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Institute of Mining and GeologySpecialty: Mining of mineral resourcesTheme of master's work: «Choice and justification of rational method of maintaining the stability of soil excavation generation with pillar system»The chief: Solovyov Genadiy Ivanovich |
1. Relevance. One of the main tasks of further development of underground coal mining remains the creation of effective means and ways to counter increasing with the depth of the harmful manifestations of rock pressure in underground coal mines in order to maintain their stability.
Experience in coal complex geological conditions of deep mines of Donbass shows that the total volume of work involved in repair and excavation perekrepleniyu roadway is currently about 80% of total labor costs for conducting excavations. At the Ukrainian Donbass mines annually repaired and perekreplyaetsya over 25% of the total supported roadways, which is more than 2000 km per year. This the level of mechanization of repair work not exceed 3 - 5%.
Mining Science and practices are constantly being improved and applied new ones are created ways and means to minimize the harmful manifestations of rock pressure in excavation workings. However, the development of new technology decisions on the conservation of stability extraction workings are not always adequately take into account the specific features of their operation, For example, the maintenance of transport and air extraction workings behind the lava in a parallel flow ventilation intensively the debugging excavation of fields. Mechanical processes in the array are considered, mainly, without a detailed accounting irregularity manifestations rock pressure along the length of the development and deformation features individual layers of the roof, the soil and the sides develop as a result Opportunities for improved means of strengthening the lining of the workings not fully utilized. Not this aspect of the problem maintaining the stability of extraction workings in especially difficult circumstances exploitation is one of the main reasons for the lack of scientific feasibility of new designs lining gain to compensate for the negative effects of uneven loading of neighboring sets lining, as well as the lack of evidence-based recommendations on the choice the parameters of proposed technological solutions.
Thus development of new technological solutions for sustainable conservation the soil and prevent penetration of legs sets lining in the weak rock soil is very relevant, especially when used in cleanout bottom high-performance mechanized complexes.
2. Objective was to develop new ways to prevent soil heaving rocks, excluding the pricking soil foot supports and the determination of its rational parameters.
3. Scientific novelty. As one of the options to solve this problem proposed use of the new design lining gain, which represents the slope yielding "scaffold" of rectilinear spetsprofilya, hingedly connecting to a segment spetsprofilya, fastened in the middle part of each leg is fixed with two locks (Clamps, straps and nuts). Application of the lining of the amplifying allows you to redistribute the load, the perceived set of powered support for 4 legs - 2 legs and 2 extra roof support pillars, which at need to be equipped with additional longitudinal stabilizers in the form of cross bars welded to avoid pierce the soil drawing 1.
drawing 1 – Scheme Installation inclined pliable lining to prevent amplification swelling, pierce the soil and intensive lateral displacement of the contour.
In addition to the redistribution vertical load on the ground this magnifies lining because of its oblique arrangement creates a resistance to lateral displacements of the leg supports in cavity under the action of increased production of lateral loads on the lining excavation generation.
At the present technical solutions has filed for a patent for an invention.
4. Practical value. The use of known methods is limited to a considerable complexity implementation cluttered extraction workings, significant material expenditures.
Thus use of a new design reinforces lining, working with using the principle of active resistance squeezing rocks soil, prevent piercing legs lining of the soil, and the establishment Lateral displacements of legs counter lining of the cavity output, would greatly enhance the effectiveness of of technological solutions in the intensely deformed preparatory workings of deep mines in the zone of influence of sewage work.
5. Research Methods. In this paper, the following research methods: an overview literature and patent searches on the topic; Engineering analysis of the effectiveness of existing methods and means retention and protection of development workings in deep mines; instrumental and visual observations of rock pressure in various zones to maintain development workings at using the methods of mounting and shaft of the workings and proposed new lining gain; laboratory studies on Structural models and on models of equivalent materials; Analytical studies with the use of force techniques, finite difference and finite element.
Instrumental Observing the manifestations of rock pressure are normally held on typical plot of preparatory workings, which, as motion and moving toward the stope in turn supported outside the zone of influence of slaughter, in the zone of bearing pressure, in the alignment of lava and it in the zone of influence of developed space, subject to means mounting production and erection of supporting structures on adjoint with the stope workings under technological passports conducting clearing operations and mount preparations workings
Measurement relative displacements of roof and floor, as well as laterally preparatory excavations is usually carried out by metering roulette, (instructions VNIMI), metal telescopic racks or special devices for remote measurements. The measurements are made along the contour, and depth gauging stations installed on the control and experimental plots with a periodicity of measurements: outside the zone of influence treatment works - once a week, and in the impact zone of lava - one time in 1 - 2 days.
To determine relative displacements of the roof rocks, soil and laterally in the overall workings Convergence is the current measurement of their displacement from the central (Horizontal and vertical) lines, generated by hanging long gum between hooks opposite frames.
To determine absolute displacements of wall rocks at intervals 1 - 2 times per quarter is laying leveling course of preparatory making the experimental sites.
To clarify physical and mechanical characteristics of the wall rocks is necessary when drilling wells for deep metering stations to choose rock samples using the core sampler withdrawal. Determining the strength and deformation properties of selected rock samples will be produced in laboratories Mining Institute DonNTU.
Given the specificity and objective research on this work, which is development and implementation in terms of mines. ET Abakumov and them. MI Kalinina new ways to preserve the stability of intense deformable extraction workings by optimizing the interaction the elements of structural-hybrid system "wall rocks - support - Support structures lining gain.
Measurements of lateral displacement rock at the contour extraction workings are carried out on 3 groups contour metering stations (in the center of each plot and observations on the 10 meters from him on both sides along the length of production). Contour gauging station is being built on three adjacent frames, supports and at each of them are installed coaxially to 2 contoured frame: in the top-soil and sides of the generation (above and below the coal seam). Contoured frame represents a segment of a wooden rod cylindrical diameter of 35-40 mm in length at the top - 0,8 m in the soil - and the sides production - by 0,6 m (drawing 2).
drawing 2 The unit of contour metering stations for the instrumental observations of rock pressure at the contour of excavation generation.
To implement measurement of the speaker to the formulation of the end of each frame inserted metal hook to engage the tape measure. All boreholes drilled with a diameter of 42 mm in depth, corresponding to the length of installed in their frames. Fixing the hole in the frame is made with using wooden wedges.
6. Testing. In Currently, new construction lining gain is Experimental-industrial testing at the mines it. E.T Abakumov and them. MI Kalinin GP "Donetskugol".