ of timber is consumed. For convenient connection in the lock, the support posts are processed on special notching machines on the mine surface. The technology for manufacturing and installing posts of the same size in the working is simpler than for posts of different lengths. Therefore, driving workings of square cross section is more rational than driving rectangular and trapezoidal ones.

The service life of most chutes is short (2–4 months), and therefore some of the posts are often reused. Significant shortcomings of timber support are its considerable cost, insufficient yielding capacity, and the possibility of chutes becoming clogged when dismantled crib posts are lowered through them during shield operation.

Experiments by KuzNIUI on shotcreting chutes under conditions of considerable rock pressure have not yet yielded positive results. Owing to the absence of yielding capacity, the shotcrete, applied in a thin layer to the walls of the working, cracked and crumbled. Under such conditions, anchor support also cannot ensure normal maintenance of the workings and does not protect them from being washed out by the flow of coal being passed through.

As already noted, the overwhelming majority of raise workings in the district’s mines are driven along predrilled boreholes. The presence of a borehole ensures ventilation of the face by means of the general mine depression, determines the direction of the working being driven, reduces the number of crosscuts between chutes, and improves the working conditions of the drivage workers.

It should be noted that in recent years there has been a tendency toward increasing the intensity of use of light crosscut-drilling machines LBS-2 and toward reducing the share of heavy SBM-3u machines in the work. Thus, in 1956 more than 65% of the volume of drilling work in the district’s mines was performed by LBS-2 machines. This is explained by the fact that, with the increase in the proportion of supported chutes on the lower horizons, the need to widen boreholes to a diameter of 850 mm has fallen sharply. Therefore light and bo-

The LBS-2 machines, being more convenient to service, began to be used for drilling boreholes not only from intermediate but also from main drifts, displacing the heavier SBM-3u machines.

Observations have established that the average shift output of raise-boring machines in shifts during which uniform operations were carried out—drilling, reaming, or lowering the tool—is as follows: drilling boreholes 300–400 mm in diameter, 25–30 linear m; reaming boreholes to a diameter of 500–850 mm, 15–20 linear m; lowering the tool, 50 m.

Taking these basic indicators into account, and allowing for the performance of all auxiliary operations, the average shift output of the machines should be 14–16 linear m, while the output of the drillers should be 7–8 linear m of initial (unreamed) borehole to breakthrough. However, as a result of a study of the operation of the drilling shops of three mines in the district (Koksovaya 1, No. 13, and 3–3-bis) during 1956, it was established that the actual average shift output of the drillers ranged from 3.4 to 4.6 linear m of borehole to breakthrough, i.e., half the technically possible level.

The low labor productivity of drillers is explained by the fact that they spend from 40 to 55% of all working time performing work not associated with servicing the machine at the workplace (delivering the machine and tools to the workplace, connecting electrical equipment, opening boreholes, organizational downtime, etc.). Clear organization and planning of drilling operations throughout the entire mine, as well as timely preparation of niches for machines and the streamlining of the surveyor’s service, can create real conditions for increasing drillers’ labor productivity by at least 30%.

The labor input of drilling is usually lower in those cases when longer boreholes, located close to one another, are drilled. In this case the share of work involved in transporting machines is reduced. Thus, a higher labor productivity (4.6 linear m to breakthrough) was achieved at mine No. 13, where 95% of the drilling work was performed in shield sections, which have a minimum scatter of boreholes despite their considerable length (80 m). Therefore, the share of the main operations directly connected with driving the boreholes was 57.8% at mine No. 13, and 46.3% at Koksovaya 1 mine. However, when drilling boreholes 100–120 m long, rejects increase sharply (up to 20%) because of their deviation from the specified direction. For the existing machines and drilling tools, the optimal borehole length may be considered 50 m for LBS-2 machines and 80 m for SBM-3u machines.

The cost of drilling 1 linear m of borehole, considering only the direct wages of workers at the above three mines, ranges from 12 to 18 rubles. If, however, additional monetary costs are taken into account (bonuses, night differentials, foremen’s allowances, and other

accruals to workers), the average annual cost of 1 linear m of borehole for this category of expenditures, for example, at the Koksovaya 1 mine in 1956 amounted to 26 rubles, or 15% of the total cost of the completed, timbered working.

Table 2 gives data on the productivity and cost of driving raise workings with a cross-section of 1.5 m² in the clear, under various driving methods with support. From these

Table 2

data it is seen that the actual average shift advance of the workings ranges from 2.4 to 3.0 m. The cost of 1 linear m of working in direct wages is 65–75 rubles, and with timber materials taken into account, 170–180 rubles. None of the driving methods used has substantial advantages over the others either in labor productivity or in cost. It should be noted that the use of cutting-and-drilling machines in driving raise workings with a cross-section of 1.5 m², although it provides better working conditions for the workers, does not reduce the labor input of driving or the cost of 1 linear m of working. When workings are driven through solid coal, there are no expenditures for borehole drilling, but the need arises to install ven-

... partial-ventilation fans and the layout of ventilation pipes, as well as the driving of additional breakthroughs (about 0.25 m of breakthrough for each linear meter of raise working).

