Perpustakaan Digital ITB

Drain hole has an important role to reduce groundwater table on a slope of coalopen pit mine. Groundwater condition on acoal open pit mine slope with a homogeneous groundwater flow media is highly dependent on the type of lithology and the groundwater bearing-rocks. The drain hole on acoal open pit mine slope is very influential on the water discharge and the length of the drain hole. This paper presents a discussion on the effect of drain holeinstallation with an inclination angle of 65o and 90o on the discharge and drain hole length. The results show that the drain hole with an angle of 65oresults in greater groundwater discharge than the 90o angle. In addition, the drain hole with inclination angle of 65o is shorter than that of the drain holeinstalled with an inclination angle of 90o, thus reducing the operating costs of the open pit mine slope drainages.