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)在降雨渗透崩塌机理的试验研究中，利用试验边坡进行了不同厚度、不同密度、不同地下水类型和不同降雨强度的试验研究。结果表明，具有足够粒度的地面不会因此而容易坍塌，只有地下水才有崩塌的危险。2)1999年6月在Kure将会有斜坡的居民区进行了对一次悬崖灾害的问卷调查，并对其进行了分析和检验。3)在与第一年使用的室内雨水渗透实验相同的模型斜坡上进行了各种试验，结果是用分解的花岗岩土壤和河沙，25分钟后，分解花岗岩土在30min后产生孔压，河沙在最大孔压下分别在5min和10min左右达到最大孔压。4)在固结排水条件下，分解花岗岩土的动力特性进行了饱和三轴压缩试验。5)对崩解花岗岩土质崩塌边坡进行了雨害与震害对比检验。结果，雨灾集中在陡坡周边的山脚下坍塌，城东、城西方向的石墙结构崖又发生了地震灾害，城区也出现了多次坍塌。

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