Determination method of water gushing runoff zones in the open pit mining area

摘要

Taking the Hejing limestone mining area of Guangxi Huarun Cement (Pingnan) Company as the research background, the method for water gushing runoff zones of open pit mining area is determined based on numerical simulation and field test. First of all, the calculation model of groundwater movement in open pit mining area is established by the equivalent continuous medium model. Then, calculation parameters of the model are reasonably valued through analyzing the development of karst degree, tracer tests, and pumping tests in drilling holes. Secondly, three existence forms of groundwater seepage field are put forward, and the distribution of groundwater runoff zones is determined by using numerical simulation to analyze the groundwater seepage field influence rules of water accumulation points (such as private mining pit). Thirdly, the results are verified by field tests. The water source and ground water connection in open pit mining area are determined. The results show that (1) the water gushing in the mining area mainly comes from the east and the south. The groundwater flow in the east is uniform, and the most of groundwater is fissure water gushing. (2) The groundwater flow in the south of the mining area is banded, and the most of groundwater is pipe gushing. The results of this research provide a theoretical basis for locating the groundwater runoff zones in karst open pit mining areas.