Abstract
This paper describes a foundation work for reducing the earthquake response, of structures founded on firm rock. A high damping material is laid in the clearance between the basemat and the underlying rock, thus giving a higher damping factor to the structure and reducing its earthquake response. The effectiveness of this foundation work was examined analytically with changing the damping factor and the thickness of the material used in this foundation work. In order to develop the high damping material, the material tests were performed for the mixture material of gravel and asphalt.