Stability Evaluation of Roadway Design

Abstract: This paper focuses on the stability of coal mine roadway design evaluation index system was studied, first outlined the concept of Coal Mine Safety Evaluation and development, and discusses the stability evaluation of Roadway design method, the last coal mine roadway from four aspects Stability design of specific indicators.

Keywords: Stability Evaluation of Roadway
1 Overview of Coal Mine Safety Assessment
1.1 The concept of safety assessment
Safety Assessment, also known as risk assessment or risk assessment, the English as a Safety Evaluation, referred to as SE, the system safety assessment is to assess the potential risk to a reasonable solution to ensure the safe operation of the system of systems approach. Specific , the safety assessment to do the work in three areas: first, to run on specific aspects of the project in accordance with its investigation or process step by step, find out the potential danger, and the analysis of these potential dangers, then, according to the results of the analysis for different ratings for different potential hazards, it is best to make use of quantitative values that last, according to the results of the corresponding rating of the potential dangers of reasonable and effective countermeasures and measures to ensure that the intended target of the project in accordance with running smoothly. for enterprises of coal production, coal production safety is the most important business issues to run, so the safety of coal production safety evaluation of the sub-project is particularly important.

1.2 Safety assessment of coal production history and development of
Coal production enterprises in China had undergone a safety assessment from small to large process back in the eighties, Ministry of Coal Industry on the development of the <<Mine Ventilation Assessment of quality standards and inspection methods>> and < <standard of quality standardization of Mine>>, the former as a coal mine production safety supervision department of mine ventilation and safety checks on the safety standards are widely used, which also serves as the Industry standard for the coal Industry has been seriously implemented. In 1994, the relevant departments of the < <production quality standardization Biaozhun Mine>> has been revised so that it has been further improved, the revised covers mining, ventilation, transportation, gas, and excavation of five, at present it is still the most widely used in coal mining enterprises security evaluation criteria. At present, for the safety evaluation of coal enterprises focused on institutions of higher learning, the Research focused on mine safety MIS system (management information systems, on the safety assessment of the theory and technology is still relatively weak.

2 Evaluation of Roadway Design Stability
2.1 The principles of evaluation design
Evaluation design should adhere to a comprehensive, systematic and scientific principles, the first is comprehensive, affecting the stability of coal mine tunnel there are many factors in determining the scope of the study evaluation, be as much as possible indicators of the impact of various aspects of to be investigated included. the only way to ensure that the final evaluation factors selected to maximize the representative of the overall situation, to prevent the "leaf cover of wood," the situation, followed by the systematic and systemic requirements of a comprehensive evaluation index can impact of coal on the basis of the roadway to seize the main factor, another evaluation must not only be able to accurately reflect the relationship between factors and indicators, and to be able to reflect the relationship between factors, so as to enhance the credibility of the evaluation and, finally, science, scientific evaluation required to adhere to the scientific and objective principles, best efforts to reflect the objective reality and evaluation of the nature of things. The design of the evaluation index, can be quantified as far as possible quantified, so easy in the data collection information transmission does not occur when the information distortion, the index can not be quantified, qualitative evaluation can be used and the level of evaluation results, so as to make assessment results more realistic and effective.

2.2 Design of Roadway stability index
Rating index main methods for the design synthesis method and analysis, synthesis method is "bottom up" approach, comprehensive method requires first to find out the stability of the roadway Colliery factors, then these factors Julei finishing, and finally to summarize the clustering of specific indicators. of the opposite principle, the use of the "top down" approach, analysis requirements of the first goal of the analysis is divided into categories according to the specific number of sub-goals, and then handle target specific factors broken down into different sub-sub-goals, the last of these sub-sub-goals and then target specific expression. mine tunnel is a complex production system, the stability of the roadway is not only related to the environment, but also and people with mechanical close, so the roadway can be said to be potentially dangerous environment, and the result of mechanical interaction. For such a complex system, using analysis method is more conducive to evaluation design. reposted elsewhere in the Research Papers Download http: / / www.hi138.com 3 Evaluation of Roadway Design Stability
In this paper, analysis method, the first indicators of the stability of coal mine tunnel is divided into three broad categories: indicators of geological conditions, construction of supporting indicators and targets, and then further refined, and ultimately form a complete evaluation index system.

