A New Mode of Coal Mining Under Buildings with Paste-Like Backfill Technology

The formation of the paste-like backfill technology was introduced briefly in this paper. From the actual cases of coal mines, a new mode of coal mining under buildings with the technology was proposed. And its specificity was analyzed, and a further introduction to the full-sand-soil solidifying material was given. The main parts of the backfill system, such as the backfill preparation system, the pipeline transportation system,the backfill systems in fully-mechanized mining faces and the backfill process, were presented emphatically.     

Study on Critical, Modern Technology for Mining in Gassy Deep Mines

To achieve safe and highly efficient mining in the gassy, deep mines of the Huainan collieries simultaneous coal and gas extraction, and the corresponding ventilation methods were developed. This includes a set of mining procedures and principles which help insure safe and efficient production. Furthermore, green mining, meaning the comprehensive use of emitted gas, proper treatment of the environment and appropriate mine temperature control, is now standard. The concepts of modem mining and the principles of pressure relief are described. Coal-gas simultaneous ex- traction and multi-pressure relief techniques were developed which require a combination of surface and underground gas extraction. The application of Y-ventilation systems, of roadways retained along goafs, of stress control techniques for highly fragile mine roofs and of powerful, automatic and reliable mining equipment contributes to safe operation of modem deep mines. Operating parameters for these techniques are described and the results of their use discussed.     

Prediction Technology of Buried Water- Bearing Structures in Coal Mines Using Transient Electromagnetic Method

Buried water-conducting and water-bearing structures in front of the driving head may easily lead to water bursts in coal mines. Therefore,it is very important for the safety of production to make an accurate and timely forecast about water bursts. Based on the smoke ring effect of transient electromagnetic fields,the principle of transient electro-magnetic method used in detecting buried water-bearing structures in coal mines in advance,is discussed. Small multi-turn loop configurations used in coal mines are proposed and a field procedure of semicircular sector scanning is presented. The application of this method in one coal mine indicates that the technology has many advantages compared with others. The method is inexpensive,highly accurate and efficient. Suggestions are presented for future solutions to some remaining problems.     

Study of “3-Step Mining” Subsidence Control in Coal Mining Under Buildings

Mining subsidence damage is the main factor of restricting coal mining under buildings. To control or ease effectively the degree of mining subsidence and deformation is essential to resolve this problem. Through analyzing both advantages and disadvantages of some technologies such as mining with stowing, partial extraction and grouting in separated beds of overburden, we used the principle of load replacement and propose a “3-step mining” method, a new pattern of controlling mining subsidence, which consists of： strip mining, i.e. grouting to fill and consolidate the caving zone and retained strip pillar mining. The mechanism of controlling mining subsidence by using the “3-step mining” pattern is analyzed. The effect of the control is numerically simulated. The preliminary analysis shows that the “3-step mining” can effectively control ground subsidence and deformation. By using this method, the ground subsidence factor can be controlled to a value of about 0.25. Coal recovery can reach 80%-90%. Coal mining without removing surface buildins can be realized and the economic loss resultin from round subsidence can be greatly reduced.     

Study of 3-D Numerical Simulation for Gas Transfer in the Goaf of the Coal Mining

In order to simulate field distribution rules,mathematical models for 3-D air flows and gas transfer in the goaf of the coal mining are established,based on theories of permeability and dynamic dispersion through porous media. A gas dispersion equation in a 3-D field is calculated by use of numerical method on a weighted upstream multi-element balance. Based on data of an example with a U type ventilation mode,surface charts of air pressure distribution and gas concentration are drawn by Graphtool software. Finally,a comparison between actually measured results in the model test and the numerical simulation results is made to proves the numerical implementation feasible.     

