00422494

open access

Version of Record

ヒョウゴケン ナンブ ジシン デ ヘンケイ シタ マンホール ノ カイセキ : ウズガモリ カツダンソウ ゾイ オ レイニ

Analysis of co-seismic deformed manholes in Hyogoken-Nanbu(Kobe) Earthquake : An example of the Uzugamori active fault

Japanese (日本語)

神戸大学都市安全研究センター研究報告

8

347-353

神戸大学都市安全研究センター

2004-03

2007-04-19

The Mj 7.3 Hyogo-ken Nanbu Earthquake hit a Japanese mega-city, Kobe on 17 January, 1995. Although the surface rupture accompanied with this earthquake appeared on the northern Awaji Island, one did not appear obviously in the urban area of Kobe, at which was suffered from the severe damages recorded the 7th degrees of seismic intensity. Some observations and analyses after the earthquake made clear that the earthquake faults moved right-laterally about 30 km in length in the Robe side. On the other hand, some concealed active faults were discovered in the urban area of Kobe according to the various geophysical survey data after the earthquake, for example, the seismic reflection and GPR data. In this study, we discussed the effects of the Uzugamori active fault for the strong ground movement in the urban area of Kobe, based on an analysis of the deformed manholes. The following results were obtained. (1) The deformed manholes in the urban area of Kobe were almost existent on and near the Uzugamori active fault and another sub-parallel concealed (hidden) active fault. (2) Most of them were slipped almost perpendicular to the concealed active faults. It indicates that they were affected amplified seismic wave (directivity) in this area and the faults moved underground at the earthquake. (3) Because the manhole is installed high-densely in a city, and it has a standardized form and the stability of structure, the analysis of co-seismic deformed manholes is very useful in understanding the ground movement during an earthquake in the urban area where the active fault is hidden under the ground surface.

神戸市街地

紀要論文