SELECTION, DESIGN, AND OPERATION OF MACHINES AND MECHANISMS FOR ERECTING PREFABRICATED REINFORCED-CONCRETE SUPPORT IN KUZBASS

V. G. Lukyanov, S. I. Semenkov, L. K. Dronov

(Presented by the scientific seminar of the Department of Labor Protection and Mining)

In the main guidelines of the five-year plan for 1966–1970, it was envisaged that production of prefabricated reinforced-concrete mine support in the RSFSR would be brought to 300 thousand m³ by 1970, as against 33.5 thousand m³ actually produced in 1965. In Kuzbass it is necessary to build new specialized enterprises for the production of reinforced-concrete mine support with a capacity of 140 thousand m³. Therefore, at present the determining requirement imposed on support for capital mine workings is the mechanization of the process of installing support in workings. Labor expenditures for supporting horizontal workings amount to 25% of the total labor input for driving them. Support installation is the least mechanized process among all operations of the drivage cycle. In order to eliminate heavy physical labor as quickly as possible, the efforts of design and engineering thought must now be concentrated, first of all, on finding effective means of mechanizing the support-installation process, since the bulk of heavy physical labor is concentrated in this process. One solution to this problem is the use of support-setting machines.

Having analyzed the design materials for existing and proposed support-setting machines and devices for erecting support in horizontal workings, as well as personal observations, production experience, and the results of analytical studies, we consider it possible to recommend the following:

1. In order to create serviceable support-setting machines, it is necessary to standardize prefabricated reinforced-concrete support, reducing the number of component elements in the frame, since the existing types of support are characterized by a great variety of structural designs. This creates certain difficulties in designing support-setting machines for the comprehensive mechanization of support installation. Standardization of prefabricated reinforced-concrete support will promote its wider introduction and will facilitate the solution of problems related to creating the necessary support-setting machines.

2. For each type of support and form of working (trapezoidal, polygonal, arched, and circular), we have recommended the corresponding types of support-setting machines.

3. The creation of new and the improvement of existing support-setting machines must proceed in inseparable connection with the design of reinforced-concrete support. Designers engaged in creating prefabricated reinforced-concrete support must take into account, as one of the basic conditions,

technology of its erection. Reinforced-concrete support for horizontal mine workings must have broader interchangeability of individual elements within a frame. This will make it possible to reduce the number of design solutions adopted when creating support-setting machines.

1. Research and experience from industrial tests of support-setting machines of various designs have enabled us to give them a certain qualitative assessment and to develop a number of general technical requirements imposed on them in design: a) provision of integrated mechanization of roadway support—lifting the support element to the place of installation; setting the support element in the design position; preparing the ground of the working for foundation slabs or support posts; packing the secured space; auxiliary operations—bolting, caulking, etc.; b) simplicity of design, ensuring the repair and manufacture of individual units in the mechanical workshops of mines and pits; c) support-setting machines must not interfere with other processes of the heading cycle; d) support-setting machines must be sufficiently universal and highly productive, and must have good maneuverability, allowing the support-setting machine to be moved quickly away from the face during blasting operations; e) in order to move the support-setting machine, the construction of special tracks should be excluded and transport routes should not be occupied; f) the possibility for the support-setting machine to work while storing support elements along the axis of the working, as well as from special platforms and cars; g) the support-setting machine must have a low weight and sufficient strength and must ensure unobstructed passage to the face for compressed-air, ventilation, and other pipes; h) it must ensure safe work, be self-propelled, provide a sharp increase in the labor productivity of timbermen, and be serviced by no more than two workers.

In addition, the support-setting machine must be designed for supporting workings of quite definite cross sections and shapes; a change (beyond certain limits) in the shape and size of the cross section of a working supported by a support-setting machine of a given type is associated with a considerable complication of its design. Each support-setting machine, in order to perform its basic functions—lifting the support element to the place of installation and setting the support element in the design position—must have at least two mechanisms: an actuator, a feed mechanism for the actuator, and a mechanism for moving the support-setting machine along the working. The most fundamental and decisive element in the design of a support-setting machine is its actuator, which performs the first and most important function of the support-setting machine—the installation of the support element.