By time-and-motion observations, the summary data of which are given in Table 3, the actual labor intensity of individual processes in driving 1 linear m of a raise working was established.

Table 3

* When working at a height of 20–25 m
** When working at a height of 15 m

working (not including drilling work). The most labor-intensive process is breaking coal by the drilling-and-blasting method or with a jackhammer and the subsequent manual (pick) dressing of the working to a square cross-section. Depending on the hardness of the coal, these operations require from 40 to 55% of all labor expenditures.

The labor intensity of erecting the timbering is also high and amounts to 30–50% of all expenditures. In the process of erecting the timbering, the share of labor expenditures is distributed as follows. For carrying timber to the mouth of the working and delivering it to the face

60–70% is spent, while laying the cribwork with undercutting accounts for 30–40%. Thus, the high labor intensity of supporting raise workings is due, above all, to the difficulty of delivering timber to the face, which in most cases is done by lowering it on a rope manually or by dropping it down the borehole along which the working is being driven. Lowering individual posts on a rope is unproductive, and dropping them is unsafe for the driverman. In addition, when a post falls freely it often becomes wedged in the borehole. Raising timber to the face by means of light winches driven by a hand electric drill is also of low productivity, while the use of more powerful winches for this purpose is impeded by the difficulty of moving them in the working as the face advances.

When a working is driven through solid coal, timber is delivered by being dropped downward onto the platform of the adjacent stope, from where the timber is carried through a crosscut into the face of the working being driven. Therefore, workings through solid coal in the course of driving are, as a rule, connected along their entire length by crosscuts every 8 m. Driving these crosscuts additionally increases the labor intensity and cost of driving raise workings.

Investigations show that even with a well-organized work process, the rates of driving raise workings with support, using the existing methods, cannot exceed 3–4 m per shift, while the labor productivity of the workers is 1.5–2.0 m per output (not counting drilling operations).

It follows from the foregoing that in the mines of the Prokopyevsk–Kiselevsk district the entire complex of operations involved in driving raise workings, in most cases, consists of three basic technological processes: drilling boreholes 300–850 mm in diameter, enlarging the borehole to a square cross-section of 1.5 × 1.5 m, and preparing the working for support and erecting the support. In driving 1 linear m of working, the average labor expenditures (not counting downtime) are distributed as follows: drilling (with a diameter of 300–400 mm)—2.0 man-hours, or 30%; enlargement—2.4 man-hours, or 40%; support—2.0 man-hours, or 30% of the total volume.

Consequently, for the successful solution of the problem of comprehensive mechanization of raise driving, it is necessary to improve all the indicated technological processes. This must proceed both in the direction of creating special drivage enlarging machines and special types of support (making it possible to mechanize its delivery to the face and installation in the working), and along the line of improving the existing borehole-drilling equipment.

Tests carried out in 1956–57 by the Tomsk Polytechnic Institute of light crosscut-drilling machines LBS-2 at increased drilling regimes revealed the possibility of increasing the mechanical drilling rate by a factor of 2 (to 21 cm/min) without

increase in motor power. A simple modernization of the existing fleet of LBS-2 rigs (replacement of the feed nut and spindle) increases the labor productivity of drillers by approximately 1.5 times. On the basis of the results of testing LBS-2 rigs at increased drilling modes, it can be stated with sufficient grounds that the powerful SBM-3u raise-boring machines will also be able to drill at a feed rate twice as high (up to 38 cm/min).

Along with increasing the drilling rate of pilot holes, it is necessary to seek ways of using raise-boring machines to obtain a finished working. The foreman of the drilling shop at the Koksovaya 1 mine, M. V. Vasiliev, improved the LBS-2 rig, as a result of which it became possible to use it not only for drilling holes in the forward direction, but also for reaming them (on the return stroke) to a diameter of 500 mm. In 1956 the Tomsk Electromechanical Plant manufactured five such rigs under the designation LBS-2m; they successfully passed tests and are now in operation.

Kuzbass innovators have proposed, and are introducing into production, several types of drilling tools for LBS-2 rigs for reaming holes in the forward direction to a diameter of 650–800 mm, as well as reverse-stroke reamers 1100 mm in diameter for SBM-3u machines. Further increase in the borehole diameter is limited by the high energy consumption of existing reamer designs. In this connection, the Tomsk Polytechnic Institute carried out a number of studies, as a result of which an original-design RUP-1 reamer was developed, making it possible, with the aid of the SBM-3u, to enlarge holes to a diameter of 1500 mm.

