Mechanical Analysis of Weakly Cemented Roof of Gob-side Entry Retaining in Fully-Mechanized Top Coal Caving Mining
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To investigate the mine pressure behavior of weakly cemented roof of gob-side entry retaining (GER) in fully-mechanized top coal caving mining, the structural characteristics of lateral immediate roof in 4-1101 working face of Awuzisu Coal Mine were studied by using of numerical simulation, theoretical analysis and in-site measurement. Mechanical model of “equivalent block” composite structure of immediate roof was established, and verified by field test. The results indicate that weakly cemented roof has a large caving range, and it is easy to form the “equivalent block” composite structure in mechanized top caving mining. This structure affects roof breaking, and provide vertical constraint to the roof of GER. It explains the phenomenon that, the roof pressure of GER increases with the advancing of the working face, but the growth rate decreases gradually before the main roof breaking. This research can provide reference to roadside support design and surrounding rock control of GER with weakly cemented roof.
KeywordsWeakly cemented Fully-mechanized top coal caving mining Gob-side entry retaining Immediate roof Equivalent block structure
The research described in this study was financially supported by National Key R&D Program of China (2018YFC0604703), National Natural Science Foundation of China (Ning J.G. No. 51574154, and Tan Y.L. No. 51874190), and the Tai’shan Scholar Engineering Construction Fund of Shandong Province of China (Tan Y.L. No. ts 201511026).
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