Effects of Local Characteristics near the Observation Site on the Intensity of Earthquake Ground Motion

Abstract

Japanese seismic intensity is determined based on the earthquake records observed by seismometers of JMA and local governments. Although instrumental seismic intensity expresses properties of the ground shaking wilh a single value, it is too simple to show the various aspects of ground molions. If the seismometer, for example, is installed near a big structure or an edge of the foundation, the response would remarkably be changed due to the vicinity effects. In this study, a collocation of a seismograph is modeled, and the influence to the maximum accelerat ion and seismic intensity are examined by using 2-dimensional FEM analysis. Especially the indices of the earthquake motion were investigated by changing effects of building and geographical conditions.