1. The designs of mechanisms known at the present time for erecting permanent support in horizontal mine workings have been divided by us into two main groups. The first group of mechanisms includes support-setting machines intended for mechanizing the erection of all elements of the support frame or arch. The second group is intended for performing individual operations—installing the crown member. In turn, the existing support-setting machines, depending on the method of their installation, are divided into the following groups: Group I—support-setting machines on carts (22 machines); Group II—suspended support-setting machines (4 machines); Group III—support-setting machines of the mounted type (4 machines); Group IV—climbing-type support-setting machines (3 machines); Group V—block-setting machines (6 machines); Group VI—means of small-scale mechanization (13 machines).

The above division of support-setting machines into groups does not claim to be an exhaustive classification of such mechanisms.

1. In the classification of support-setting machines proposed by the author, the full diversity of types of existing and designed support-setting-machine structures is taken into account sufficiently completely, with allowance for quite definite cross sections, shapes of workings and support structures, as well as the general requirements imposed on support-setting machines. This classification facilitates the study and design of support-setting machines for mines and ore mines and enables production workers to select the corresponding type of support-setting machine most suitable for particular specific conditions. It will make it possible to carry out the development of new support-setting machines in a considerably more substantiated and purposeful manner.

2. We have developed a support-setting machine* for erecting prefabricated reinforced-concrete support in two-track workings of arched cross section. In order to increase mechanization of the process of transporting and installing the tubing, its gripping device has three degrees of freedom, which makes it possible to set the tubing in the installation position while the support-setting machine is moving along any rail track. The third degree of freedom of the gripping device makes it possible to set the tubing in any specified position without manual adjustment. A prototype was manufactured in a mine workshop and underwent industrial tests at the Chertinskaya-Zapadnaya mine. Subsequently, the ore-repair plant of the Kuzbassshakhtostroi combine manufactured the first batch of these support-setting machines. With the aid of such an improved support-setting machine, at the Krasnogorskaya mine 300 linear meters of a field drift with a clear cross section of 12.6 m² were supported with KuzNIIshakhtostroi tubing at an average rate of 1 m per shift. The support-setting machine is mounted on a self-propelled special platform, and can also be mounted on a PPM-4 loading machine. This variant of the support-setting machine is promising, since support will be installed immediately after the advance of the face, i.e., without temporary support. When the reach of the working boom is changed, it can also be used for supporting single- and double-track workings with URP slabs and frame-type reinforced-concrete support.

3. The creation of a large number of support-setting machines and the wide introduction of prefabricated reinforced-concrete support raise the question of the need to develop a method for calculating the productivity of a support-setting machine. A method has been developed and a calculation formula has been derived for calculating the productivity of a support-setting machine.

4. Of the existing support-setting machines in Kuzbass, the following support-setting machines most closely meet the requirements: a) UT-1 and UT-1M tubing installers designed by TsNIIpodzemshakhtostroi for supporting main double-track workings of arched outline with lightweight TKG-0.75 reinforced-concrete tubing designed by KuzNIIshakhtostroi. We believe that, in order to ensure higher productivity of the installer, it is advisable to increase the geometric dimensions of the tubing (increase the width to 1.0 m); b) a crawler-mounted tubing installer based on the UP-3 machine for supporting, with lightweight TKG-0.75 reinforced-concrete tubing designed by KuzNIIshakhtostroi, workings driven at a gradient of 0.05 during the construction of hydraulic mines; c) a support-setting machine of our design for supporting single- and double-track workings with lightweight reinforced-concrete tubing 0.5 and 0.75 m wide. Of all the support-setting machines used in the mines of Kuzbass, the UT-1M tubing installer designed by TsNIIpodzemshakhtostroi has nevertheless become the most widespread. At present it is used—

* Dronov L. K., Bizenkov V. N., Lukyanov V. G. Support-setting machine for erecting prefabricated reinforced-concrete support in mine workings. Application No. 758075/22.

