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Abstract

Introduction

To date, relevant issue is the problem of coal mining in the mines of Ukraine[7]. Coal mining is complicated by factors such as a large depth of development, a high level of rock pressure, lamination of the array, fracturing, water abundance, high gas-bearing formations. The most problematic factor when developing reservoir is low-amplitude disturbance. The difficulty is that to conduct clean-up violations with small amplitude is almost impossible to detect. The distances between the exploratory wells in the hundreds of meters therefore catch violation amplitude of 0.3–1.5 m is almost impossible. In this regard, use of a range of geophysical methods that produce immediate exploration of small-amplitude disturbances. However, they require a significant investment for the purchase of special equipment. The complexity of processing the intermediate data during the work is significant. Besides restore parameters violations and their origin is a task that does not have a unique solution. In addition, the reliability of the exploration is usually not more than 80 %.

1. Relevance of the topic

Despite significant advances in the development of the theoretical foundations of control more than half of the projects end as an afterthought, overrun budgets and cuts purposes. This negative result is due primarily to the current turbulent environment projects in which the parameters and structure projects are characterized by strong uncertainty.

What is more significant, the more necessary changes to the project plan and the faster they should be taken. However, the standard iterative and therefore lasting procedures for review, analysis and decision changes are in basic conflict with the operational management of the project.

Without rapid adaptation to a turbulent environment that is constantly changing, projects are doomed to failure. On the other hand, flexible electronics and motor control and agile, especially in the scrum mode suitable only for fairly narrow range of projects in the field of information technology, which refers to the development of software products. The point is that in general, the project resources have no such liquidity as an idea in the head programmer.

Thus there is an urgent need to justify the models and methods of surgical management of projects based on standards of project management based on the best achievements of modern and flexible management requirements for rapid adaptation to control unsteady turbulent environment. It is this environment is a constant source of uncertainty that can be reduced only through the accumulation and monitoring of timely, relevant information. This makes the relevance of information on operational project management in terms of parametric and structural uncertainty.

2. The purpose and objectives of the research, the expected results

Improve the quality of project management and exploration of small-amplitude conversion violations long stope.

3. Overview of Research and Development

3.1 Overview of international sources

Now the problem is solved forecast malomapplitudnoy disturbance with the aid of a number of geophysical methods [4, 5]

3.2 Overview of research on the topic in Ukraine

In Ukraine, the research prediction of small-amplitude disturbances occurring in the rock mass, is engaged in Research and Development Institute of the NAS UkrNIMI

3.3 Overview of research on the topic in the Donetsk National Technical University

Department of Surveying at the Donetsk National Technical University is one of the leading scientific organizations, one of the objects of research in the department is the prognosis of low-amplitude disturbance. This problem has been PhD prof. Nazimko V. V.

4. Object of study

TThe object of research is the process of operational intelligence SAV

5. Object of explorer

The subject of research is mathematical models and methods of operational intelligence SAV under time pressure on decision-making.

6. The idea of work

The idea of work is a unique compilation of the project management plan identifying violations, followed by small-amplitude off a bench under the adopted plan.

7. Numerical modeling techniques elastically deformed area around small–amplitude disturbances (SAV)

To compare the effectiveness of methods of transition maloaplitudnoho violations were tested following technologies:

1. Technology transfer of small-amplitude infringement without prior training and strengthening fragile roof in the zone of violations

2. Technology transfer with advanced hardening of the roof under the normative document

3. Technology transfer through a transition chamber, which is constructed in advance and independently of the treatment works.

Evaluating the effectiveness of technology transfer was carried out using computer simulations based on package FLAC3D. Use of this software package due to the advantages that it has over currently known software packages.

First runs in conscious dynamic mode. This means that all the calculations of stress and strain being based on Newton's second law, ie, the dynamics and the most difficult is the calculation of static equilibrium. To solve our problem dynamic mode is very important because it allows to take into account the speed of advance of lava, which, as already mentioned, significantly affect the stability of the species housed in a zone violation. At low speed advance of lava iterative calculation of each cycle is so long until a static equilibrium of the surrounding rocks. At high speeds advance of lava rocks contain all the time are in a nonequilibrium state, it is easy to consider a reduction in the number of iterations of the calculation cycle advance of longwall.

