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Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Geology & Exploration is the property of Xian Research Institute of China Coal Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Mine Automation is the property of Industry & Mine Automation Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The deep mining of coal mines leads to some significant changes in the physical properties of coal and rock, stress environment and gas occurrence law. New disaster features such as stress-driven gas outburst and coal and gas outburst under low gas pressure condition have appeared.In order to guide the prevention and treatment of coal and gas outburst in deep coal mines, the theoretical permeability model of tectonic coal body prone to outburst is established. The coordinated prevention mechanism of pressure-relief and coal and rock properties modification for coal and gas outburst is revealed based on the key structural body theory of coal and gas outburst. The research result shows that the core of prevention and control coal and gas outburst is efficient gas extraction, and the key is to reduce ground stress. This pressure relief has multi-effects of reducing elastic strain energy, improving the coal permeability, promoting gas extraction and reducing the gas internal energy. The prevention and control measures of coal and gas outburst in deep coal mines should be implemented according to two concrete conditions including relieving pressure and reforming coal& rock medium property. In some special areas of coal mines, after adopting the pressure relief measures and implementing gas extraction, other auxiliary measures should be taken to improve the outburst resistance and restrain the gas desorption to ensure mining safety in deep coal mines. [ABSTRACT FROM AUTHOR]

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Sealability of borehole is one of the key foundations of efficient gas drainage. The mechanical properties of coal play important roles in the selection of sealing parameters and the results of borehole sealing. Therefore, this paper aims at understanding the environment of surrounding coal and rock of borehole and analyzing the impacts of coal plastic softening and expansion characteristics on borehole sealing and providing a reliable foundation for the selection of borehole sealing parameters. A linear elastic-plastic stress softening model of “three-fold line” was proposed based on the full stress-strain curve and the mechanical parameters of coal. According to the Linear Mohr-Coulomb Yield Criterion, the radius and displacement of elastic zone, plastic softening zone and plastic flow zone and displacement of the model were calculated. Borehole imaging and data monitoring of gas drainage were conducted. The results show that radial displacement and theoretical sealing radius of surrounding of boreholes was increased by 12. 93 and 2. 60 times compared with the calculated results of Kastner solution. Compared with the adjacent borehole which is unbroken and the sealing parameters are the same, the initial average extraction gas concentration of the borehole decreased by 59%, the average extraction gas concentration decreased by 64. 92% over the same period of 29 d and gas concentration decay rate increased by 3 times. Based on the results, the influence of plastic-softening and dilatancy is one of the main reasons inducing the decrease of initial sealing performance and the decline of gas extraction in late drainage stage. The theoretical permeability radius and grouting pressure for sealing boreholes obtained from Kastner equation was not reasonable. The sealing parameters of boreholes should be selected according to the characteristics of borehole surrounding rock as well. [ABSTRACT FROM AUTHOR]

The deep mining of coal mines leads to some significant changes in the physical properties of coal and rock, stress environment and gas occurrence law. The perturbed range of overlying rock and level of dynamic-static load have also increased significantly. In addition, the disaster effect caused by the linkage of mine groups and the control effect of large geological bodies appear in deep mining. The same disaster effect with the coexistence and conversion of rock burst and coal & gas outburst occurs. Therefore, above characteristics make the prevention and control of dynamic disaster in deep coal mines become a problem to be solved urgently. Considering the situation that the conditions of disaster breeding and mutual transformation mechanism are complex and still unclear, the quick detection method, prevention- control technology and equipment are still lacking, in this paper, the key scientific and technical problems of prevention- control for dynamic disaster in deep mining are condensed, the thought of prevention and control with different sources in multi-scales for coal and rock dynamic disasters in deep mining is proposed, the research direction of prevention and control technology for dynamic disaster in deep mining is determined, and the theory and technical framework of prevention and control with different sources in multi-scales for coal and rock dynamic disasters in deep mining are established. Based on the above achievements, the theory and technology system of prevention and control with different sources in multi-scales for coal and rock dynamic disasters in deep mining are formed successfully, which can provide a theoretical and technical support for the prevention and control of rock burst, the outburst of coal and gas or compound dynamic disaster in deep mining of coal mines in China. [ABSTRACT FROM AUTHOR]