...at the Chertinskaya-Zapadnaya mine of the Belovugol trust, and at the Vakhrushev mine of the Kiselevskugol trust. It was used only on crawler tracks during construction of the Grammoteinskaya No. 3–4 hydraulic mines of the Leninskshakhtostroi trust and the Baidaevskaya-Severnaya mine of the Kuznetsskakhtostroi trust.

Until February 1964, driving of field drifts and crosscuts was carried out using temporary support. A section 60–75 m from the face was supported by temporary support made of special-profile arches No. 18. The ribs and roof were tied together with wooden lagging: the roof continuously, the ribs at intervals.

In February 1964 a new technology for driving and supporting field drifts with tubbing support installed right at the face was developed and introduced into production at the Chertinskaya-Zapadnaya mine. Reinforced-concrete support is now installed immediately after the advance of the face; consequently, the need to use temporary support has disappeared, which in turn reduces the labor intensity of the work and lowers the cost of driving the opening. The proposal was developed and introduced into production by S. I. Semenkov (chief engineer of Belovo Mine-Construction Administration No. 2), V. G. Lukyanov (associate professor of the Tomsk Polytechnic Institute), together with employees of the mining section of Belovo Mine-Construction Administration No. 2: L. V. Shigaev (head of the mining section), I. V. Mukii (foreman of the driving crew), and Yu. P. Ivchenko (crew leader of the driving crew).

Working according to the new technology, Comrade Mukii’s crew achieved average monthly advance rates of 85–102 linear m. The transition to the new technology made it possible to release 10–12 drivage workers from the face without reducing the rates of field-drift driving. When working according to the new technology, the use of temporary metal support and lagging at the face was completely eliminated. The saving in materials per 1 linear m of field-drift driving amounts to 10 rubles 23 kopecks. Compared with work under the old technology, the productivity of the drivage workers increased by 35%. Labor input per 1 linear m under the old technology was 13.3 man-days, and under the new technology 9.9 man-days.

During the driving of field drifts by the new technology—supporting with tubbings right at the face, without temporary support—no cases of tubbing support being disturbed by blasting operations were observed.

When drawing up the drilling-and-blasting passport, a number of variants were tested and the most effective passport was selected in terms of the coefficient of utilization of blast holes and the throw of rock after blasting. Thus, in January 1965, in the eastern field drift, a KISH of 0.92 was achieved, and in April 1965, a KISH of 0.94. The throw distance of rock was 10 m. Safety of work increased sharply under the new technology, since all work is performed under permanent support. Excessive breakage of rock during drilling-and-blasting operations was almost completely eliminated, especially when replacing temporary support with permanent support. Under the mining-and-geological conditions of the Chertinskaya-Zapadnaya mine, with steeply dipping strata, during resupporting significant rock falls usually form, the clearing of which consumed much time. The production standards and quality of the completed work improved significantly. With the introduction of the new technology, fulfillment of output standards increased considerably. Thus, in 1963 and 1964, when field drifts were driven by the old technology, fulfillment of output standards was 102%, and wages were 9 rubles 60 kopecks per shift; in 1964 and 1965, under the new technology, output standards were fulfilled by 122%, and wages were 10 rubles 85 kopecks per shift.

The introduction of the new technology made it possible to save 41 rubles 50 kopecks per 1 linear m of opening driven. As a result of the introduction of the new support technology...

with tubbings in 1964 alone, Belovo Mine-Construction Administration No. 2 saved 61 thousand rubles.

At present the team is working on the introduction of a smooth-walled tubbing support—GTK, designed by KuzNIIshakhtostroi, for support at the face.

Thus, the use of support erectors in erecting prefabricated reinforced-concrete support is a technically expedient and economically advantageous direction; it makes it possible not only to save living labor but also to make it easier, changes the nature of the work of drivage workers, improves working conditions, increases job safety and the culture of production, and also ensures the concentration and intensification of work in all links of the technological chain for setting the support element in its design position.