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Summary on the final work

Content

1. Introduction

1.1 Actuality of theme of work

Project–oriented management style enhances effectiveness of the controlled process by 30–40% or more [1–4]. Particularly actual management of projects in the coal industry, which characterized by specific features that increase project risks [5,6]. The main factors increasing the risks of coal mining project is the low reliability information on low–amplitude disturbance of the coal seam, unstable operation stope, low reliability of the equipment and downhole equipment, etc. In connection with this very urgent task is to develop measures to increase the information resources of coal mining project, which is achieved primarily all due to additional low–amplitude disturbance excavation intelligence post.

However, even with accurate information about the location and parameters low–amplitude disturbances, we can not determine in advance the degree of slowing rate podviganiya stope in the transition zones of low–amplitude disturbance. The reason for this is that small–amplitude disturbances are often substantially differ by type, amplitude, and the azimuth angle of incidence, even within the fault plane excavation column. In connection with this urgent task is to determine the Depending on the pace podviganiya stope on the intensity of low–amplitude disturbance.

1.2 The goal of master's work

Objective: To determine the rate based cleaning podviganiya slaughter on the intensity of low–amplitude disturbance

1.3 The object and subject of study

The object of this study is a long column of excavated stope.

The subject of research processes are violations of rock rocks and their influence on the rate of podviganiya stope.

1.4 The tasks of master's work

The main objectives of the study:

  1. The technique of forecasting maloampletudnogo violation.
  2. Detection rate of progress depending on the working face, depending on the performance of breach of the site take out the column
  3. Selection and justification of the rational development of technology take out the pole, depending on the disturbance

1.5 Idea of work

The idea of work – is to link the rate of decline podviganiya stope with intensity of fractures and replacements

2. Basic maintenance of work

In Fig. 1 shows a typical vertical sections of low–amplitude disturbances in w / y Pokrovskoye. As a typical violations found thrusts 1, discharges of 2, 3 shifts, erosion 4. The amplitude of the faults varies from 0 up to 5m or more. The histogram shows the amplitudes of the disturbances that it satisfactorily consistent with an exponential distribution (Fig. 2). This indicates that that the more common disorders with a small amplitude. In this connection there separate the problem of determining the equivalence of violations with respect to their transition stope.

For example one violation with an amplitude of 1.7 m can be equivalent to several violations that have amplitude of 0.2–0.5 m on the degree of slowing down podviganiya lava. The question naturally arises as to small amplitude disturbances have a negative effect on the functioning of the working face as violation of the amplitude, which is commensurate with the capacity of the reservoir are working on.

In addition, the angle plays an important role meeting low–amplitude disturbances with a line of lava.

Figure 1. Typical small–amplitude disturbances of the coal seam

Risinok 2. The distribution of the amplitude of disturbances

In Fig. 3 illustrates the final singularity. This illustration shows a fragment Plan of mine workings in the area mining excavation column. Testing of stock is to develop high–pillar system of mechanized complex. Planned growth podviganiya stope in the order of 100–120 m / month. With removable power paste is 1.7–1.9 m and a length of 250 m of lava monthly production varies in the range of 60–80 thousand tons of raw coal.

In Fig. 3 clearly shows the traces of maloamlpitudnyh violations that formed at the intersection of the horizontal fault plane irregularities. These traces of low–amplitude disturbance are given in separate locations segments, polylines, branching beams, etc.

Typically, even in the eyes noticeably slowing podviganiya working face on those areas where the density of the disturbance more. So on a site that was free from violations of lava took place over the last month more than 120m. In the section 2. where there was one violation in the lower vyderzhanone of lava and one local–level ventilation drift actual podviganie lava is smaller and does not exceed 80 m / month.

In sections 3 and 4 of the lava entered the zone of intense disturbance, which is expressed in the form of a bundle of branching traces shifter. At the same time in the last sections podviganie lava was only 15–20 m / month.

Thus the apparent marked inhibitory effect maloamlpitudnyh violations.

The effect of the angle between the line of the violation and line stope still difficult to say anything. However, in terms of geomechanical view, it is clear that the magnitude of this angle should have a significant effect on the rate of lava through the resistance podviganiya immediate stope roof.

Fairly well known that the parallel orientation of fault plane violations and line stope most negative impact on stability of the immediate krolvi. In this case the collapse of the roof, and local dumped in the local labor prosranstvo stope most likely.

