著者

奥西 一夫 諏訪 浩

出版者

日本自然災害学会

雑誌

自然災害科学 (ISSN:02866021)

巻号頁・発行日

vol.11, no.1, pp.27-37, 1992-04-30

被引用文献数

2

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A landslide at a site beside the prefectural road connecting Otsu and Shigaraki, Shiga Prefecture, Japan resulted in the death of two persons. According to a post-disaster inspection, the landslide involved a translational sliding of a V-shaped block, toppling and fall. These movements are thought to have been controlled by the joint system in the granite which composed the slope. A dynamical analysis of the destruction of steel pillars which had supported the protective fence reveals the velocity of debris and suggests the mechanism of the slope failure. Discussion covers the predictability of such roadside hazards and the possible countermeasures. Considering a wide variation in the mode of roadside slope failures, importance of studies of the causes for individual cases is emphasized in conclusion.

著者

平野 昌繁 諏訪 浩 藤田 崇 奥西 一夫 石井 孝行

出版者

京都大学防災研究所

雑誌

京都大学防災研究所年報. B = Disaster Prevention Research Institute Annuals. B (ISSN:0386412X)

巻号頁・発行日

vol.33, no.B-1, pp.219-236, 1990-04-01

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Toppled rock blocks from the steep cliff along the Echizen Coast, Fukui Prefecture, hit apart of the shelter (rock-shed) below, and 15 persons in a micro-bus just passing there were killedby the breakage of the shelter on July 16th, 1989. The rock falls foregoing the toppling at leastfor one hour were reported by two eye-witnesses who had watched the full-process of the rock wallcollapse. Their statements give cleary the mode of the collapse starting with the tilting (toppl-ing) of a part of the joint block composing the partly over-hanged sea cliff. The joint block tiltedabout 30 degrees was then disintegrated, falling vertically on the earth surface. Distribution ofthe scattered blocks after the fall suggests the rotation of the blocks around an inclined axis atthe base of the cliff. The rotation is also confirmed by the fabric analysis of the distributed blocks.A part of the disintegrated blocks hit the rock-shed roof at its edge. Intensity of the impactforce given to the soil-covered roof is estimated to be 1100 ton-force, assuming the volume andsize of the individual block deduced from the survey after the fall.

著者

土石流研究グループ 奥西 一夫 横山 康二 諏訪 浩 矢野 勝正 大同 淳之 奥村 武信 中島 暢太郎 枝川 尚資

出版者

京都大学防災研究所

雑誌

京都大学防災研究所年報 (ISSN:0386412X)

巻号頁・発行日

no.14, pp.691-705, 1971-09

被引用文献数

1

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A new observation system for rocky mudflow was designed by the Mudflow Research Group.The system consists of a detector on mudliow arrival and automatic switch circuit for VTR, 35mmcamera and firing of flare tube in order to record the state of moving mudflow. In addition to thissystem, rain gauges and water level recorder are necessary for the survey of hydrological characterin a small mountaineous basin. During last summer in 1970, the observation system and hydrolo-gical survey instruments had been set along Kamikamihori valley at eastern slope of Mt. Yake andtested in regard to the practical effectiveness. The front velocity (1-5 m/see) of mudflow wasmeasured correctly from the record obtained by the new system.