The destructions of river dikes were reported due to heavy rainfall in recent years, and this situation may become worse in the future. If the detections for the vulnerable areas in dikes are available, we can take measures to minimize the damages. The goal of this research is to evaluate the stability of them against heavy rain and to hind out dangerous points. I would like to bulid a unsaturated seepage model with the predictable climate data, and create a hazard map for the Chikugo River finally.
In this study, finite element analysis was performed on unsaturated seepage with assuming rising river water levels in the future to create a risk map of the Chikugo River, focusing on damaged river levees due to heavy rainfall. Section river levees reviewed consist of from the upstream, middle and downstream of the Chikugo river and use the hydrograph of the river level downscaled from the future climate data as an external force, and considerate potential seepage destruction of river levees in the Chikugo river basin.
My study started from the ground improving technologies of building’s foundations for the liquefaction damages in the 2011 Great Tohoku Earthquakes. Recently, I introduced the Bender elements into the cyclic tri-axial tests system to discuss the variation relations between shear modulus G and effective stress σ’ of sandy soils and volcanic soils during liquefaction and re-liquefaction after the 2016 Kumamoto Earthquakes.