At the end of 1957 the Anzhero plant “Svet Shakhtera” manufactured two experimental specimens of such a reamer. The forthcoming industrial tests of these reamers will show what technical and economic effect can be obtained by following this path of mechanizing the enlargement of workings to full section.

However, the use of the powerful SBM-3u raise-boring machine for enlarging holes to the dimensions of a finished working is limited by the field of application of the machine itself, which provides drilling of holes only from the main drifts. Usually, with a stage height of 80–100 m and irregular occurrence of the seams, in order to increase the accuracy of drilling the holes, the stage is divided into two substages by an intermediate drift. Owing to the great labor intensity of delivery through raises and the difficulty of installing the SBM-3u machine on the intermediate drift, it is not used for drilling holes in the upper substage. Therefore this method of mechanizing the enlargement of raises can be applied to approximately half of the total number of workings being driven.

Driving intermediate drifts is a forced and highly undesirable measure: when crossing an intermediate drift, the shield loses stability and often enters an emergency condition. Further operation of such a shield becomes difficult and entails a reduction in output, and sometimes a suspension of stoping operations. The need to drive intermediate drifts can be eliminated by solving the problem of directional drilling of boreholes relative to the lateral rocks of the seam.

Drilling boreholes along a prescribed trajectory over the full height of the level from a single setting of the machine would create the prerequisites for the development of a more advanced technique for enlarging and supporting workings, and would also reduce the labor intensity of the borehole-drilling process itself.

The specific conditions of driving raise workings do not make it possible to mechanize their driving with the aid of the heading machines known to us [4]. For this purpose it is necessary to create special heading machines. In developing the basic designs of such machines, various technological variants should be considered, which may occur in driving furnaces. From the operational point of view, furnaces may be driven with a square, circular, or other more complex cross section. Technologically, furnaces may be driven in solid ground or along a previously drilled borehole, in an ascending (from bottom to top) or descending (from top to bottom) order.

Workings of circular cross section, other conditions being equal, are more stable than workings of square cross section, have the smallest wall surface, and therefore require a smaller amount of support material. In addition, the increased stability of round workings will make it possible in a greater number of cases to use them without support, or to support the working after it has been driven along its entire length. However, round workings require the creation and adoption of special types of support, whereas workings of square cross section can be supported with the well-mastered crown timber support.

Driving workings in solid ground eliminates such a labor-intensive operation as drilling boreholes and does away with the large fleet of percussion-drilling machines. However, the creation of machines suitable for driving raise workings in solid ground is associated with great difficulties: in descending driving it is very difficult to transport coal from the face, and in watered seams also to remove water; in ascending driving there arises the difficult problem of ensuring the reliability of the machine’s movement during its operation. Existing heading combines drive horizontal and inclined workings in solid coal, moving by means of crawler travel or jacks braced against the walls of the working. Under condi-

in the workings of the Prokopyevsk–Kiselevsk district, whose coal seams are mainly of medium strength and stability and contain crumpled bands, combines with hydraulic props for wedging have not found practical application. Systematic falls of coal due to the thrust shoes deprive the combine of the possibility of movement (experience with the ShBM-1u combine at the mines named after Vakhrushev, Maganak, Baidaevskaya, and with the PKS-1 and PKS-2 combines at mines No. 13 and Koksovaya 1 [5]). Therefore the use of such feed mechanisms in machines for raise workings in the district’s mines is excluded. Movement of the machine can be ensured by props bearing against the support; however, the application of such a machine will be limited, since at present half of the raise workings are not supported. Moreover, a machine with an intermittent-stepping feed mechanism, other conditions being equal, is less productive than machines having continuous feed.

Combines with crawler travel do not have the indicated shortcomings; however, their movement along raise workings is ensured only with a relatively great crawler length, which causes an increase in the overall dimensions of the machine. Thus, for the PPG-3 pneumatic driving machine, intended for driving raise boreholes, the ratio of its length to the diameter of the borehole driven by it is 3.15. In the case of driving a borehole with a diameter, say, of 1500 mm, the length of such a driving machine would increase to 4.7 m. Installing and collaring such a machine even in a double-track drift is a very complex matter. Tests of the PPG-3 driving machine in Kuzbass mines also showed that, under conditions of weakly stable coals and crumpled bands, the crawler travel of the machine does not create the necessary thrust force for effective operation of the cutting organ¹.

It seems to us inadvisable to create a machine for driving raise workings through solid coal also because of the difficulty of carrying the working in the specified direction and the impossibility of ventilating the face by means of general mine depression. These questions can be solved much more simply when driving raise workings along boreholes. A predrilled borehole will permit the use of a machine with reliable rope feed, will, within certain limits, ensure the directionality of driving the working, and will create favorable conditions for transporting coal from the face during downward driving of the working.

