关键词: UDEC, 数值模拟, 分层开采, 覆岩运动, 岩性识别

Abstract: In the layered mining of coal mine working faces，the overlying rock structure and stress field formed by the mining-induced subsidence of the upper working face will have a significant impact on the mining of the lower working face.To ensure the safe mining of the lower working face，based on the 2- 1 section 2109 working face of Jining Coal Mine，this study uses methods such as drilling observation，nat⁃ ural gamma（GR）rock type identification，and UDEC numerical simulation to analyze and study the rock layer structure of the layered mining working face，the fragmentation of the goaf area，and the movement of the overlying rock caused by the excavation of the working face.The research results show that the overly ⁃ ing rock layer of the 2#coal is a mutual layer structure of sandy mudstone and mudstone，which is prone to collapse and is beneficial for the mining of the lower working face.After the upper working face is mined， the roof collapses relatively fully，but the cementation degree is poor.After the upper layer mining，there is a stress concentration situation in the lower coal body below the remaining coal pillar.When the lower working face cuts through the coal pillar influence area，the stress concentration area shifts towards the edge of the goaf，which is likely to aggravate the risk of coal wall spalling and end face collapse.The study reveals the interrelationship between the movement of the overlying rock and the stress distribution under the condition of layered mining of thick coal seams，and proposes that for the lower working face mining under such conditions，the stability of the false roof and the influence of the coal pillar stress should be giv ⁃ en special attention，providing a reference for the safe mining of the lower working face under similar con ⁃ditions.

Key words: UDEC numerical simulation, layered mining, overlying rock movement, lithology identi? fication