Perpustakaan Digital ITB

Highly fractured rocks in Grasberg open pit and surrounding of PT Freeport Indonesia (PTFI) result in fractured groundwater flow media. It is due to the complex geological structure and lithological condition. Accordingly, it leads to anisotropic distribution of hydraulic conductivity. The paper will be devoted tothe modeling of two dimensional (2D) spatial distribution of hydraulic conductivity using neural network. Surface fracture mapping database will be used to estimate 2D equivalent anisotropic hydraulic conductivity tensor based on the Oda et al (1996) approach. Modeled anisotropic hydraulic conductivity is then checked at some points where the slug tests for isotropic conductivity are observed. Co-relation, validation and training between modeled and observed hydraulic conductivity is then carried out using transformation of vector anisotropic hydraulic conductivity into the scalar isotropic hydraulic conductivity. Following training step, neural network will then generate two dimensional model of anisotropic hydraulic conductivity distribution. It is beneficial for modeling of shallow anisotropic flow of groundwater distribution.