When deciding on the direction for driving raise workings along a borehole—from top to bottom or from bottom to top—the following factors must be taken into account. In downward driving it appears possible to combine the operations of driv—

...in the driving and support of the working, to use the weight of the machine to create the feed force, and to irrigate the face more easily. However, this gives rise to the need for forced transfer of coal from the face of the working into the borehole and for measures to prevent the support from sliding under the action of its own weight. In upward driving, the need for forced transfer of coal into the borehole is eliminated, and the erection of the support is simplified.

To avoid unnecessary unproductive work, the most expedient arrangement, in our opinion, is a sequential circular scheme for driving the workings. Under this scheme, if one working is driven from top to bottom, then the adjacent working should be driven from bottom to top, and so on. This makes it possible to eliminate the idle relocation of the machine and the associated partial dismantling of it (in the case of moving the machine along the supported working). Preliminary drilling of the boreholes can be carried out with the existing crosscut-drilling machines. To facilitate the passage of the heading machine through the intermediate drift, it is necessary at the latter to ensure that the ends of the boreholes coincide. In practice, such coincidence can be achieved by installing the crosscut-drilling machine (located in the intermediate drift) over a borehole previously drilled from the main drift to the intermediate one.

In creating a heading machine, it must be borne in mind that the average monthly labor productivity of the workers engaged in its servicing, transportation, and repair should be no less than 4.5 running meters of working ready for support, if this machine does not change the labor input required for erecting the support. If, however, with the use of the machine the technology of support erection is also improved, then the average monthly productivity of the workers carrying out the entire complex of work for servicing the machine and erecting the support should be no less than 2.0 running meters of finished supported working per output. If these minimum requirements are not met, the machine will prove unprofitable.

It is also important to pay attention to the weight and overall dimensions of the heading machines being designed for raise workings. The investigations carried out have shown that the labor costs for drilling 1 running meter of borehole with the powerful and heavy SBM-3u machine and with the light LBS-2 machine under identical mining conditions are approximately the same, although at the same time it is known that the LBS-2 has a machine drilling rate almost 2 times lower than that of the SBM-3u. From this it is clear what great importance is attached to the maximum reduction of the weight and dimensions of machines subject to frequent relocation. In such cases one should not be carried away by an excessively high technical productivity of the machine if this entails a significant increase in its weight and dimensions.

KuzNIUI has developed a design for a universal heading machine for enlarging boreholes 400–500 mm in diameter to ...

diameter of 1300 mm, and also for a square cross-section of \(1.5 \times 1.5\) m. The machine is designed for driving workings according to a sequential-circular scheme. The machine is fed by the rope of a winch located in the ventilation drift. The support material is delivered in a special skip. The calculated labor productivity of the workers carrying out the entire complex of work for driving and supporting the workings and for transporting the machine is 3.5–5 linear m of working per shift; the advance of the face per shift is 8–12 linear m. The Tomsk Polytechnic Institute has proposed a basic layout for a heading machine with an operating member of the Gumenik combine type for enlarging boreholes up to a diameter of 1500 mm. The machine is rope-fed.

As already indicated, when driving workings of circular cross-section, along with the creation of a heading machine it is also necessary to create a new type of support, since the natural properties of timber do not make it possible to secure such a working. Circular support can be made from such materials as concrete, reinforced concrete, and steel, which, in comparison with timber, allow a greater variety of structural forms of support and of fundamental schemes for its erection. KuzNIUI and the Tomsk Polytechnic Institute have developed several variants of circular metal support. Some of them are undergoing tests; others are planned for manufacture.

The solution of the problem of comprehensive mechanization of the driving of raise workings in Kuzbass is a difficult but urgent task. Its solution requires broad research and design-engineering work with the participation of a large team of research workers, designers, and production workers.

LITERATURE

1. A. N. Volkov and I. A. Ushakov. Experience in the operation of the PKG-2 heading combine in the mines of Kuzbass. Kemerovo, 1956.

2. M. E. Feldman, B. S. Reizin. 1304 m of drift in a month. Mine Construction, No. 10, 1957.

3. V. Kochetov, A. Potapov, A. Sedov. On the work of the heading brigade of Mine No. 66 in the Moscow Coal Basin. Coal, No. 5, 1957.

4. A. S. Arkhangel’skii. Heading combines. Ugletekhizdat, 1956.

5. A. N. Volkov and I. A. Ushakov. Mechanization of work in driving development workings. Kemerovo, 1956.

Noted Misprints

Order 39

1. Report of KuzNIIUGI: “Mine tests of the PPG-3 pneumatic driving machine,” 1955. Archive collection of KuzNIIUGI. ↩