Open AccessStress characteristics and control of coal and rock in steeply dipping coal seam mining under the goaf of a close coal seam group: a case study
Author(s) -
Qiang Fu,
Ke Yang,
Qinjie Liu,
Xiaolou Chi
Publication year - 2020
Publication title -
iop conference series. earth and environmental science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.179
H-Index - 26
eISSN - 1755-1307
pISSN - 1755-1315
DOI - 10.1088/1755-1315/570/5/052017
Subject(s) - coal mining , coal , mining engineering , abutment , deformation (meteorology) , roof , geology , front (military) , problems in coal mining , geotechnical engineering , lagrangian analysis , spall , stress (linguistics) , rock mechanics , engineering , structural engineering , lagrangian , oceanography , physics , mathematical physics , waste management , linguistics , philosophy
Steeply dipping coal seams, which are widespread in western China, are considered to have complex mining conditions. The development of such a seam plays an important role in regional economic development. Some steeply dipping coal seams are distributed at close distances. For closely located coal seam groups, China generally adopts the downward mining method for mining. Aiming at the problems of the appearance of ground pressure such as coal wall spalling and roadway squeezing deformation of a fully inclined working face under a goaf in a close coal seam group, the mining of the 5th and 4th coal at the steeply dipping coal seam in Panbei Mine was established as the engineering background. The mechanical model of the coal zone plastic area in front of the 12124 working face under the goaf and the distribution characteristics of abutment pressure in front of the coal wall were obtained. The working surface layout and coal rock physical and mechanical parameters were derived based on field observation records and indoor rock mechanics experiments. A numerical analysis model based on the fast Lagrangian analysis of Continua 3D software was constructed, and the surrounding rock mechanics during the 12124 working face mining process was simulated. The stress distribution characteristics of the front and back of the 12124 working face under the goaf were obtained, magnitude and location of the stress peak were determined, and superposition mechanism of the support pressure evolution of the fully mechanized thick seam under the goaf was revealed. Through field measurement of the distribution of the working resistance of the supports, the maximum working resistance, position of the supports, and accuracy of the theoretical calculation and numerical simulation were verified within the error range. Furthermore, stability control technology of the surrounding rock of the stope, roof falling, and roadway under this condition was proposed and implemented. Good economic and technical effects were obtained, which ensured safe mining at these working faces.