Coal and gas outburst disaster early warning andemergency response decision support technology

In order to realize early warning of coal and gas outbursts, and take timely emergency response, the technology of coal and gas outburst early warning and emergency response decision support is brought forward. The characteristics of abnormal gas outburst are specially analyzed, thus methods are given to monitor and identify the coal and gas outburst disaster. Combined with existing safety monitoring system in the mine, researches of such techniques are carried out as outburst gas content predicting, spread range forecasting and regions of power cutoff. Through those techniques, the Daping coal mine gas explosion disaster is retrieved. In the process of simulation, gas spreading early warning and related emergency response proposals can be issued before the gas arrive.     

RESEARCH ON THE MECHANISM OF GAS OUTBURST INITATION IN MINES

The mechanism of coal-gas outburst iniration is comprehensively analysed. The direct courses of initating coal-gas outburst are the sudden loss of confining stresses and the gas pressure gradient in coal seam. The effects of working face's advancing rate, geological conditions and gas pressure gradient as well as mechanical & physical characteristics of coal on outburst initation are expounded by means of mathematic analyses about gas seepage which takes place in coal seams. The results are of certain practical significance and reference value to further quantitive study of outburst and its predication.     

Key Layer and Stress Dike Mechanism of Coal and Gas Outbursts

The outburst coal mass is a geologic body which had objectively existed before outbursts occurred.The authors think the occurrence and development of coal and gas outbursts are controlled by comprehensive factors according to a host of facts of outbursts in their researches,and all the factors belong to the system of "rock coal gas rock".Therefore the authors put forward a completely hypothesis,i.e.key layer and stress dike mechanism of coal and gas outbursts.This hypothesis emphasizes that the outbursts are the result of comprehensive action by coalbed gas,abutment stress and physical and mechanical properties of coal.Of special interest is emphasizing the geologic backgroud and conditions of outbursts to a great extent.Any phenomenon of outbursts which a person could observe could be qualitatively explained with the hypothesis so that the hypothesis can serve the study of geophysical field of outbursts perfectly.     

近水平复合煤层露天矿备采煤量留设位置与保有期优化

为了确定经济合理的露天矿备采煤量留设位置和保有期，运用露天开采基本原理与统计分析方法，分析新时期露天煤矿的发展变化特点及其对备采煤量留设位置和保有期的影响；以经济效益最优为判断准则，研究复合煤层露天矿备采煤量留设位置与内排运距的关系，建立备采煤量留设位置优化模型；研究季节性剥离露天矿备采煤量保有期与剥离成本、运输成本以及资金时间价值的关系，建立备采煤量保有期优化模型。以内蒙古东部地区某露天矿为研究实例，确定了该矿经济合理的备采煤量保有期为6.5个月，备采煤量应全部留在1号煤层。研究结果表明：该优化模型可用于指导露天矿生产，有效降低剥离成本，提高经济效益。     

Triaxial creep model and its stability analysis of gas containing coal 

Investigation on the creep property of coal containing gas is an effective means for understanding the mechanism of delay outburst of coal and gas in a coal mine. This paper conducts triaxial creep tests on the specimens of gas containing coal using a self made creep experimental apparatus to determine the creep law for coal containing gas. An improved triaxial creep model is developed for containing gas by coupling a Nishihara model with another visco elasto plastic body which can describe the deformation property of non Newtonian fluids. The parameter fittings are conducted based on the experimental dada.The present model is examined in terms to the results of triaxial creep tests in various stress level cases. The result shows that the proposed model for gas containing coal can properly represent the creep deformation at different creep stages, especially at the accelerating stage. The instability condition of the model for coal containing gas is also discussed according to stability theories of differential equation solution.     

