Rainfall and Its Infiltration Conditions for Landslide Occurred at Edge of Pyroclastic Flow Plateau in the Kyushu Island, Southwestern Japan
Rainfall and Its Infiltration Conditions for Landslide Occurred at Edge of Pyroclastic Flow Plateau in the Kyushu Island, Southwestern Japan
复制标题
日本西南部九州岛火山碎屑流高原边缘滑坡的降雨及其入渗条件
DOI：
10.1007/978-3-031-25042-2_16
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Sueda Yuki
中科院分区：
文献类型：
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作者：
Ohta Takehiro;Yamashita Jumpei;Sueda Yuki
2012年7月的暴雨在阿索火山碎屑流高原边缘造成了许多滑坡，包括日本九州岛的阿索-3和阿索-4火山碎屑流沉积。这些滑坡可分为两种类型：发生在阿索-4区的盖层型滑坡和发生在阿索-3区的雨水直接入渗型滑坡。两种类型的滑坡滑动面均位于火山碎屑流存款的下部火山碎屑下落层。最大小时降水量和有效降水量的半衰期为1.5小时控制滑坡的发生和不同的滑坡易发区和非易发区之间的盖层和直接渗透类型。这些参数是较大的滑坡易发区比非易发区，更显着的盖层类型比直接渗透类型。在盖层型滑坡中，由理论计算得到的火山碎屑岩崩落层中的有效应力随雨水入渗引起的孔隙水压力的增加而减小。因此，在阿索火山碎屑流高原边缘的滑坡是由火山碎屑下降层中的有效应力降低引起的。
The torrential rains of July 2012 caused many landslides at the edge of the Aso pyroclastic flow plateau, consisting of the Aso-3 and the Aso-4 pyroclastic flow deposits in Kyushu Island, Japan. These landslides can be classified into two types: the caprock type, which occurred in Aso-4 areas, and the rainwater direct infiltration type, which occurred in Aso-3 areas. In both types, the landslide sliding surface is located in the lower pyroclastic fall layer of the pyroclastic flow deposit. The maximum hourly precipitation and effective precipitation with a half-life of 1.5 h control landslide occurrence and differ between landslide-prone and non-prone areas and between caprock and direct infiltration types. These parameters are larger in landslide-prone areas than in non-prone areas and are more significant in the caprock type than in the direct infiltration types. In a caprock type landslide, the effective stress in the pyroclastic fall layer estimated by theoretical calculations decreases with increased pore water pressure due to rainwater infiltration. Therefore, the landslide at the edge of the Aso pyroclastic flow plateau was caused by a decrease in effective stress in the pyroclastic fall layer.