The second package has 12 models the strength of the rock mass and soil. Due to careful selection of model strength and its parameters can improve the reliability of the final results simulation.

The third program is designed so that you can save the results of previous decisions and the status of all model variables at the previous decision, and then continue to solve a new problem. With the objective of testing the technology transfer violations bench this advantage is paramount. The fact that compliance with the initial state of the system must first solve the problem of tunneling transition chamber and ensure its stability to approach the bench. Followed resolve separate task switching camera working face. It is desirable to solve the transition in advance of lava several cycles to realistically assess the dynamic changes enclosing rocks.

Fourth package has built a programming language that lets you write your own programs that use the modules package FLAC3D, which enables you to create powerful software, the possibilities are limited only by the capabilities of the programmer and technologist requests and geomechanics.

Fifth to solve this problem, three-dimensional model is chosen as areas of penetration testing and bench vzaimoperpendikulyarnyh, and by sinking all three major deformation of the rock mass around the face preparatory nonzero. This means that the condition of plane strain can not be identified.

big advantage of the package before the procedure of finite element method is that the nodes adjacent areas can not match. This greatly facilitates the construction of complex design schemes.

modeling of the stress-strain state of the rock mass is as follows. Originally built digital model is simulated. In this case, we create a model of rock strata, indignant small-amplitude excitation. In Fig. 8 shows a three-dimensional model that reflects a violation of the third group with an amplitude of 2 m seam thickness of 1.8 Parameters infringement taken as typical for the statistical analysis of data breaches within the field of mine Krasnoarmeyskaya-Zapadnaya № 1

Фрагмент плану гірничих виробок

Rice. 1 fragment Plan of mine workings М 1:5000

In the process of constructing digital models were set initial data, relevant mining and geological conditions of the block 2. Before choosing the final model parameters were held preliminary calculations, which evaluated the main manifestations of rock pressure (lowering the immediate roof fracture rocks around and around a moving violation lava rock pressure distribution pattern). First, the model was tested strength Coulomb-Mohr, who is the most appropriate for the description of rock. It was found that a number of important parameters changes thicker around the violation did not accurately modeled. By successive selection was tested three models of the strength of rocks and selected parameters of the model that adequately reflect the behavior of the array in real field conditions.

Finally it was decided to use a modified model of Coulomb-Mohr, which takes into account the impact of the weakening of rocks along the plane of the layers. In view of the deformation and strength parameters housed species listed in Table 1.

Second time consuming tasks associated with the estimated breakdown area into zones or elements which made the solution of the differential equation of dynamic equilibrium solid. It is necessary to perform a fundamental requirement is mandatory for all numerical methods for solving differential equations: the size of neighboring areas and their sides or faces to be compared. This means that the size of the faces of a tetrahedron, or other volume element of which is built the whole model should not vary greatly. In practice this means that the sides of the triangle such should not differ by more than three times. This means that there should not be too thin and elongated zones or elements. Likewise, should not be in close contact areas or elements whose dimensions are more than three times. For better convergence of the solution generally desirable that the difference in size does not exceed 1.5. To comply with the requirements specified package FLAC3D provides a set of primitives, which are easy to create with different volumes and spatial forms.

When modeling a layered medium, which is an array of sedimentary rocks, it is necessary to build a model so that it is convenient to introduce layer properties of host rocks, and on the other hand, creating a cavity chamber and goaf behind the longwall. As the camera is tilted to the bedding at an acute angle of 9°, to combine these two things very difficult. At the same time meeting the above requirements will inevitably arise narrow elongated zones that when solving a differential equation is the source loop solution.

Table 1. Deformation and strength characteristics of host rocks

name of the breed Sandstone siltstone antratsyt
Module volumetric compression GPa 10 9 7
Shear modulus, GPa 3,6 3,8 2,5
The angle of internal friction matrix, deg 35 20 38
Strength in the matrix, MPa 5 4 1
Matrix tensile strength, MPa 8 3 0,5
Dilatansii angle, deg 25 23 25
Strength in layers, MPa 2 1 1
Angle dilatansii along bedding, hail 25 25 25
The angle of internal friction along the bedding, deg 30 20 20
Strength in tension normal to the layers. MPa 1 0,5 0,1

Also developed a separate program to simulate the process of reducing adhesion and mobilization of domestic thorns on the rock. The standard package is no such procedures, and examples are not shown. However, no procedure weakening grip in the array after the rock simulation results are quite at variance with the observed manifestations of rock pressure. Only after the development of such a procedure has significantly closer to reality simulation results.

