学会誌「自然災害科学」

自然災害科学53 Vol.19,No.2, 2000

【報告】[Scientific Report]

1999年6月末集中豪雨による山口県下の斜面災害

Slope Disasters during the 1999 Local Severe Rainfalls in Yamaguchi Prefecture

山本 哲郎*・鈴木 素之*・宮内 俊彦**・原田 博***

Tetsuro YAMAMOTO*, Motoyuki SUZUKI* Toshihiko MIYAUCHI** and Hiroshi HARADA***

Abstract

In Yamaguchi prefecture two natural disasters caused by heavy rainfalls occurred between the 25th and 27th, and on the 29th of June, 1999, respectively. The authors investigated the slopes that failed in these two disasters from geological and geotechnical viewpoints and examined some physical properties of the surface soils of the failed slopes. It was found in the latter disaster that the slopes failed intensively in the region having more than 200 mm of accumulated rainfall. It was also clarified that the dimensions of the slope failure in both disasters were comparatively small, and many slopes supported by countermeasures which had been damaged by past heavy rainfalls failed again. The surface soils were widely classified in the range of cohesive soil to silt with gravel, and their physical properties differed considerably according to the degree of weathering irrespective of the kind of constitutive rock.

キーワード:

山口県，集中豪雨，斜面崩壊，表層土，物理的性質，対策工

Key words:

Yamaguchi prefecture, heavy rainfall, slope failure, surface soil, physical property, countermeasure
*
山口大学工学部
Faculty of Engineering, Yamaguchi University
**
山口大学大学院理工学研究科博士前期課程
Graduate School of Science and Engineering, Yamaguchi University
***
日特建設(株)
Nittoc Construction Co., Ltd.