RESEARCH OF THE DYNAMIC AND THE RAIN CHARACTERISTIC OF THE DECOMPOSED GRANITE SOIL SLOPE CALAMITY BY THE LOCAL SEVERE RAIN OF JUNE, 1999 HIROSHIMA PREFECTURE

1)在降雨渗透作用下边坡崩塌机理的试验研究中，利用一个试验边坡，通过改变厚层的存在、密度、地下水类型和降雨强度进行试验。结果表明，具有足够颗粒尺寸的地面不会轻易塌陷，只有地下水具有塌陷的危险。2）在1999年6月的暴雨灾害的“悬崖问卷”研究中，对吴市将有斜坡的住宅区进行了研究，分析和检验了一个悬崖的问卷。在与第一年使用的室内雨水渗透实验相同的模型边坡上，使用风化花岗岩土和河砂进行了各种实验结果表明：25 min后，风化花岗岩土在30 min后产生孔压，河砂分别在5 min和10 min左右达到最大孔压。4）风化花岗岩土的动力特性在固结排水条件下进行了“3-6”扰动饱和三轴压缩试验。5）对风化花岗岩土崩塌边坡的雨灾和地震灾害进行了对比分析。其结果是，暴雨灾害主要集中在陡坡周边的脚口处，地震灾害又发生在城区东西方向的石壁结构崖上，城区内也出现了多处崩塌

1) In experimental research of the slope collapse mechanism by rain osmosis, it experimented by changing the existence of thick layer, density and a groundwater style and rain intensity using an experiment slope. It turns out that the ground with a sufficient particle size cannot collapse easily as a result, and that only groundwater has the danger of collapse.2) The residential area which will have a slope in Kure in research of "the questionnaire of cliff" about a heavy rain calamity in June, 1999 performed, analyzed and examined the questionnaire of a cliff.3) Various experiments were conducted on the same model slope as the indoor rain osmosis experiment used in the first year using the decomposed granite soil and river sand as a result, after 25 minutes, the decomposed granite soil generated pore pressure after 30 minutes and river sand reached after about 5 minutes and 10 minutes respectively at the maximum pore pressure quick.4) The dynamic characteristic of the decomposed granite soil performed the saturation 3 axis compression examination for "3-6 an-disturbed on consolidation drainage condition. The correlation of density and intensity was obtained as a result.5) Comparison examination of the rain calamity and earthquake calamity in the decomposed granite soil collapse slope was carried out. As a result, the rain calamity collapsed focusing on the foot port of the circumference of a steep slope, the earthquake calamity was generated in the direction of east and west of a city area at the cliff of stone wall structure again, and many collapse was seen also in the city area