Advanced Materials Research Vols. 616-618

Abstract: According to the gas dynamic theory, this paper deduces the approximate calculation formula on elastic energy of a tons of coal through theory analysis, and then gets the quantitative calculation method between incident overpressure and reflected overpressure of the coal and gas outburst shock wave. The calculation formula in this paper is in line with the measured values, and so its validity has been verified. The analysis result shows that the effect of the elastic energy during the process of coal and gas outburst should be considered when the depth of the coal seam is great and the coal’s modulus of elasticity is small.

Abstract: With the rapid development of ARM-core chips and the popularity of USB camera, composing of real-time monitoring system with these two together becoming a trend, meantime the open-source Linux operating system is just as a bridge between the two. This paper studies on ARM9 nuclear processor S3C2440 for CPU, Linux as embedded system , by using USB camera for image acquisition hardware and software implementation process，and ultimately composing of a video acquisition and displaying system for coal mine ,and this system is applied in underground coal mine belt conveyor belt of longitudinal tear detection .

Abstract: According to the specific geological conditions in themulti-layer worked-out areas of Yongding coal seam, by the methods of integration of theoretic analysis, numerical value calculation and so on, we studied movement law of Overlaying Strata and influence of coal pillar in Coal seam mining, obtained the basic law of the overlying strata movement in multiplayer, provides a theoretical basis for the safe and efficient exploitation of the success of multiplayer. Many mining area in China is mining of closed distance coal seam group, By the impact of coal seam in the overlying, face and the tunnel roof structure will be different injury in sub-coal seam mining, Roof structure has changed greatly, even damage and easily take the roof leakage, When the the goaf communication with the overlying coal seams, caused by the induced secondary disasters such as face air leakage, Therefore, exploitation of the law of motion of the overlying strata in the multiplayer is a pressing problem. Exploitation multiplayer seam few theoretical and technical foundation at home and abroad, affecting the validity of the mining, rationality. although a lot of research on theory and technology of coal mining over the years[1~5], But it was not able to an overall comprehensive analysis of upper goaf adjacent goaf and overlying the coal pillar and present mining face, create a dynamic structural mechanics model, which is likely to cause the occurrence of disasters.

Abstract: By making full use of the advantages of strip mining method and full-pillar mining method, the wide strip and full-pillar mining method can achieve the aim of mining under villages. However, at the full-pillar mining stage, the difficulty in managing several workfaces which are at work at the same time still exists. To improve the wide strip and full-pillar mining method’s applicability, an optimization of extraction sequence for coal pillars instead of the multi-working-face is put forward at the stage of full-pillar mining, and in the case of the deformation limit of surface structures is satisfied, to extract all the coal pillars which are under villages. By specific analysis of the extraction sequence optimization of the coal pillars in No.1 mine under Qian Xudapo village which belongs to Chang Chun coal Co., LTD., a better result is got which also acts a technological reference for the extraction under villages.

Abstract: The hydrocarbon source rocks in Denglouku formation of Northern Songliao Basin are mainly the grey mudstones in Deng 2 member. Combined with well and seismic information, this paper forecasts the mudstone thickness distribution of study area applying multiple seismic attribute quantitative prediction based on sedimentary characteristics. We also predict the plane distribution of dark mudstone-mudstone thickness ratio with stratigraphic sedimentary thickness information, horizontal result of seismic facies interpretation and dark mudstone-mudstone thickness ratio materials of well point. Eventually, we obtain the plane dark mudstone prediction result. Analysis indicates that the source rocks of Deng 2 member in Northern Songliao Basin mainly consist of three larger dark mudstone development areas and other sporadic small-scale development areas adjacent, which have the maximum dark mudstone thickness of about 357m located near Songji 6 well.

Abstract: Key factors affecting the control of roof fall and rib spalling are identified relying on the statistics for characteristics of roof fall and rib spalling distribution, and the regression analysis of the relationships of roof fall and rib spalling to support parameters by measuring actual ground pressures. The effect of support in controlling roof fall and rib spalling is analyzed by setting up a caving arch mechanical model of cataclastic coal and rock mass on fully mechanized caving face, and the key parameters of support are also determined using numerical simulation.

Abstract: There are many factors that affect the gas emission in working face. To predict and prevent this kind of gas emission, the mainly sensitive factor should be filtered and detected from many influencing factors. Taken Dashuitou Mine for an example, the main influencing factor was analyzed by using Grey correlation theory, which was atmosphere pressure. Then, the relationship between atmosphere pressure and gas emission is studied with Statistics tools. It obtained some important conclusions, include the rule of Atmospheric pressure changes in working face during a day, rule of the gas underground changes in a day, rule of correlation statistical, concrete relation between atmospheric pressure and gas emission. It would be useful on disposing of gas emission risk.

Abstract: In underground engineering, soft rock underground cavern problems are often found. Based on the basic principles of underground engineering support, by support strength from the technical specification and practical observation data, we can reach a conclusion on the basis of soft rock underground cavern stability with lower confining pressure controlling measures. The supporting force is 3MPa in average, the max value of the supporting force is 9MPa. The supporting forces belong to the range of lower confining pressure.

Abstract: This paper presents results of a comprehensive study involving analytical and field experimental investigations into the factors controlling the hydraulic fracturing process. Analytical theories for fracture initiation of vertical and horizontal borehole are reviewed. The initiation and propagation process of hydraulic fracturing is performed in the field by means of hydraulic fracturing and stepwise hydraulic fracturing, the effect of factors such as in-situ stress and rock strength on fracture propagation process is studied and discussed. The fracture initiation pressures estimated from the analytical model and field experiments are compared as well as the fracturing process during case 1and case 2. Results from the analytical model and field experiments conducted in this study are interpreted with a particular effort to enlighten the factors controlling the hydraulic fracturing process.

Abstract: In order to research the application extension of the viewpoint of the four key factors controlling formation process of lithologic traps, the paper was dissected lithologic reservoir dynamically, mainly analyzing the paleo-fluid dynamics, paleo-hydrocarbon migration pathway, paleo-critical physical properties of reservoirs and paleo-sealing conditions of the traps in formation of hydrocarbon accumulation period. The results show that they recover the limited and most important factors for formation of lithologic traps and come back the formation process of lithologic traps availably, and it also can used to be evaluated low exploration basin dynamically, compositely analyzed key factors controlling formation process of lithologic traps and selected advantaged target area. The application of this methodology indicates that it could be widely used in the dynamic formation of lithologic traps and dynamical evaluation of low exploration basin in Hongliuquan area, Qaidam basin.