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Geochemistry and mineralization of Novaky coal seam
Verbich Franti?ek
Acta Montanistica Slovaca , 1998,
Abstract: The mineralization and geochemistry of the most important Slovak coal deposit in Novaky was intensively studied in the past. The favourable geological conditions create rich mineral association. There are different minerals in the deposit and they are responsible for the enhanced content of some elements in the coal. The summary of notions about geochemistry and mineralization of the coal seam with the emphasis on the main harmful elements sulphur and arsenic and their spacial distribution are studied in this paper.
Controlling Effects of Surrounding Rock to Coal Seam Gas Occurrence  [PDF]
Laibin Wang, Shiwen Zhang, Jinshan Shen, Zhongwen Zhang, Xiaotong Yang
Open Journal of Geology (OJG) , 2013, DOI: 10.4236/ojg.2013.31004
Abstract:

Surrounding rock of coal seam was one of the important factors to gas occurrence. The coal seam gas occurrence was studied by the index of roof strata thickness or sand content rate; we found that there were certain shortcomings. In order to reasonably evaluate the influence of coal seam surrounding rock on gas occurrence in Panji mining area, we quantitatively evaluated the effect of coal seam surrounding rock on gas occurrence by influence coefficient of roof strata thickness, and built six mathematical models of the variational gas content in the mining area which is divided into six gas geological units. The results shows that the coal seam gas content is mainly influenced by 20 mroof strata in each gas geological unit, the gas content presents the tendency of increase, and with the influence coefficient of strata thickness increases, they exist a significant linear relationship.

Unconventional (borehole) Technologies for Gas Fuel Producing from Coal Fields
Vasyuchkov Yu. F.,Vasyuchkov M. Yu
Acta Montanistica Slovaca , 2004,
Abstract: The scheme discribtion of borehole thechnologies for coal fields utilization is cited in the report. The merits and shortages of the technologies are discussed. The several conclusions are expressed.
Using roofs of a seam resonance system to create the model of bump phenomenom - a coal seam in the OKR conditions
Bukovansky Stanislav
Acta Montanistica Slovaca , 1999,
Abstract: Like an ideal model of the bumps rise is possible to create for the OKR saddle layers seams conditions on the base of analyses of oscillation effects resp. drifts using roofs of a seam resonance system - a coal seam at the mountain massif.
RATIONAL DETERMINATION OF SUBLEVEL HEIGHT OF TOP COAL IN STEEP SEAM
急倾斜煤层放顶煤分段高度的合理确定

Wang Weijun,Hou Chaojiong,Xiong Renqin,
王卫军
,侯朝炯,熊仁钦

岩石力学与工程学报 , 2001,
Abstract: The effect of rock pressure on the crack of top coal of steep seam is analyzed by elastic plastic theory. .It is put forward that the top coal of low gaseous steep seam can be caved only when the top coal is in the limiting equilibrium state of stress under the abutment pressure. The sublevel height of top coal is calculated. However, the change of seam thickness has to be thought over when the sublevel height of top coal is determined. Therefore the seam thickness is considered as a random variable, and the reasonable sublevel height of top coal is determined by the reliability.
EXPERIMENTAL STUDY ON THE RELATION BETWEEN THE BURST TENDENCY AND WATER CONTENT IN COAL SEAM
煤层冲击倾向性与含水率关系的试验研究

Mao Xianbiao,Chen Zhanqing,Xu Sipeng,Li Tianzhen,
茅献彪 陈占清 徐思朋
,李天珍

岩石力学与工程学报 , 2001,
Abstract: The relations are determined systematically between the burst tendency and water content, the water content and porosity in coal seam by experiment. It is found that the burst tendency of coal seam depends inversely on the water content, and it is most sensitive in original water content. The saturated water content in coal seam depends on porosity in coal. A reliable quantitative basis is provided for preventing rockburst in coal mine by using water injection method.
Lateral Stress Concentration in Localized Interlayer Rock Stratum and the Impact on Deep Multi-Seam Coal Mining  [PDF]
Mingwei Zhang, Hideki Shimada, Takashi Sasaoka, Kikuo Matsui
International Journal of Geosciences (IJG) , 2013, DOI: 10.4236/ijg.2013.49119
Abstract:

To explore the impact of lateral stress concentration in interlayer rock stratum on the exploitation of protected coal seam, a field experiment was carried out in a multi-seam mining structure. Lateral stress redistribution and interlayer rock failure behavior were surveyed. Then an assistant numerical investigation was implemented to evolve the effect of liberated seam mining and its influence on stress reconstruction in surrounding rock mass. The cause of lateral stress concentration and its impact were discussed finally. Key findings turn out that a certain lateral stress increases in interlayer rock stratum and concentrates on its lower region. Lateral stress concentration and interlayer rock failure are interactional. The former is an inducing factor of the latter; the latter promotes the increase of concentration degree. Extent of lateral stress concentration increases to the maximum as seam distance is about 50 m. But the efficacy of liberated seam mining decreases as the seam spacing gets larger. Protected seam mining is then classified based upon the impact of lateral stress concentration, which helps to prevent the rock burst hazard and then to achieve a reliable mining in deep mines.

Research on Coal Seam Floor Water Inrush Monitoring Based on Perception of IoT Coupled with GIS  [PDF]
Xiangrui Meng, Junhao Wang, Zhaoning Gao
Engineering (ENG) , 2012, DOI: 10.4236/eng.2012.48061
Abstract: To the complication and uncertainty in coal seam floor water-inrush monitoring, Internet of Things (IoT) perception is applied to the monitoring and controlling of coal seam floor water inrush with major impacting factors analyzed, and an open distribution information processing platform is constructed based on IoT-GIS coupling perception. Then using the platform to comprehensively perceive various floor water inrush impacting parameters, an AHP model is established. At this stage, by means of weight reasoning algorithm based on dynamic Bayesian network, the AHP weight can be worked out using the two-way probability transfer and chain rules. Then the multiple factors are spatially fused by GIS to form a non-linear mathematical model for the calculation of the water inrush relative probability index. After that, the discrimination threshold of the comb graph for the floor water inrush relative probability index is used to further identify the floor water inrush mode. The experiments in 10# Coal Seam of Suntuan Mine show that, the accuracy perceived the floor water inrush is above 92%, and the platform of IoT-GIS coupling perception has the obvious technical advantage than traditional monitoring technology. Therefore, it has has demonstrated strong systematic robustness, important theoretical and application significance.
STUDY ON ROCK-BREAKING MECHANISM OF HIGH-PRESSURE PDC BIT WITH DUAL-FLOW CHANNEL
超高压双流道PDC钻头破岩机制研究

WANG Zhiming,SUN Qingde,YU Junquan,WANG Zhenquan,
汪志明
,孙清德,于军泉,王镇全

岩石力学与工程学报 , 2007,
Abstract: The three-dimensional dynamic numerical model of PDC bit to break rock has been set up,in which the finite element models of rock,jet and mechanical tooth are created respectively based on elastoplastic mechanics,hydrodynamics and kinematics of rigid body.The interaction between jet or mechanical tooth and rock is simulated by dynamic contact method.The dynamic boundary is controlled by Hoffman failure rule.The single-step Houbolt algorithm is adopted to solve the dynamic equation.The rock-breaking mechanism has been analyzed comprehensively by various ways such as the interior stress distribution of rock,the weight on bit and torque of bit impacting rock,the volume of rock breaking,the energy of rock breaking,etc..The influences of the number of blade and the position of high-pressure nozzle on bit breaking rock have been studied;and the structure of the dual-flow channel PDC bit has been optimized.
Development and prospect of research on coal-seam gas seepage in the geophysical field
地球物理场中煤岩瓦斯渗流研究现状及展望

PENG Shou-jian,XU Jiang,TAO Yun-qi,CHENG Ming-jun,
彭守建

地球物理学进展 , 2009,
Abstract: Gas seepage in coal-bed is an important aspect of studies on coal and gas outburst. Due to the complex geological environment, inevitably coal seam gas seepage is affected by the geophysical field. Based on the current status of studies on coal seam gas seepage at home and abroad, this paper summarizes the seepage property of coal seam gas affected by the in-situ stress field, geothermal temperature field and geo-electric field as well as coupled flows. Finally it has put forward the further research direction and the development tendency of this field from the view that the experimental study, the theoretical analysis and the project practice proof should be unified.
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