
Optimization of staggered distance of coal pillars in multiseam mining: Theoretical analysis and numerical simulation
Author(s) -
Sun Xueyang,
Lu Mingjiao,
Li Cheng
Publication year - 2021
Publication title -
energy science and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.638
H-Index - 29
ISSN - 2050-0505
DOI - 10.1002/ese3.824
Subject(s) - coal mining , reduction (mathematics) , slip (aerodynamics) , computer simulation , line (geometry) , subsidence , mathematics , coal , mining engineering , geotechnical engineering , geology , computer science , geometry , engineering , statistics , paleontology , structural basin , aerospace engineering , waste management
Aimed at solving problems related to water retention and loss reduction in multiseam mining, a mechanical model of staggered distance mining was established. First, elastic and plastic slip line field theories were used to calculate the reasonable staggered distance expressions of multiseam mining. The staggered distance schemes of multiseam mining were optimized using the numerical simulation software FLAC3D. By performing an experiment comparing similar materials, the influence on water retention and loss reduction by optimal and unfavorable staggered distance schemes in multiseam mining was explored. The results showed that the σ zz curve was distributed in the shape of a “peak” of the staggering distance coal pillars, the Z displacement curve was a “Л,” and the surface subsidence curve was a “W.” Each of these displayed the rule of “decrease then increase.” In staggered distance multiseam mining, the optimal staggered distance value for coal seam Nos. 2 and 3 was 40 m, while the most unfavorable staggered distance value was 0 m. The corresponding subsidence coefficients of the optimal staggered distance values were 0.29, 0.23, and 0.19, under the condition of keeping the optimal staggered distance value for coal seam Nos. 1 and 2 unchanged. These results could be beneficial in reduction of surface subsidence and may also have specific practical engineering significance.