POST-EARTHQUAKE ESTIMATION OF SITE-SPECIFIC STRONG GROUNDMOTION

摘要

In the days, months, and sometimes years following a significant earthquake, there is often a need for anestimate of the strong ground motion that is likely to have occurred at a given site. A common example ofthe use of these estimates is for assessing damage that may not be readily observed by site inspection orthat may have been partially or completely repaired during the period between the earthquake and thepresent time. When the site is located at or very close to a free field ground motion recording station, theproblem is easily solved, as the ground motion at the site can be assumed to be that of the recordingstation. However, when the site is located relatively far from the a ground motion recording station (e.g.,greater than 1 km), or when there are two or more recording stations that are located in the vicinity of thesite, the problem is not so easily solved. Additional complications are introduced when the site conditionsat the site and the recording station(s) are different, and when the ground motion propagation path is notthe same between the seismic source and the site and between the seismic source and the recordingstation(s). This paper presents a method for the post-earthquake estimation of site-specific strong groundmotion. Also included is a method for quantifying the level of confidence associated with the groundmotion estimate. An illustrative example is included.