Simulation Analysis of Coal Mining with Top-Coal Caving Under Hard-and-Thick Strata

1 Introduction A large amount of coal seam with hard coal and hard roof exists in the east mining area of China, such as in the representative mining area of Xuzhou, where the hardness is relatively large (f >2); the roof is hard and the thickness is relatively large (about 20 m). Two key problems must be solved for the suc- cessful application of fully-mechanized coal face with top-coal caving technology: the first is the top-coal falling ability and the second is the control of the hard-and-…     

Analysis of Discharge Spark Energy in Buck Converter of a Continuous Mode of Inductive Current

The basic idea of intrinsically safe circuit and the discharge spark in the Buck converter in the explosive atmospheres were introduced. The Buck converter is the main topological structure of the switch type of intrinsically safe circuit, which has two working modes： continuous inductive current （CCM -- continuous conduction mode） and discrete inductance current （DCM -- discontinuous conduction mode）. The operating state of the continuous inductive current mode is analyzed in detail and the energy of discharge spark in various operating modes is discussed. The total energy will decrease with the increase of switch frequency, in a switching cycle; the discharge spark energy has a maximum and a minimum value. Therefore, the Buck converter has smaller discharge spark energy than the linear power circuit and the switch type of intrinsically safe circuit can enhance the output power and the conversion efficiency of the intrinsically safe power.     

Application Research of Computer Network Technology in Mining Railway Transport Management System

This paper discussed the necessity of establishing a computer network in a mining railway transportmanagement system. The network structure and the system security design, associated with the real develop-ment condition of a mining area, were brought forward, and the system evaluation was given.     

Application of 3D Seismic Data Inversion to Coal Mining Prospecting

1 Introduction3D seismic prospecting plays important roles incoal mining because of it necessity to geologic sur-vey. Owing to using many new theories and tech-nologies, the resolution of 3D coal seismic prospect-ing is increased continuously, the geological structurecan be detected more and more accurate. ButRayleigh's criterion shows that the resolution thresh-old of the seismic reflection wave is λ /4 (λ iswave length of seismic wave ).The resolution of logging data is very high, andit c…     

梁洼矿区房屋“超限”裂缝原因的探讨

梁洼煤矿西部的军营沟矿井开采时，在采用６３°的移动角圈定的影响范围之外，部分建筑物仍旧出现了裂缝。本文在实地调查的基础上，根据房屋的结构特征和房屋损害现象，指出了竹茂村房屋裂缝的原因，同时求得了梁洼煤矿军营沟矿井的移动角和边界角值。     

Fault Diagnosis Approach of Local Ventilation System in Coal Mines Based on Multidisciplinary Technology

In order to reduce the probability of fault occurrence of local ventilation system in coal mine and prevent gas from exceeding the standard limit, an approach incorporating the reliability analysis, rough set theory, genetic algorithm （GA）, and intelligent decision support system （IDSS） was used to establish and develop a fault diagnosis system of local ventilation in coal mine. Fault tree model was established and its reliability analysis was performed. The algorithms and software of key fault symptom and fault diagnosis rule acquiring were also analyzed and developed. Finally, a prototype system was developed and demonstrated by a mine instance. The research results indicate that the proposed approach in this paper can accurately and quickly find the fault reason in a local ventilation system of coal mines and can reduce difficulty of the fault diagnosis of the local ventilation system, which is significant to decrease gas exploding accidents in coal mines.     

Research on 3D Modeling and Visualization of Coal Pillars for Surface Protection

In order to safely exploit coal resource, protection coal pillars must be prepared in coal mines. Some correlative parameters of protection coal pillar are calculated by Drop face and Drop line methods. Models of protecting surface objects and coal pillars are established by TIN modeling and object-oriented technique. By using ACCESS2000as the database and the VC＋＋ and OpenGL as the language, the calculation of protective coal pillars is realized and the 3D-visulizaiton system for protected objects on ground surface and for coal pillars is developed. The system can obtain the data of characteristic points on the surface interactively from the digitized mine topography map, constructing 3D model automatically. It can also obtain the interrelated parameters of the coal seam and drill hole data from existing geolog!cal surveying database to calculate the location, surface area and the total coal columns. The whole process can be computed quickly and accurately. And the 3D visualization system was applied in a mine, showing that the system solve the problem of complex calculation, not only realized the automatic 3D mapping and visualization of coal pillars for buildings protection, but also greatly improves the working efficiency.     

