Research on risk dodges of industrial structure readjustment in mining industry city

It was mainly research on the causes, manifestations, and risk dodges of the industry risk selection, industry structure risk during the readjustment of the industrial structure and the establishment of the early-warning model of risk aversion. Supported by the National Natural Science Foundation of China(70572072); the Science and Technology Research Project of the Education Department of Liaoning Province(05L178, 20060382)     

水下振荡脉冲射流气举破碎器的研究

探讨了振荡脉冲射流作为气举破碎器的可行性。理论和实验研究了在淹没条件下振荡脉冲射流破碎硬土岩层和松动矿床的动态特性。振荡脉冲射流不仅能有效地破碎水下粘土层、松动矿床砂粒,而且能产生脉冲上举力,促使砂粒快速地进入气举吸头,气举速度以及气举管中砂粒浓度明显增大。     

Study on water resisting property of subsurface aquiclude in shallow coal seam mining

According to the characteristic of clay aquiclude of overburden, the proper simulation materials and proportions of mixture for simulating the plastic clay aquiclude layers were developed, and the plastic similarity conditions were setup. Thus, the similitude and simulation method in whole stress-strain was progressed. Furthermore, the simulation condition and material proportions in water reaction property and crack closing property were also put forward. Based on systematical tests, the development and distribution of mined cracks in roof and subsurface aquiclude was found and the stability of aquiclude was analyzed at all. At last, the key section and key index of aquclude stability was advanced. It is found that the movement of clay aquiclude follows the movement of the underlying bedrock layers. The basic caving mechanism of the overburden roof strata was also presented. Supported by the National Natural Science Foundation of China(50375026); the Key Program of Science and Technology of the Ministry of Education of China (204183); the Program for New Century Excellent Talents in University of China (NCET-04-0971)     

Control effect of fracture on hard coal cracking in a fully mechanized longwall top coal caving face

Through theoretical analysis, simulation test and practice, the law of a fracture’s influence on hard top coal press cracking was studied. The study focused on the relation between fracture and coal strength, top coal caving ability and work face layout. Based on the investigation of the fracture system, the control of press cracking was achieved by matching working face to fracture orientation to improve top-coal caving ability and recovery. The matching principle was pointed out: The top-coal caving working face should be perpendicular to or obliquely cross the primary fracture at a large angle, and cross the secondary fracture at a small angle. The rational match can increase the recovery ratio of top-coal and avoid rib spalling. The application of control technology on hard top coal press cracking was introduced at the longwall top-coal caving face. Supported by the Plan of Young Backbone Teacher of Henan Province; the Science and Technology Plan of China Coal Industry (MTKJ07-220); the Plan of Education Department of Henan Province (2007440004); the Plan of Science and Technology Department of Henan Province (072102240029); the Doctor Foundation of Henan Polytechnic University (648190)     

Pattern recognition prediction of coal and gas outburst hazard in the sixth mine of Hebi

Based on the systematical analysis influence factors of coal and gas outburst, the main factors and their magnitude was determined by the corresponding methods. With the research region divided into finite predicting units, the internal relation between the factors and the hazard of coal and gas outburst, that was combination model of influence factors, was ascertained through multi-factor pattern recognition method. On the basis of contrastive analysis the pattern of coal and gas outburst between prediction region and mined region, the hazard of every predication unit was determined. The mining area was then divided into coal and gas outburst dangerous area, threaten area and safe area respectively according to the hazard of every predication unit. Accordingly the hazard of mining area is assessed. Supported by the Project of China National “973” Program(2005CB221501); National Natural Science Foundation of China(50474010); Key Laboratory Science Research Project of Liaoning Education Bureau (20060372)     

Study on multi-component combustible gas explosive characteristics of high gas mine

Studied on multi-component combustible gas, methane mainly, explosion characteristics of high gas mine, obtained the rules of gas explosive limit that influenced by environment temperature, pressure, concentration of oxygen, other combustible gas, coal dust, energy of fire source, and the inert gas, proposed a new method of divide gas explosive triangle partition, and gave new partition linear equations. The gas explosive triangle and its new partition has important directive significance in distinguishing if the fire area has a gas explosion when sealing or opening fire area, or fire extinguishing in sealed fire area, and judging if there will be a gas explosion or other trend while fire extinguishing with inert gas. Supported by the National Natural Science Fund of China(50474010); the National “Eleventh Five-year Plan” Science and Technology Support Plan of China(2006BAK03B0503); the Fund of Education Department Liaoning Province(05L-174); the Fund of Education Department Liaoning Province (20060389)     

Study on the evaluation system for the coal safety management based on risk pre-control

The new type of risk management is process management. First, the hazard sources are identified before coal mine accidents occur, and then the pre-control measure and information monitoring method based on classifying the hidden hazard sources are given. Lastly, the risk pre-alarm and risk control method are confirmed, the management standard and management measure are used to eliminate the hidden hazard sources. In this study, an evaluation system is built to evaluate the result of risk management. Supported by the National Natural Science Foundation of China(70533050); the Eleventh Five-year Science & Technology Support Plan of China(2006BAK03B0703); the Ministry of Education Humanities and Social Science (08JA630083)     