The Quantitative Analysis of the Fatalness of the Methane Explosion in Coal Mines

If the quantitative index of the methane explosion in coal mines before exploding can be calculated, the measure will be take to prevent the methane explosion. The methods using in the analysis of the fatalness of the methane explosion are almost qualitative analysis. In this paper the quantitative analysis of the fatalness of the methane explosion in coal mines is achieved on the basis of the research of the essence event probability with the method of fault tree analysis using the micro-computer. The practical example of the quantitative analysis of the fatalness of the methane explosion in coal mines is given.     

Mechanism and application of protection againstoutburst for abrasive water jet slotting technology

Aiming at the status quote of long time for methane extraction and slow speed for laneway excavating in coal seams of Liziya south 2JHJ well, abrasive water jet slotting technology is adopted to improve the methane desorption and increase excavating speed in semi-coal laneway. Through analyzing damage model and protection against outburst mechanism, the process of Coal-Rock Mass being cut and fractured is studied. Through lab test on abrasive water jet cutting coal-bed gangue, a new abrasive water jet cutting device is successfully designed and made and all parameters are determined. It is showed that abrasive water jet can cut through a coal-bed gangue with thickness 60~80 mm and uniaxial compressive strength 62 MPa. After cutting coal seams by abrasive water jet, the surface area for methane is enlarged and then coal seams pressure fell rapidly. Therefore the permeability and desorption of coal seams are greatly increased. The results are as follows: the average productivity of single-hole was enhanced by 2.83 times.     

A visco elasto plastic creep model of outburstprone coal under triaxial compression

Using self made creep seepage experimental apparatus, triaxial creep tests on outburst prone coal are carried out with coal samples taken from Songzao Coal Mine. It is found that the attenuation creep property is shown in the conditions of less than its long term strength load, while non attenuation creep property for the greater conditions. By introducing a visco elasto plastic body which can describe the deformation property of non Newtonian fluids, the visco elasto plastic creep model of outburst prone coal is put forward combined with a Poyting Thomson model. The model parameters were fitted out with Matlab programmer and validation is employed. It is found that the test results were in good agreement with those by the proposed model.     

The Study of Outburst-proneness of Coal Seam Via Experiments and fuzzy Comprehensive Judgement

The four existing autburst-proneness indexes and a modified outburst energy index W were applied to study outburst-proneness of coal seam via exprements; the fuzzy mathematics method was used for fuzzy comprehensive judgement on outburst-proneness of coal seam;the results obtained in experiments were identical with engineering practice.     

Problems of Ecological Security in Coal Mines and Countermeasures

Disordered mining activities have destroyed ecosystem of coal mines and threatened local ecological security. Ecological security problems in coal mines mainly involve pollution, biology, ecosystem and landscape. To solve these problems, this study gave countermeasures from the perspective of policy management, technical support and public participation, especially public participation helps restore the damaged eco-environment and guarantee ecological security of coal mines     

河北板栗、金丝小枣和红小豆品质气候与品质预报

对板栗、金丝小枣和红小豆的主要成分进行了分析鉴定,确定了它们的品质等级分类标准。通过诸多气象因子的分析筛选,建立了相关气象因子预报品质的数学模式和计算机(图形输出)模式。     

THE STUDY OF THE RELATION BETWEEN COAL-GAS OUTBURST AND PHYSIC AND MECHANIC PROPERTIES OF COAL SEAM IN A COAL MINE

The experimental study of physic and mechanic properties of coal seam in a coal mine is presented, and the relation between coal-gas outburst and the strength, the elastic modulus, as well as the deformation property of coal seam is analysed on the basis of the experimental results.     

Study on Adsorption Characteristics of Coal to Gas in Geophysical Field

It is very important to mine safe exploitation, gas drawing and predict of coal and gas outburst that adsorption characteristics of coal to gas in geophysical field are studied. Adsorption and desorption characteristics of coal to gas in geophysical field have been reviewed in detail, then it is obtained that adsorption characteristics of coal to gas in electromagnetic field should be further studied . Adsorption and desorption characteristics of coal to methane in alternating electric field (AEF) have been studied mainly. Adsorption characteristics of three coal samples in AEF have been studied by means of Volume Method. The result shows that chemical properties and matter constituent of coal surface are no changed , adsorption and desorption of the coal samples in AEF well accord with Langmuir equation and two constants empirical formula, and because coal potential energy is increased and coal temperature is raised caused by Joule heat effect , adsorption ability of coal is decreased, and the desorption process is slowed down in AEF.     

