Application of Microgravity Survey for Imaging the Density Distribution of the Rock Fill Dam Itself

P354 APPLICATION OF MICROGRAVITY SURVEY FOR IMAGING THE DENSITY DISTRIBUTION OF THE ROCK FILL DAM ITSELF Summary 1 Microgravity survey was performed at a rock fill dam in order to image the density distribution. The terrain effect was precisely calculated by applying modified triangular element method with arbitrary shaped polyhedra. The influence of a lake nearby and the edge of dam were also taken into consideration. The dam was modeled as cells of arbitrary shaped polyhedra based on the blueprint of the dam. Adaptive simulated annealing (ASA) method was applied as 3-D gravity inversion. Inverted density sections clearly distinguished the