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)在雨渗透作用下坡面崩塌机理的试验研究中，以试验坡面为研究对象，通过改变坡面厚层的存在、密度、地下水类型和降雨强度进行试验。结果表明，具有足够粒度的地面不容易塌陷，只有地下水才有塌陷的危险。(2) 1999年6月暴雨灾害“悬崖调查问卷”调查中，对库里市将有边坡的居民区进行了悬崖调查问卷的编制、分析和检验。3)在同一模型坡上进行了与第一年室内雨渗透实验相同的各种实验，结果表明，在25分钟后，分解的花岗岩土和河砂在30分钟后产生孔压，河砂在5分钟左右和10分钟后分别达到最大孔压。4)在固结排水条件下，对分解后花岗岩土的动力特性进行了“3-6扰动”饱和3轴压缩试验。得到了密度与强度的相关关系。5)对分解后的花岗岩土崩落边坡的雨灾与地震灾害进行了对比研究。结果，暴雨灾害主要发生在陡坡周缘的脚口，地震灾害主要发生在城东、城西方向的石壁结构悬崖处，城西地区也发生了多次地震灾害

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