SEISMIC RISK ESTIMATION CONSIDERING THE UNCERTAINTY OF FAULT PARAMETERS FOR NEAR FIELD EARTHQUAKES

摘要

Near field earthquakes bring catastrophic disasters on large urbanized cities. Local governments must prepare the regional mitigation plans on the basis of seismic hazard and risk estimation in order to protect the building environment and the population. In case of Sapporo City, that is our research target, it is difficult to specify the source parameters of near field earthquakes affected the populated area. It is necessary to investigate the influence of indefinite parameters upon the risk assessment. In this paper, we enforce an importance of the plural estimation of seismic damages by probable earthquakes occurring near the urban area. Paying attention to the difficulties of taking measures against all of the cases on estimated damages, we give an example of the rule of making decision about the priority of mitigation plans from the point of view of earthquake engineering and political science.