ŒfÚŽGŽi˜ajF
“ú–{’nkHŠwƒVƒ“ƒ|ƒWƒEƒ€˜_•¶W
VolF
9-3Šª
”NF
1994”N
•ÅF
E.121-E.126•Å
’˜ŽÒi˜ajF
-
ƒ^ƒCƒgƒ‹i˜ajF
-
|
´˜^i˜ajF
-
|
|
ƒL[ƒ[ƒhi˜ajF
-
|
ŒfÚŽGŽi‰pjF
PROCEEDINGS OF THE JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM
’˜ŽÒi‰pjF
Masahiro IIDA, Mario ORDAZ, Hitoshi TANIGUCHI, Carlos GUTIERREZ, Miguel SANTOYO
ƒ^ƒCƒgƒ‹i‰pjF
INTERPRETATION OF WAVE FIELD INSIDE THE MEXICO VALLEY ON THE BASIS OF BOREHOLE DATA
|
´˜^i‰pjF
During the 1985 Michoacan earthquake (Ms=8.1), seismic waves were amazingly amplified in the lakebed zone of Mexico City, which is approximately 400 km from the epicenter, and the long duration of the lakebed seismograms was a real surprise. In the present study, we hypothesize that the long coda is not only surface waves, but also long-period body waves, which are produced by the multipathing due to the long-distance path and the very soft surficial layers. We perform the nonstationary spectrum analysis, the 1-D elastic propagation analysis and the cross correlation analysis for borehole data at lakebed stations. These analyses indicate that the soft surficial layers afford to cause dominant-period waves, and that the long-duration records are composed of both surface waves and long-period body waves.
|
|
ƒL[ƒ[ƒhi‰pjF
-
|
‹LŽ–‹æ•ªF
-
‹æ•ª
@@@ˆÏˆõ‰ï˜_•¶W