| In this paper, upper aquifer Taiyuan formation lithology of Liuqiao NO.1coal mine, Hengyuan coal mine and Wugou coal mine was selected as the research objects. Based on the studied of the geological and hydrogeological conditions, through collected and collated the dates of upper aquifer Taiyuan formation lithology, the development characteristics of Karst fissure, water yield and grouting volume of drill, drilling depth, anomaly area of geophysical prospecting and so on, divided the Karst structure of studied areas. At the same time simulated the diffusion process of grouting in rock mass. Besides, analysed the in-siru test results of floor grouting reinforcement and aquifer reformation in studied area working face. Then builded Karst structure geological models, simulated the grouting diffusion process in it. The research results have a certain guiding role to the follow-up projects in mining area in northern Anhui. Made the following main results and understanding:1. Based on analysed upper aquifer Taiyuan formation lithology and the development characteristics of Karst fissure in studied area, according to floor pore-forming and grouting information, elaborated the relationship between water yield and grouting volume of drilling, as well as the relationship between water yield of drilling, grouting volume of drilling and drilling depth. According to single drilling maximum water yield and unit volume grouting volume of each drilling field, builded four types of Karst structures of upper aquifer Taiyuan formation, such as dissolution pore and pipe net, dissolution fissure and pore net, fracture and dissolution fissure net as well as unitary fracture net, analysed the characteristics of each types and distribution situation in studied area.2. Builded two types numerical models, including homogeneous medium structure and fracture structure, use the COMSOL Multiphysics simulated grouting diffusion effect in rock mass, the results showed that:in the same simulation times, to the homogeneous medium structure, other grouting parameters unchanged, with the porosity of rock and grouting pressure are becoming larger and grouting density is becoming smaller, grouting diffusion distance is gradually increase; to the fracture structure, other grouting parameters unchanged, with the fracture opening, fracture length and grouting pressure are becoming larger and water pressure is becoming smaller, grouting along the fracture diffuses further and further.3. Through developed the in-situ test results of floor grouting reinforcement and aquifer reformation in studied area working face, arranged the dates of grouting pressure in grouting process, gathered orifice pressure of different Karst structure in upper aquifer Taiyuan formation grouting reconstruction, revealed the control effect in Karst structure on the grouting pressure variation with time. According to the dates of grouting connected pores in working face floor, conclusion that grouting diffusion distance is different in different Karst structure, show that the control of Karst structure on grouting diffusion effect.4. Builded Karst structure geological models of upper aquifer Taiyuan formation, simulated the grouting diffusion process, reached the grouting diffusion distance in each types of Karst structures, combined with the field grouting test, diffusion distance in different Karst structure aquifer was got. |
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