Velocity and Absorption Analysis from Tomographic Sonic Experiments on Ancient Stone Piers

N-32 VELOCITY AND ABSORPTION ANALYSIS FROM TOMOGRAPHIC SONIC EXPERIMENTS ON ANCIENT STONE PIERS L. ZANZI 1 E. CARDARELLI 2 and M. LUALDI 1 Abstract 1 Traveltime and spectrum centroid have been backprojected to extract from sonic experiments on ancient stone piers the distribution of velocity and absorption. A feasibility study was necessary to ensure the applicability and the reliability of the absorption results derived from the frequency downshift analysis. The case study consists of 28 tomographic sections executed on 8 massive stone piers of a 17 th century church where a very intensive investigation program was planned to assess the