Consideration on the Influence of Seismic Shaking on Forest Slope Stability and Landslide Warning Rainfall in the Aftermath of the Strong Earthquake

• 久保田 哲也

  九州大学農学研究院環境農学部門

• Nakamura Go

  Nagase Brothers Inc.

• 篠原 慶規

  九州大学農学研究院環境農学部門

• Aditian Aril

  Laboratory of Erosion Control, Division of Forest Environmental Sciences, Department of Agro–environmental,Graduate School of Bioresource and Bioenvironmental Sciences, Kyushu University

抄録

The research concerning about the warning rainfall criteria of landslides after strong earthquakes is conducted associated with the great earthquake in Eastern Japan in 2011 (M=9.0). After this kind of strong earthquake, soil strength of the slopes in the region that were exposed to the strong seismic forces is generally reduced by seismic shaking (vibration). In this situation, the revised rainfall criteria for landslides are required. On this point of view, the response of landslide to rainfall under this weaken soil condition was studied. Hence, the impact of rainfall events on the specific landslide slopes that experienced the strong seismic shaking is analyzed using numerical simulation method i.e. finite element method (FEM) in order to evaluate the critical rainfall threshold for landslide occurrence. Consequently, we obtained following results. In the result of FEM analysis, the cracks induced by the earthquake are effective to increase the seepage and render the slopes instable. The slope deterioration mentioned above due to the impact of earthquake causes temporarily 40~50% reduction of critical rainfall for landslide occurrence, corresponding to decrease in safety factor “Fs” of the slopes from Fs=1.02~1.04 to Fs=0.83~0.95. This reduction rate of critical rainfall is as same level as in the earlier researches based on field observations.

収録刊行物

• Journal of the Faculty of Agriculture, Kyushu University

  Journal of the Faculty of Agriculture, Kyushu University 59 (1), 163-167, 2014-02-28

  九州大学大学院農学研究院

キーワード

• earthquake
• FEM
• landslides
• rainfall
• slope stability

詳細情報

• CRID: 1390290699661578240
• NII論文ID: 120005411079
• NII書誌ID: AA00247166
• DOI: 10.5109/1434407
• HANDLE: 2324/1434407
• ISSN: 00236152
• 本文言語コード: en
• データソース種別:
  • JaLC
  • IRDB
  • Crossref
  • CiNii Articles