Wind Damage Estimation and Prediction of Light Steel Industrial Buildings

Wind hazard damage estimation was addressed for light steel industrial buildings which were the typical wind vulnerable structures in southeast coastal cities. With parametric analysis of wind damage and the structural failure features, the envelop elements and the connecting elements were determined as the pivots of the damage analysis. Upon the consideration of the co effect of exterior wind pressure, wind induced internal pressure and windborne debris damage, a typhoon load model was proposed. And with the calculation method of the element resistance from the regulation, the procedure of the damage estimation was described and the damage classification of industrial buildings was specified with detailed indicators. Finally, the proposed method was approved with the actual data of typhoon CHANCHU (0601).     

农村户用沼气综合利用的经济效益评价

根据农村户用沼气的综合利用模式,以煤炭作为沼气的替代能源,利用成本—收益法分析利用的经济指标,分析结果表明：沼气综合利用的经济效益显著,项目的抗风险能力较强,具有大力推广的价值。     

露天矿相邻采区间内排压帮高度及 重复剥离深度的综合优化

分析了不同压帮方式的内排运距特点与计算原理,建立了内排压帮高度及重复剥离深度的数学模型,得出通用的计算公式并给出有效判据。以黑岱沟露天矿为例,采用费用补偿法确定最优的内排压帮高度,利用最小重复剥采比确定最佳的重复剥离深度。研究结果表明：分区开采露天矿相邻采区间内排压帮高度与重复剥离深度需同时确定,以费用补偿法建立的数学模型简单且可靠,研究成果对露天矿相邻采区间生产设计具有指导意义。     

Study on the Chemical Composition and Macromolecular Structure of Outburst Zone Coal

In the light of ultimate analysis data and density of specific gravity liquid, we put forward a formula to calculate the real density of vitrinite, and get a relatively exact computational formula of condensation ring index. The molar fraction of carbon atom ( x C ) could be used to describe the metamorphic degree of coal. Relationship between the macromolecular structure and the probability of coal outburst has been discussed.     

Studies on the Structure Model of Coal and Its Polarization Characteristics

The macromolecular structures of coal samples collected from Yutianbao, Nantong and Qingnian coal mines in Sichuan were studied and a model of structure for these coals was set up. On the basis of above mentioned work,experimental studies and theoretical analyses were made to investigate the characteristics of coal polarization in applied electric field. The results indicate that the rotation polarzation and the space polarization are the essential reason for the attenuation of electric current through coal samples,and that the space polarization is the main form of coal polarization.     

富硒猪肉脯生产中HACCP体系的建立

对富硒猪肉脯生产过程中各个环节可能存在的潜在危害进行了分析,根据HACCP原理确定了相应的关键控制点(CCP)和关键限值,并制定了相应的预防措施,建立了监控方法,将加工过程中的危害风险降低到最低程度,从而最大限度的提高富硒猪肉脯的食用安全性。     

Damage Analysis on Coal and Rocks and the Method of the Checking Damage by the Deviator Stress

The characteristic of the original damage and the breaking of the coal and rocks under the loading has been discussed by a lot of microscopic structure analysis and by whole stress strain testing on the coal and rocks. The non homogeneity causes the stress locating in a small spot. It is the essential cause of the damage developing and causing the structure breaking of the coal rocks. The failure of brittle fracturing, rubbing later on and granulating should be a major pattern in the outburst of coal and gas. The method of the examining damage by the deviator stress, is proposed. It can be used to analyse the characteristic of the coal and rocks.