22 research outputs found
SURVEY ON UNDERGROUND SOIL STRUCTURE OF THE FUKUI PLAIN THROUGH MICROTREMOR AND GRAVITY OBSERVATIONS
P wave Velocity and Damping Structure of KIK-net Observation Sites in Fukui Prefecture
By using a divided soil model, P wave velocity and damping structures of KiK-net observation sites in Fukui Prefecture, were examined by optimizing the observed seismic vertical transfer function, through the genetic algorithm. As a result, P wave soil velocity models with P wave damping coefficients were proposed. The obtained empirical relationship of the internal damping coefficients of the sites is as follows. The value of internal damping coefficient is about 59, in case of the P wave velocity being less than 1700m/s, and is 117 in other case. Moreover, it is said that P wave damping factor has as about twice value as the S wave ones up to 10%