短-长壁工作面充填无煤柱开采方法研究

To decrease the loss of panel-separated pillars in coal mining and improve the gob-side roadway stability of pillarless coal mining, an interval short-and long-walls backfilling pillarless coal mining method has been proposed. Firstly, the short-wall longwall panel and the long-wall longwall are arranged at intervals along the main transport roadway. The short-wall panel is equivalent to the panel-separated pillars in the traditional fully mechanized mining. Then, the short-wall is mined using strip backfilling mining method. The coal strip pillars can be parallel or vertical to the length direction of the short-wall panel according to the difference of working face width. The backfilling strips gradually replace coal strip pillars, and form a wide backfilling body which isolates the adjacent longwall panels and supports the overlying strata. Finally, a start-up room is excavated to form a longwall panel when the two adjacent short-wall panels have been mined. The layout of the long-wall panel is consistent with the conventional fully-mechanized mining. The key technique is the stability of strip or backfilling pillars. Therefore, the theoretical calculation formula of mining strip width is deduced according to beam type and plate type fracture models. Meanwhile, the theoretical calculation formula of coal/backfill strip pillar width is deduced based on the Wilson Theory. Feasibility analysis shows that the optimization of coal mining and backfilling sequences can realize the separation of coal cutting and backfilling process, ensuring safe production and improve efficiency. Compared with traditional pillarless coal mining methods, such as in-situ roadway backfilling retaining along goaf and presenting backfilling body along wide roadway wall, there are solid coal or backfilling bodies on both sides of the mined-out strip in the short-wall panel; Therefore, there is no need to build large scale building formwork or wall before mined-out strip backfilling, which means high quality roof-contacted and low safety risk, and high efficiency. The interval short-and long-walls backfilling pillarless coal mining technology can increase the economic benefits of coal mine. Besides, underground storages can be constructed simultaneously during the backfilling mining process of longwall panel to store natural gas, CO₂, and compressed air with internal energy or water with potential energy.