Matter-elements model and application for prediction of coal and gas outburst

The theory and method of extenics were applied to establish classical field matter elements and segment field matter elements for coal and gas outburst. A matter-element model for prediction was established based on five matter-elements, which included gas pressure, types of coal damage, coal rigidity, initial speed of methane diffusion and in-situ stress. Each index weight was given fairly and quickly through the improved analytic hierarchy process, which need not carry on consistency checks, so accuracy of assessment can be improved. Supported by the National Natural Science Foundation of China (50534080); the Science and Technology Research Project of Chongqing (CSCT, 2006AA7002)     

Creep characteristic simulation of deep soft rock roadway and long-term mechanical analysis of lining support

By the generalized Kelvin creep model, rheological characteristics of deep soft rock and long-term mechanical behaviors of support structures were simulated. Mechanical deformation characteristics of support structures under different lining circumstances were also analyzed on the basis of deducing the relationship between the generalized Kelvin creep model and implicit creep equations in ANSYS FEM software. The results show that high stress of deep tunnels is the main factor in creep damage; the surrounding rock’s deformation binding effect due to lining increases as the thickness increases but the effect becomes very weak when it increases to a certain value; contact pressure on the lining decreases as its thickness decreases. Supported by Open Foundation Project of Education Ministry Key Laboratory about Mine Disaster Prevention and Control (MDPC0811); Research Project “Spring Bud Plan” of Shandong University of Science and Technology; Shandong University of Science and Technology Innovation Fund Grant (yca2008-04-01).     

Analysis on air-leakage law of goaf in condition of ascending mining for top-coal caving

Using the Jisan Coalmine’s top-coal caving for the 3_down coal seam with ascending mining as the project background, the air-leakage characteristics of the goaf was analyzed. Through data fitting of the in situ observation, the models of gas seepage, diffusion and air-leakage in the goaf were established in ascending mining. The Computation Fluid Dynamics software Fluent was used to simulate the air-leakage law of the goaf. The results of the numerical simulation provide a basis for the use of the technology of ventilation and fire prevention in the working face of an ascending mining, which ensures the safety in production in the working face of the top-coal caving for 3_down coal seam in the Jisan Coalmine. Supported by the National Natural Science Foundation of China(50704025); the National Science Fundation of Education Department in Shaanxi Province( 07JK318); the Planning Project of Excellent Talented Person of New Century Supported by Ministry of Education of China (NECT050874)     

A remining technology of underground coal gasification at Zhongliangshan Coal Mine

The field trail used a mixture of steam and air with various levels of oxygen enrichment. Steady conditions were achieved in the field trail which produced high quality hydrogen-enriched syngas. To understand and optimize the UCG process, a simplified heat and mass transfer model was presented, providing a predictive tool for temperature and the major constituents of the syngas production. The model is compared with the field trail measurements for air and two levels of oxygen enrichment, showing reasonable agreement for the channel temperature and product syngas concentration profile. Supported by the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of Chinese (02019); Anhui Province Science and Technology Tackling Key Project(08010202058)     

Disaster prediction of coal mine gas based on data mining

The technique of data mining was provided to predict gas disaster in view of the characteristics of coal mine gas disaster and feature knowledge based on gas disaster. The rough set theory was used to establish data mining model of gas disaster prediction, and rough set attributes relations was discussed in prediction model of gas disaster to supplement the shortages of rough intensive reduction method by using information entropy criteria. The effectiveness and practicality of data mining technology in the prediction of gas disaster is confirmed through practical application. Supported by the National Natural Science Foundation of China(70572070); the Liaoning Province Talents Fund Projects(2005219005); the Technology Key Project of Liaoning Province(2006220019)     

Research on hydraulic slotting technology controlling coal-gas outbursts

Measured to control serious coal-gas outburst in coal seam were analyzed by theory and experimented in test site. A new technique to distress the coal-bed and drain methane, called hydraulic slotting, was described in detail, and the mechanism of hydraulic slotting was put forward and analyzed. The characteristic parameter of hydraulic slotting was given in Jiaozuo mining area and the characteristic of validity, adaptability and security was evaluated. The results show that the stress surrounding the strata and the gas in coal seam is released efficiently and thoroughly while new techniques are taken, as slotting at heading face by high pressure large diameter jet. The resistance to coal and gas outbursts is increased dramatically once the area of slotting is increased to a certain size. In the process of driving 2 000 m tunnel by hydraulic slotting excavation, coal and gas outburst never occurre. The technique could be used to prevent and control potential coal-gas outburst in the proceeding of tunnel driving, and the speed tunneling could be as high as more than 2 times. Supported by National Nature Science Foundation of China(50534070); International Science and Technology Cooperation and Communion Key Project of Ministry Science and Technology of China (2005DFA61030); Natural Science Foundation of Henan Province (200510460014); Coal Mine Gas and Fire Prevention and Control Key Laboratory Foundation of Henan Province (HKLGF200708)     

