STRESS ANALYSIS OF RIVER EMBANKMENT CONSIDERING EXTERNAL WATER LEVEL FLUCTUATION

In recent years, local downpours frequently occur in various parts of Japan, and embankments are destroyed by these downpours. Many embankments are historical products of flood control that have been reinforced as they age by raising their height. However, the structure of the river embankment was developed based on information from disasters that actually occurred, and analysis of the destruction of the structure was not considered in design. Furthermore, until now, mechanisms of levee collapse have been discussed, but they have not been fully elucidated. Therefore, in this study, embankment analysis considering difference of layer thickness was performed by using the unsaturated soil / water / air coupled element finite method analysis program (DACSAR-MP). Stress behavior in the embankment during the rise of the river water level due to rainfall was analytically expressed, and the effect of the stress was considered to analytically investigate the collapse mechanism of the river embankment. From this work, it was analytically confirmed that embankment failure mode differed depending on differences in the speed of water level rise.