3.1 Geological Conditions Index
Indicators of specific geological conditions, including rock structure, lithology and groundwater surrounding the three indicators of impact. �� rock structure indicators: This indicator on the distribution of coal mine roadway to evaluate, for the layered structure of the rock, its bedding surface constitutes a potential separation surface (called the weak side, weak side of the trigger factors prone to cave. As thin layers of rock strata with intensity, bedding plane spacing of small features, so its easier to cave , for the strength and thickness of a large rock in terms of rock will be more stable. In addition, in fractured rock has a direct impact on the stability of the roof. �� surrounding rock Indicators: This indicator of the rock itself, the inherent properties were evaluated. rock mechanical properties is the stability of coal mine tunnel one of the main factors, while the mechanical properties of rock and rock is closely related to lithology. For low-intensity rock rock (such as most clay rocks, its support for coal mine roadway capacity from small, when mined after the media, the surrounding rock can not be self-supporting, often have such phenomena as roof fall. �� groundwater impact indicators: This indicator on the evaluation of the situation surrounding groundwater, groundwater impact on the strength of rock large rock in the water erosion, the rock mass strength will be greatly reduced. This is mainly because: first, the role of groundwater has deliquescence will small pieces of rock falling to the slow, the damage will eventually lead to falling on top of the second, groundwater makes the coefficient of friction between the rock fractures decreased, and promote the further deformation of the fracture, the third, the role of ground water wedge will produce tension within rock fractures, increasing the rock fractures, the fourth, groundwater can also lead to volume expansion of the rock, leading to collapse also.

Protection Index 3.2
Supporting the specific indicators, including support means supporting material parameters, and to pay three indicators, �� support style indicator: This indicator of the effectiveness of the selected payment method to evaluate a variety of supporting a variety of ways, according to payment of material differences can be divided into bolting, metal stent support, timber shoring, concrete or shotcrete support, etc., the choice of payment is not the intensity the higher the better, in general, the higher the support intensity, the need to support the higher costs will result in a waste of money and materials. Therefore, to provide supporting strength needed to stabilize and maintain the roadway to match the intensity, so as to get the best efficiency. �� indicators support parameters : Evaluation of the indicator support parameters Shiji ability to meet the needs of theory to support strength, such as support for the use of bolt, the bolt support parameters ���� support density, bolt length and diameter. �� Supporting Materials index: The index of the coal mine roadway evaluation of materials, supporting materials, will have a direct impact on the quality of support, such as support for the bolt, the concrete used to support whether the target is very important, good concrete can improve the stability of the roadway.

3.3 Construction of indicators
Specific targets include the construction of indicators of construction methods, construction technology indicators and indicators of roof area, �� index construction method: The main roadway on the tunneling method used to evaluate. Tunneling boring machines generally use tunneling or mining into the gun, under normal circumstances, the use of post- persons than the former extent of the damage on the small roadway. �� construction technology indicators: the index of the construction steps and parameters of the rationality and effectiveness of arrangements for evaluation. The main technical specification requirements for safety inspection, driving rate parameters are reasonable and so on. �� roof area of indicators: This indicator evaluation of roadway access and the intersection of the roof area, these two most likely to cause damage to the roof, the roof area is greater, the higher the likelihood of being damaged, therefore, to reduce it as much as possible two of the roof area, or focus on strengthening its support, the only way to improve the stability of the roadway.

References:
[1] Guo coherent. Mine tunnel roof stability bolting monitoring methods. <<Coal Support>> In 2009 3.

[2] Tanghai. Mine roadway fault identification. <<MINING Research "> In 2009 4.

[3] Tian, and. Mine tunnel security system through Research and practice. <<SAFETY AND ENVIRONMENTAL PROTECTION "> In 2009 3. Links http://www.hi138.com Research Papers Download