The application of modern surveying technology in mining survey

With the unceasing appearance and widespread application of new surveying technology, the present age mining survey has meet huge change. However, lots of problems occurred while using the new techniques since the number of mine is large in China and condition of the mine district is complex, it in some sense influenced the mine exploitation and management of China. Summarized the present situation of new technical application in mining survey, including the advanced instrumentation equipment, the “3S” technology, the information and the network technology and the information fusion technology and so on, and analyzed the problems which exists in the current mining survey, it also provided new ways to present age mining survey from the sustainable development angle. Supported by the National Natural Science Foundation of China(40771159); the Science and Technology Plan Project of Liaoning Province (2007308003); the Open Research Fund Program of the Geomatics and Applications Laboratory, Liaoning Technical University(2007009)     

Research of prediction for mine earthquake basing on underground rock’s movement and deformation mechanism

Movement and deformation of underground rock include vertical dislocation and horizontal deformation, and the energy released by mine earthquake can be calculated basing on deformation energy. So put forwards the prediction for degree and spread of mine earthquake according to the underground rock’s movement and deformation. The actual number of times and spread of mine earthquake on site were greatly identical to the prediction. The practice proves the possibility of prediction for mine earthquake basing on the analysis of underground rock’s movement and deformation, and sets up new approach of mine earthquake prediction. Supported by the Education Research Project of Liaoning (20060388); Liaoning Technology University Project (06A07)     

A triaxial creep model for coal containing gas and its stability analysis

Triaxial creep tests on CCG specimens were systematically performed using a self-made creep seepage experimental apparatus for determining the creep law of CCG. An improved triaxial creep model of CCG was established on the basis of a Nishihara model and another visco-elasto-plastic model, parameters of which were fitted on test data. Furthermore, the creep model is validated according to the result of triaxial creep experiments, and the outcome shows that the proposed triaxial creep model can properly characterize the properties of various creep deformation phases of CCG, especially the accelerating creep phase. At the same time, the instability conditions of CCG were presented based on the discussion of the improved model’s stability in terms of stability theories of differential equation solution. Supported by the National Natural Science Foundation of China(50874124); the National Basic Research Program of China (973) (2005CB221502); the National Natural Science Foundation of China(50534080); the Natural Science Foundation Project of CQ CSTC(2008BA6028)     

蒙东地区输变电线路工程土类划分及工程经济意义研究

针对输电线路工程建设中定额岩土分类不清晰所造成的工程造价问题,基于对蒙东地区输电线路工程的多次地质勘察,根据工程现场开挖难易程度及《电力建设工程定额估价表—输电线路工程》、《岩土工程勘察规范》、《铁路工程岩土分类标准》等规范,按照土质松散程度、含水量、塑性指数、粒径大小、风化程度、裂隙发育程度等参数对蒙东土层进行了分类研究,分别将粉质黏土、粉土、砂土、砾石、岩石几种岩土体细化为多个等级。将各等级岩土体与电力建设工程中传统的土层分类对比,从而使岩土地勘报告能够直接与输电线路定额直接对应。按照所提出的岩土体分类方法,将蒙东线路工程土质进行归类分析,发现蒙东土层主要为《电力建设工程定额估价表—输电线路工程》中普通土和坚土,占整个土层分类的70%以上。     

Effective wave identification and interference analysis of the seismic reflection method in mines

Through discussion of the time-distance curve characteristics of the direct wave and from the front, side and rear of the reflection waves of the seismic reflection method for advanced exploration in mines, and analysis of several major interference waves in mines, the differences in time-distance curve, frequency, apparent velocity between the effective wave and interference wave in the seismic reflection method for advanced exploration are obtained. According to the differences, the effective wave is extracted and the interference wave is filtered and the system’s precision and accuracy is improved. Supported by the National Natural Science Foundation of China(50375026); the National Basic Research Program of China (2005cb221500); the National Key Technology R&D Program (2006BAK03B01); the National Natural Science Foundation Key Program (50534080)     

Analysis of faults stability with dynamic phenomena in the mine based on slide criterion and in-situ stress measurement

For the study on the relationship between the dynamic phenomena in the mining such as mine earthquakes, outburst and faults slide, firstly, double shear friction experiments of sandstone were made, and its slide criterion was suggested considering the viewing of engineering. Secondly, in order to study the stability of underground rock and zone of tectonic stress field, based on the analysis on distribution characteristic of initial rock stress measurements, the geology structural model was built and tectonic stress field was made a back-analysis by applying finite element method. The calculating results fit with the analysis result of earthquakes mechanism and the distribution characteristic of the measurements. The high stress regional centers station locates discontinuous zone of I level faults and is corresponding to underground earthquakes scene. From then it is certain that tectonic stress is the major origin and necessary condition of mine earthquakes. The instability slide of the faults is the main manifest and the mining activity is the leading factor. Beipiao fault has a dominate effect on other sub faults and tectonic stress area and is dynamical fountain of dynamic phenomena in the Beipiao Mines. Supported by the Project of China National “973” Program(2005CB221501); National Natural Science Foundation of China(50474010); Research Fund for the Doctoral Program of Higher Education(20040147005)