Estimating dewatering in an underground mine by using a 3D finite element model

• Published in: PloS one 2020-10, Vol.15 (10), p.e0239682
• Main Authors: Hu, Litang, Zhang, Menglin, Yang, Zhengqiu, Fan, Yong, Li, Jixiu, Wang, Hongliang, Lubale, Celestin
• Format: Article
• Language: English
• Subjects: Aquifers; Boreholes; Computer and Information Sciences; Data logging; Dewatering; Earth Sciences; Ecology and Environmental Sciences; Education; Engineering and Technology; Engineering geology; Engineering research; Environmental aspects; Fault lines; Finite element method; Flow pattern; Geological research; Geology; Groundwater; Groundwater flow; Groundwater models; Hydrogeology; Mathematical models; Mines; Mining; Mining accidents & safety; Mining industry; Model accuracy; Observation wells; Occupational safety; Physical Sciences; Precipitation; Pumping; Pumping tests; Rivers; Safety engineering; Subsurface mining; Synclines; Three dimensional models; Underground mines; Water flow; Water inflow; Water levels; Water wells
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0239682

Groundwater inflow to an underground mine will seriously affect its mining plan and engineering geology safety. Groundwater models are powerful tools commonly used in the mines to develop dewatering strategies. Many mines in the Kolwezi area have been present since the 1950s, and groundwater flow patterns have been significantly influenced by mining activities. A mining plan is developed for an underground mine with overturned syncline strata in Kolwezi, Congo. Previous groundwater models using layered homogeneous media lowered model accuracies. A new three-dimensional groundwater model using FEFLOW, consisting of a combined regionally and locally geology models integrating 16 hydrogeological cross-sections and borehole logging data, are formulated to predict the underground dewatering in the study area. A 31-days pumping tests with 3 pumping wells and 28 observation wells are carried out to estimate the hydrogeological properties. The simulated water level data match the observed data rather well. Under 8 scenarios of possible well designs, the model predicts a possible dewatering capacity greater 23,900 m.sup.3 /d at the initial stage of mining. The concept of the model and its application can be a reference for other mines with complex geology for mining safety in the region of interest.