Abstract Gobs and coal pillars left in the upper coal seam exploitation bring a series of changes to the surrounding rock structures and stress environment of the roadway in the lower coal seams, which leads to difficulties in roadway maintenance. Firstly, the deformation and failure laws of roadway surrounding rock during shallow-buried multi-seam mining are studied using UDEC simulation. The results show that the vertical-stress concentration of the roadway under the coal pillar is stronger than that under the gobs and solid coal. The roadway displacement mainly undergoes three stages, i.e. severe deformation, slow deformation and deformation stabilization. Each of the three stages has the critical deformation value. The roadway displacement under the coal pillar also is larger than that under the gobs and solid coal. Then, allowing for its location, the roadway can be divided into three subareas, including below solid coal, below gobs and below coal pillars. The roadway below gobs consist of two kinds of subareas, i.e. the interlayer spacing is 3.2–4 m and the other is larger than 4 m. The support schemes corresponding to the four subareas are put forward. Finally, these proposed support schemes are used in the subareas of No. 20314 auxiliary haulage roadway. The field monitoring results show that the roadway displacement is small and bolt (cable) forces are stable, and the support effect is excellent. This study can provide a reference for roadway support in shallow-buried coal seams under similar geological conditions.

中文翻译：

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浅埋多煤层开采巷道围岩变形破坏规律及支护优化

摘要 上煤层开采遗留的空洞和煤柱，给下煤层巷道的围岩结构和应力环境带来一系列变化，给巷道维护带来困难。首先，利用UDEC模拟研究浅埋多煤层开采巷道围岩变形破坏规律。结果表明，煤柱下巷道竖向应力集中强于采空区和实煤下巷道。巷道位移主要经历剧烈变形、缓慢变形和变形稳定三个阶段。三个阶段中的每一个阶段都有临界变形值。煤柱下的巷道位移也大于采空区和固体煤下的巷道位移。然后，考虑到其位置，该巷道可划分为三个分区，包括固体煤以下、采空区以下和煤柱以下。采空区下巷道由两种分区组成，即层间距为3.2～4​​ m，另一种大于4 m。提出了四个分区对应的支持方案。最后，将这些建议的支护方案用于20314号辅助运输巷道分区。现场监测结果表明，巷道位移小，锚杆（索）受力稳定，支护效果优良。该研究可为类似地质条件下浅埋煤层巷道支护提供参考。采空区下巷道由两种分区组成，即层间距为3.2～4​​ m，另一种大于4 m。提出了四个分区对应的支持方案。最后，将这些建议的支护方案用于20314号辅助运输巷道分区。现场监测结果表明，巷道位移小，锚杆（索）受力稳定，支护效果优良。该研究可为类似地质条件下浅埋煤层巷道支护提供参考。采空区下巷道由两种分区组成，即层间距为3.2～4​​ m，另一种大于4 m。提出了四个分区对应的支持方案。最后，这些建议的支护方案用于20314号辅助运输巷道分区。现场监测结果表明，巷道位移小，锚杆（索）受力稳定，支护效果优良。该研究可为类似地质条件下浅埋煤层巷道支护提供参考。现场监测结果表明，巷道位移小，锚杆（索）受力稳定，支护效果优良。该研究可为类似地质条件下浅埋煤层巷道支护提供参考。现场监测结果表明，巷道位移小，锚杆（索）受力稳定，支护效果优良。该研究可为类似地质条件下浅埋煤层巷道支护提供参考。