关键词: 深埋煤田区, 七里镇砂岩, 首采工作面, 涌水量, 相邻矿井

Abstract: Hujierte mining area in the border area between Mongolia and Shaanxi is a new developing coal base, which has some problems, such as unclear hydrogeological conditions and frequent water damage problems. By analyzing the geological and hydrogeological characteristics of the roof of the first mining face of four mines in hujierte mining area, and the change and difference of water inflow during mining, we hoped to find out the hydrogeological conditions under the disturbance in the initial stage of coal mining in this mining area. It provided a scientific basis for water disaster prevention and control in Inner Mongolia and Shaanxi mining areas. The results showed that under the control of sedimentary cycle, and the action of river rejuvenation in the early Zhiluo formation, a relatively strong erosion was formed on the Yan'an formation, forming a regional aquifer with strong water abundance (i.e. qilizhen sandstone), which was the main water filled aquifer in the first mining coal seam. Muduchaideng and the south of Menkeqing were located in the middle of guzhiluo river. The lithology was mainly medium and coarse-grained sandstone and conglomerate. The riverbed width was large. It cutted deeply into Yan'an formation. The aquifer thickness was generally greater than 40m. The initial water inflow of underground boreholes was generally greater than 100m3/h, and the initial water pressure was as high as 6.0MPa. Generally, it was characterized by strong water yield and high confined water pressure. Hulusu, Bayangaole and the north of menkeqing were located on banks of the ancient riverbed of Zhiluo river. The aquifer thickness was generally 20~30m, and the initial water inflow of underground boreholes was basically less than 30m3/h. The water inflow of the first working face of the four mines gradually increased with the mining of the working face. The maximum water inflow of the first working face of Hulusu and Bayangaole mines were 645.0m3/h and 494.0m3/h respectively, and there were water abundance differences in different areas of the sandstone aquifer in Qilizhen, resulting in a stepped increase in water inflow with great fluctuation, It was consistent with the characteristics of thin sandstone aquifer and weak water yield in Qili town. The maximum water inflow of the first mining face of menkeqing and Mudu Chaideng mines were 1372.0m3/h and 938.0m3/h respectively, and the overall water yield of the sandstone aquifer in Qili town was strong and uniform. The increase of water inflow showed a steady increase trend with small fluctuation, which was consistent with the characteristics of large thickness and strong water yield of the sandstone aquifer in Qili town on the roof of this area.