WATER INRUSH MODELLING IN LONGWALL MINING USING ZONE BUDGET METHOD

• Main Author: Arjunoarwan Hatta, Asta
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/51545
• Institution: Institut Teknologi Bandung

When longwall panels are mined, the aquifer layer that may be on top of the panels will fracture, which can cause water inrush into the mining area. Without proper planning, water inrush will pose a danger in the mining area especially when mining production activities are carried out. Groundwater flow modeling into the mining panel area in the study using Zone budget method on Visual ModFlow. Groundwater modeling in this research is divided into three scenarios based on changes in the value of hydraulic conductivity (K) that occur in the fault zone area as far as 30h and 50h (h = thickness of coal) with the area of influence of subsidence, namely 46o (dip-side) and 27o (rise- side). This scenario is a very optimistic, optimistic, and conservative scenario. Total water inrush results for the very optimistic scenario is 169 m3/hour, the optimistic scenario for the 30h and 50h fracture zone is 265 m3/hour and 321 m3/hour respectively, and for the conservative scenario in the 30h and 50h fracture zone is 740 m3/hr and 931 m3/hr respectively. Based on the result of water inrush, it can be concluded that the increase of water inrush is directly proportional to the increase in the value of hydraulic conductivity, the area of the mining panel, and hydrostatic pressure. The impact of mining with the longwall method can eventually cause changes in groundwater flow, the simulation results show that there is a decrease in the groundwater contour on the panel of the mining area about 1-2 meters.