Meeting breach at a right angle of the least painful for the lava because the stability of the roof is lowered to a minimum extent. Vlyaiet also on the stability of the roof in the slaughter of the angle of incidence abatement fault plane violation. The nature of this effect is ambiguous and requires special geomechanical studies. Fault plane at angles of incidence close to Horizontal is more likely rushenie immediate kroeliv as of delamination. When the fault plane is vertical, is more likely inrush roof in the form of mutual sliding of rock blocks relative to each other.

Both are significantly delay the collapse of the roof podviganie lava create hazardous conditions underground, promote intensive wear downhole equipment and technology.

Figure 3. Effect of intensity of disturbance formation the rate of stope podviganiya

Separately, it should be said about the erosion of the coal seam and its replacement gangue. For this type of violation is closely related the presence of layers of rock within the reservoir. In such cases, the operating manager faced with the destruction of waste rock that the executive faceting shearer can not always do. If you breed substitution represented by thick siltstone and sandstone, the more stable, whereas it has to blow up, which greatly complicates the transition zones low–amplitude disturbance.

Thus it is obvious that the dependence of the rate of abatement podviganiya slaughter on the intensity of low–amplitude disturbance is sufficiently complex and at the first stage it is advisable to test the empirical relationship, whose parameters are calibrated based on the analysis of evidence.

With that said, suggested the following empirical formula:

where N–number of unit–amplitude disturbances within a month area S podviganiya stope; k – conversion factor disorders; h – the amplitude of the violation; m–Removable seam thickness; – an acute angle of the meeting violations of the line working face in a horizontal plane.

This formula is built taking into account the physical meaning of the geomechanical processes occurring during the interaction with the working face small–amplitude violation. So the longer the violation, the stronger its influence on the rate of podviganiya stope. The increase in the amplitude of disturbances and a decrease in the angle increases the likelihood of meeting the immediate roof collapses and slows podviganiya rate of lava. The terms of the formula inside the brackets approximately equal in size and vary from 0 to 1 or slightly more. In other words, these terms are comparable, which gives reason to put their effects.

This approach allows us to consider separately the negative effect of the amplitude violations and the angle between the line of lava. Therefore, even if perpendicular orientation to the violation of the lava when the cosine of the angle is zero, negative effect is due to his violation of finite amplitude.

The transition rate indicates the direction of the transition disorders stope. If culling is transferred from the hanging wing breach to horizontal, the negative effect of violations compared with the case When the lava moves from lying in the wings hanging, that is selected to hanging below the wing and in the immediate roof in a certain section podviganiya lava enters the coal seam weak, prone to collapse into the workspace stope .

In Fig. 4 shows a graph of the experimental points obtained

Figure 4. The dependence of the rate of mining stocks shown on the specific low–amplitude disturbance


According to field measurements. It is evident that between the specific measure disturbance as defined by the formula (1) and the area, in the spent Within a month there are statistically significant inverse relationship: the more reduced disturbance of the reservoir, the lower the rate of lava and the podviganiya smaller area of the excavation, it works off the post. The coefficient of tightness connection is equal to 0,62–0,71, a testament to its relatively high level.

The linear dependence of the rate of return podviganiya lava on the specific reduced disturbance better than the exponential, since the linear relationship reflects the physical meaning of the geomechanical and technological long process of coal mining stope. Since the exponent never crosses the line of abscissas, but will be infinitely close to it, which contradicts the physical meaning of the process. Practice shows that the disturbance at the critical layer is already working face can not move and stops, reflecting a linear inverse relationship.

The line crosses the x–axis in the coordinate 0.209. This is precisely the magnitude of the disturbance meets its critical level, where the lava loses the ability to move on. Installed pattern and its numerical characteristics are theoretical the basis for improving the management of coal mining project. With the help function can be found to assess the expected rate podviganiya longwall faces in areas of low–amplitude disturbance and proactively take action to stop the project risks parry lavas.

Further study will clarify the value conversion coefficient disorders, as well as the influence of the angles of incidence shifter low–amplitude disturbances.

3. Сonclusions

This paper describes the setting and start solving the problem of developing such a system, that could give a reliable forecast of the pace in the face podviganiya ochisnogo zones of low–amplitude disturbances. If such a system to develop and it will be to give reliable data, while engineering–technology staff can predict the production of lava on the front and thus compensate for any defects or other ochisnym face advance to take special measures preparation for the transition ochisnym slaughter of these unfavorable zones. so neytrolizovat or drastically reduce the negative of such factors on posletstviya stability ochisnogo face.

References

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