Analysis and Research of Factors Affecting Coal Mining with Plough

Coal mining with ploughs is an ideal coal mining technology for thin and thinner coal seams.The cxistenec conditions of coal scams are different for cach other,which affeets coal mining with ploughs to different dcgrees,and the application results are also different.The authors analyzc the affeeting factors by means of mathcmatical methods.The research is useful to the application of ploughs.     

高瓦斯“三软”厚煤层综采放顶煤开采技术分析

通过对高瓦斯“三软”5m厚煤层综放工艺开采理论探讨和实践，得出安全生产技术管理经验，为综放工作面的安全生产和高产高效提供保证。     

An Entrapment Model of Water Flow on Fine Coal Flotation

Effect of entrapment of water flow on fine coal flotation was studied. The relation between constant of water flotation rate and flotation time was investigated and the water recycling model determined. The entrapment model of water flow about the relation between the recovery of fine particle and that of water in concentration was established. Finally, the equation about ash in fine clean coal at any time was derived by introducing a de-ashing coefficient.     

Reliability Analysis of Production System of Fully-Mechanized Face Based on Output Statistic

Production system of fully-mechanized face is a complicated system composed of human, machine and environment, meantime influenced by various random factors. Analyzing the reliability of system needs plentiful data by means of system faults statistic. Based on the viewpoint that shift output of fully-mechanized face is the result of various random factors＇ synthetical influence, the process of how to analyze its reliability was deduced by using probability theory, symbolic statistics theory and systematic reliability theory combined with the concrete case study in this paper. And it has been proved that this method is feasible and valuable.     

Application of 3D Visual Techniques in Daliuta Coal Mine

3D visualization is one of major problems in ＂Digital Mine＂ theory and its technological research field. Through the observation of 3D geological models, spatial structural information, connected with the information of production management hidden in geological data, could be detected. In order to meet the requirement of more efficient coal exploration, a case study of geological characters of the Daliuta Coal Mine is presented in which 3D visual models of the ground surface and geologic bodies are established on the basis of data models and data structures of 3D geology modeling. The main conclusions of this study are as follows： （1） Through analysis and organization of spatial discrete data, the drillhole database is designed with the data of the Daliuta mine; the connections amomg drillhole data are realized and displayed in a 3D environment. （2） Combining real data of the Daliuta mine, drillhole visualization is realized in a 3D environment by using the CoalMiner system. （3） The ground surface modeling of the Daliuta coal mine adopted a surface-data model and a TIN data structure. （4） 3D models of coal seams and rock formations of the Daliuta mine are established, which provide a method for the simulation of complex surfaces of geologic bodies. In the end, the models are applied to the Daliuta coal mine and the result shows that better geological effects are obtained.     

Application of Catastrophe Theory in 3D Seismic Data Interpretation of Coal Mine

1 IntroductionCatastrophe theory is a new mathematics subjectdeveloped in 1970s, which is part of nonlinearscience and a branch for studying discontinuousphenomenon. Seven elementary catastrophe modelshave been developed, including fold catastrophe, cuspcatastrophe, swallowtail catastrophe, elliptic umbiliccatastrophe, hyperbolic umbilic catastrophe, butterflycatastrophe and parabolic umbilic catastrophe[1-8].Generally speaking, catastrophe theory means cuspcatastrophe model which categorizes …     

放顶煤综采采空区“三带”的理论计算与观测分析

本文应用非线性渗流理论建立采空区流场二维平面非线性渗流流函数微分方程,利用有限元技术求得各结点上的流函数值和各单元上的流速v_x、v_y、v_o在此基础上,得到采空区风流流线和等速线。依据煤自燃所对应的风速上下限,得到放顶煤综采采空区不自燃带、可能自燃带和窒息带的形态和范围。对采空区矿压显现、采空区温度变化及氧浓度变化进行的观测表明,理论计算与实际观测所得结果基本一致。