Графік переходу стану ймовірності

Figure 2. switch mounting camera animation: 4 frames, 10 cycles of repeating, 76 kilobytes

The estimation of the developed model provides the basis of its application for the analysis of the stress- strain state of rock mass violations during the transition of small-amplitude long working face. Testing of the reservoir was carried out in all cases zahodki cycles or to reflect the main features of shearing will active lava rocks around. Total applied 6 cycles of advance of advance of an average length of about 5 m. One cycle advance of transition implemented to the oven for four cycles bench moved through transition trench or chamber and one cycle was carried out in the hanging wing disturbed layer. The results of each cycle was kept in a separate file, which is located in the electron attachment and is ready for further analysis of any available information.

8. Planned result

  1. With the reduced method to develop a plan of study available SAV.     
    2.     
  2. In the case of SAV, adjust the plan to develop areas of the coal seam, or even to decide on new development plan     
    3.        
  3. Collect a special committee to oversee the implementation of the plan     
    4.     
  4. Gaining actual results, synthesis and analysis.     

9. Novelty

Novelty of scientific statements as a whole consists of a theoretical and methodological principles and tools of stochastic simulation designed as an open thermodynamic system that transmits itself through information flows.

Conclusion

Thus we can draw the following conclusions:

Small-amplitude disturbances without additional exploration of parameters leads to a delay of coal within 5-12 months, significant economic losses are determined by hundreds of million, and increases the risk of underground works. Today there is a wide range of methods and techniques of forecasting maps and their further exploration geophysical methods. Reliability methods and technologies varies from 60 to 85 %, and a broad range of value: from 10 thousand UAH. by a simple prediction to several million for a three-dimensional seismic survey.

Interest in the use of technology forecasting and intelligence practitioners in IAP due to a variety of factors, including the principal is a chronic shortage of objective information on losses and negative effects of transition MAP blind, it is likely not receive credit for working small-amplitude disturbances damaged inventories uncertainty of the geological environment and its nonstationary nature, psychological factors associated with fear of losing career and propensity to prefer saving on the cost of exploration today than getting uncertain loss in the future, the lack of reliability of geophysical exploration technologies and their high cost and inability to verify the authenticity of the forecast maps in the case of the decision to bypass it.

Fundamental solution to the problem of widespread use of technology forecasting and intelligence MAP during coal can only be achieved through the use of project-based approach. In this project the forecast and the MAP intelligence tied to the project working extraction pillar and project management is implemented efficiently in terms of parametric and structural uncertainty of geological and organizational environment.

Optimality criterion operational project prediction and exploration of MAP, which takes into account the profits of coal, the cost of coal price forecast and intelligence, loss of trained coal reserves and losses incurred by the mine during the transition MAP.

A project plan, which laid the basis for the following principles: integration of methods for prediction and exploration of the advantages of the method using all the information accurate maps for extrapolation to new areas that have not yet perfected, and methods that make it possible to construct spatial cards reliability prediction ; division of risk between the parties to the project, which brings together several neighboring mines work out the damaged layers of the same geological conditions, involving companies, the Ministry of Energy and insurers.

Found that the most negative branches of the project structure (decision tree) that may arise during its implementation is the decision about moving violation that unexpectedly changed to bypass. These branches most significantly reduce the quality of project management prediction and exploration of MAP and increase parametric and structural uncertainty.

Proved that the most important role to improve the quality of project management and exploration forecast maps are informational support. Its main components are an asset of the project as documented experience of transition MAP, the knowledge base in the form of rules for operational decision-making model to quantify the negative impact of small-amplitude disturbance on performance of the stope.

Improved methods of sealing project schedule forecast and intelligence maps that will reduce time of execution of works, which are on the critical path, transform tactical operational risks, reduce the loss of trained reserves, reduce wear vybiynoho additional equipment and maintain the safety of underground works.

List of sources

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