Numerical Simulation Research of Flexible Shield Support Lateral Caving Technology

2011 ◽  
Vol 284-286 ◽  
pp. 633-637
Author(s):  
Tong Bin Zhao ◽  
Yan Chun Yin ◽  
Qing Sun ◽  
Shu Dong He

The arrangement and caving order of the mouths after the shield are the key technological problems of lateral caving in flexible shield support face of steep inclined coal seam,and restrict the production.Based on the geological and production conditions of Muchengjian Mining 5113 flexible shield support face in Beijing mining area,lateral caving was simulated by using PFC2D.Single mouth caving and double mouth caving in different orders were researched.It showd that double mouth caving discharged more coal than the single one.When opening two mouths,caving from the upper to the lower had discharged the most coal.Open the third mouth between the two mouths could discharge more coal.The best technology of caving was caving from the upper mouth to the lower one.It increased the rate of recovery and decreased the workload.

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Jie Fang ◽  
Lei Tian ◽  
Yanyan Cai ◽  
Zhiguo Cao ◽  
Jinhao Wen ◽  
...  

The water inrush of a working face is the main hidden danger to the safe mining of underwater coal seams. It is known that the development of water-flowing fractured zones in overlying strata is the basic path which causes water inrushes in working faces. In the engineering background of the underwater mining in the Longkou Mining Area, the analysis model and judgment method of crack propagation were created on the basis of the Mohr–Coulomb criterion. Fish language was used to couple the extension model into the FLAC3d software, in order to simulate the mining process of the underwater coal seam, as well as to analyze the initiation evolutionary characteristics and seepage laws of the fractured zones in the overlying strata during the advancing processes of the working face. The results showed that, during the coal seam mining process, the mining fractured zones which had been caused by the compression-shear and tension-shear were mainly concentrated in the overlying strata of the working face. Also, the open-off cut and mining working face were the key sections of the water inrush in the rock mass. The condition of the water disaster was the formation of a water inrush channel. The possible water inrush channels in underwater coal mining are mainly composed of water-flowing fractured zones which are formed during the excavation processes. The numerical simulation results were validated through the practical engineering of field observations on the height of water-flowing fractured zone, which displayed a favorable adaptability.


2014 ◽  
Vol 945-949 ◽  
pp. 1169-1174
Author(s):  
Xian Tao Zeng ◽  
Ning Wang ◽  
Cong Jiang ◽  
Yun Yi Zhang ◽  
Chang Hai He

In this paper, design of roadway with stope working face Yeqing 8459 had been optimized combined with geological characteristics of the working face based on the actual measurement of ground stress and mechanical properties of coal rock of Yangquhe mine in Feng Feng mining area. Analyzing eight kinds of roadway support design scheme through numerical simulation and evaluating the supporting effect of each supporting design scheme, designating the construction guidelines ultimately.


2021 ◽  
Vol 14 (4) ◽  
Author(s):  
Zhao Chunhu ◽  
Jin Dewu ◽  
Wang Qiangmin ◽  
Wang Hao ◽  
Li Zhixue ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Li Shen ◽  
Qiang Zeng

AbstractIn the present paper, with using diverse methods (including the SEM, the XRD, the TPO, the FTIR, and the TGA) , the authors analysed samples of the major coal seam in Dahuangshan Mining area with different particle sizes and with different heated temperatures (from 50 to 800 °C at regular intervals of 50 °C). The results from SEM and XRD showed that high temperature and high number of pores, fissures, and hierarchical structures in the coal samples could facilitate oxidation reactions and spontaneous combustion. A higher degree of graphitization and much greater number of aromatic microcrystalline structures facilitated spontaneous combustion. The results from TPO showed that the oxygen consumption rate of the coal samples increased exponentially with increasing temperature. The generation rates of different gases indicated that temperatures of 90 °C or 130 °C could accelerate coal oxidation. With increasing temperature, the coal oxidation rate increased, and the release of gaseous products was accelerated. The FTIR results showed that the amount of hydroxide radicals and oxygen-containing functional groups increased with the decline in particle size, indicating that a smaller particle size may facilitate the oxidation reaction and spontaneous combustion of coal. The absorbance and the functional group areas at different particle sizes were consistent with those of the heated coal samples, which decreased as the temperature rose. The results from TGA showed that the characteristic temperature T3 declined with decreasing particle size. After the sample with 0.15–0.18 mm particle size was heated, its carbon content decreased, and its mineral content increased, inhibiting coal oxidation. This result also shows that the activation energy of the heated samples tended to increase at the stage of high-temperature combustion with increasing heating temperature.


2021 ◽  
Vol 1838 (1) ◽  
pp. 012061
Author(s):  
Qihui Zhou ◽  
Zhanjun Huang ◽  
Yong Wu ◽  
Huipeng Zhang ◽  
Yufeng Shi ◽  
...  

2013 ◽  
Vol 295-298 ◽  
pp. 2980-2984
Author(s):  
Xiang Qian Wang ◽  
Da Fa Yin ◽  
Zhao Ning Gao ◽  
Qi Feng Zhao

Based on the geological conditions of 6# coal seam and 8# coal seam in Xieqiao Coal Mine, to determine reasonable entry layout of lower seam in multi-seam mining, alternate internal entry layout, alternate exterior entry layout and overlapping entry layout were put forward and simulated by FLAC3D. Then stress distribution and displacement characteristics of surrounding rock were analyzed in the three ways of entry layout, leading to the conclusion that alternate internal entry layout is a better choice for multi-seam mining, for which makes the entry located in stress reduce zone and reduces the influence of abutment pressure of upper coal seam mining to a certain extent,. And the mining practice of Xieqiao Coal Mine tested the results, which will offer a beneficial reference for entry layout with similar geological conditions in multi-seam mining.


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