経験的強震動予測におけるいくつかの問題点

The national seismic hazard mapping project of Japan started in 1999. The maps were published in March 2005. This paper describes two problems related to empirical predictions of strong motion that have been posed in the project. One is consideration of the effects of fault geometry in the empirical prediction such as the hanging wall effect. The effects are found significantly in strong motion records of the 2004 Mid-Niigata earthquake (Mw 6.6). Another is the effects of the deviation model of the attenuation relationship on the seismic hazard analysis. The amplitude dependent deviation model seems to provide more reasonable results for earthquakes with a high probability of occurrence. Further discussion of the problems will promise more reliable empirical strong motion predictions

Preliminary Report on the Geotechnical Aspects of the Philippine Earthquake of July 16, 1990

The Philippine earthquake of July 16, 1990 (MS = 7.8), of which epicenter is about 100 km north of Manila city, was one of the most costly single natural disasters in Philippine history. The loss of life of over 1,600 persons resulted. Extensive damage to buildings, roads, embankments, natural slopes, and bridges was observed in a widespread area of approximately 20,000 square kilometers. One of the major causes of the damage was liquefaction of various sandy soils including artificially fills, alluvial deposits of river delta, and sandbars. This paper presents a preliminary overview of damage aspects of the earthquake, with emphasis on liquefaction-induced damage of various structures

Some Problems Related to Empirical Predictions of Strong Motion

The national seismic hazard mapping project of Japan started in 1999. The maps were published in March 2005. This paper describes two problems related to empirical predictions of strong motion that have been posed in the project. One is consideration of the effects of fault geometry in the empirical prediction such as the hanging wall effect. The effects are found significantly in strong motion records of the 2004 Mid-Niigata earthquake (Mw 6.6). Another is the effects of the deviation model of the attenuation relationship on the seismic hazard analysis. The amplitude dependent deviation model seems to provide more reasonable results for earthquakes with a high probability of occurrence. Further discussion of the problems will promise more reliable empirical strong motion predictions