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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 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 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 Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology 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 Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office 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 Chinese Journal of Applied Ecology / Yingyong Shengtai Xuebao is the property of Chinese Journal of Applied Ecology 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.)

In order to study failure characteristics of coal seam floor in deep confined water, this paper established the fluid solid coupling numerical model to analyze the failure characteristics of coal seam floor in the mining process of the working face based on the engineering background of the 3501 working face of No. 2 well in the coal mine of Liang Baosi Coal Mining Group by using the FLAC3D numerical simulation software. The results of studies show that after mining in the coal seam floor, confined water conductivity significantly increased and eventually reached a peak of 19 m. The failure depth of coal seam floor first increased and then leveled off. When the working face advanced to 120 m, it reached a maximum of 18 m. Through the theoretical calculation and the further validation of field measurement, the simulation results are close to the theoretical calculation and field measured value. Thus the FLAC3D numerical simulation software can be used in the study of failure characteristics of coal seam floor in deep confined water. [ABSTRACT FROM AUTHOR]

In order to study the sensibility of coal seam floor damage depth from the main factors of the inclined coal seam floor，based on the semi infinite body theory in elastic mechanics，a mechanical model was established to model the floor damage depth along the inclined direction of coal seam，and the maximum floor mining damaged depth of inclined coal seam was calculated. Under the project background of stope conditions of Yangcheng Coal Mine，based on the FLAC3D numerical simulation software，and in the way of orthogonal test，a numerical simulation was made to simulate the characteristics of coal seam floor damage in 3306 working face. Furthermore，this paper made a calculation to the simulated result in the way of matrix analysis and variance components method to identify the sensibility of each factor influencing the depth of coal seam floor damage. Research shows:① with the increase of the propulsive distance of working face，the minimum principal stress value of the floor is more similar to the confined water pressure value，and the equal areas between the minimum horizontal principal stress value and floor confined water pressure value are in continuous expansion and the danger of floor water inrush increases；② the order of each factor that influences floor damage depth as follows: stope width，mining depth，cohesive force，mining thick，coal seam dip angle，hydraulic pressure，and internal friction angle. And the variance analysis results show that the order of sensibility of each factor that influences floor damage depth as follows:the apparent factors are stope width，mining depth，and cohesive force. However，the unapparent factors are mining thick，coal seam dip angle，hydraulic pressure，and internal friction angle；③ the optimal scheme of orthogonal simulation experiment test is determined by matrix analysis method，which can effectively reduce the danger of floor water inrush with the minimum floor failure depth. [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.)

In terms of the technical problems of mining above confined water and under building, on the basis of the systematic analysis on the properties of fly ash high-water material, filling process and “tunnel type coal mining” which is in the prohibited equipment and technology directory in underground coal mining,through theoretical analysis, indoor experiments and field experiment and so on, a fly ash high-water shortwall part filling panel design and related control technologies were studied systematically. The main study topics and conclusions are summarized as follows:① The foaming mechanism of fly ash high-water filling material, properties, filling processes were analyzed;② A shortwall part filling panel design method and mining-filling program and techniques were put forward.The numerical simulations demonstrated that the floor plastic zone was 6-8 m and the roof plastic zone was 10-12 m based on the joint support system of 50 m filling body and 20 m goaf;③ The filling body density,in situ strength and safety coefficient were showed that the top ratio of the filing body and roof was more than 95%, the in-situ strength was 1.93 MPa, the safety coefficient was 6.8, and the joint support system of fly ash high water filling body could be maintained stable;④ The filling body and floor deformation monitoring showed that the roof maximum subsidence was 80 mm, the floor maximum damage depth was 8 m, and the confining bed thickness of the floor was within the safety limit. The study was carried out at No.9111 coal face in Bucun Coal Mine. The relevant research findings could have some referential significance and application value in similar mining conditions. [ABSTRACT FROM AUTHOR]

In order to study the influencing factors on the failure depth of floor，with the consideration of the inclined length of working face，mining thickness，mining depth，rock mechanical parameters and different water pressure，the FLAC3D was used to simulate the failure depth，and the orthogonal experiment method was used to analyze the simulation results in this study. In addition，the sensitivity of influencing factors was investigated. The results show that the sensitivity sequence of influencing factors is as follows: the inclined length of working face，mining depth，and mining thickness. Tensile strength has a significant influence on the depth of tensile failure，while the sensitivity of cohesive force and internal friction angle have no significant effect on the failure depth and the tensile failure depth. The effect of the sensitivity of tensile strength，internal friction angle on the shear failure depth is weak. The cohesive force has a significant influence on the shear failure depth. With the increase of confined water pressure，the minimum principal horizontal stress is very close to the confined water pressure，and has an increased scope，which show the risk of water inrush increases. [ABSTRACT FROM AUTHOR]