Abstract:

Abstract: In order to study the law of strata pressure behavior of caving mining in secondary mining area of small pit in thick coal seam and the influence of pillar residue in the upper slice on the working face in the lower slice, we used the finite difference numerical calculation software Flac3D to simulate the distribution rule of stress and energy in Maozequ secondary mining area and we also went to the field to measure the strata pressure. The results show that: pillar residue will put irregular effect on the working face in the lower slice and the range of influence is relevant to the location of pillar residue and the main way of its influence is stress concentration. Besides, the results of numerical simulation are similar with the law which is displayed by strata pressure data. This phenomenon shows that the size of the working resistance has close relationships with anomalous structure in the upper slice. The paper provides a basis for the mine and similar mines working faces to mine safely and efficiently.

Key words: Keywords: the secondary mining area of small pit, sublevel caving, strata behavior, numerical simulation, Flac3D