掲載雑誌（和）： 日本地震工学シンポジウム論文集 Vol： 9-1巻 年： 1994年 頁： 787-792頁 著者（和）： 風岡　修，　楡井　久，　楠田　隆，　香村　一夫 タイトル（和）： 火山砕屑物の液状化特性　−北海道駒ヶ岳クルミ坂岩屑なだれ堆積物を中心に− 抄録（和）：
- キーワード（和）： - 掲載雑誌（英）： PROCEEDINGS OF THE JAPAN EARTHQUAKE ENGINEERING SYMPOSIUM 著者（英）： Osamu KAZAOKA, Hisashi NIREI, Takashi KUSUDA, Kazuo KAMURA タイトル（英）： LIQUEFACTION RESISTANCE OF VOLCANICLASTICS - EXAMPLE OF KURUMIZAKA DEBRIS AVALANCHE DEPOSIT FROM KOMAGATAKE VOLCANO, HOKKAIDO, NORTHERN JAPAN - 抄録（英）：
The Southwest off Hokkaido earthquake, magnitude 7.8 on the Richter scale, occurred at 22:17 (J.S.T.). July 12, 1993, near Okushiri island in the Japan sea. Many damages, land subsidence, land depression and jetted ash, were caused by liquefaction-fluidization at the earthquake around Akaigawa area in Mori Town and Onuma lake in Nanae Town on the foot of Komagatake Volcano, Hokkaido. All core samples were taken by core sampler at a pension, Morinonakano Chiisanaie, in Akaigawa area, Mori Town (Fig. 1). Many ash volcanoes were observed at the pension, which was damaged by lliquefaction-fluidization-induced land subsidence. Kurumizaka debris avalanche deposit (Kr), consisted mostly of clay to boulder size fragments (Fig. 3) of andesite from Komagatake Volcano, is distributed in damaged part. Dark brown silty sand bed(Ds) (Fig. 4) was thickly distributed in non-damaged part. Ground water head was about 1m of depth. And matrix of Kr is injected in Ds (Fig.2). Therefore the above phenomena show that Kr liquidized and fluidized at earthquake. Standard penetration test blow counts are dispersive, 24 to over 50, on Kr, because of including low content, 20 to 40%, of granule to boulder angular gravels. Kr is matrix supported volcaniclastic gravelly ash bed (Fig. 5). Accordingly the strength of the bed is put under the control of the strength of the matrix part of the bed. Matrix part of the bed have low dry density, 1.72 to 1.76 g/cm3, but low void ratio, 0.548 to 0.588, because of matrix mud rich (Fig. 6) . The results of the cyclic undrained triaxal tests on disturbed samples show that the liquefaction resistances of the volcaniclastics, the matrix of the Kr and the April 1992 Unzen air fall ash, are lower than those of normal sediments (Fig7, 8). Because the liquefaction resistance of the matrix mud of Kr is low. Then cohesion of the matrix mud of Kr without clay minerals (Fig. 9) is lower than matrix mud of normal sediment. キーワード（英）： - 記事区分： - 区分 　　　委員会論文集