Experimental Study on Resistance of Reinforced Levee Against Compound Disaster of Earthquake and Flood

Japan is a high-risk country due to various natural disaster such as earthquake, tsunami, flood, sediment, volcano disasters. In general, countermeasure of natural disaster in rivers may be separately established for earthquake and flood disasters because possibility of occurrence of compound disaster due to earthquake and flood may be regarded to be too low. In Japan, compound and continuous disaster due to earthquake and flood occurred like Fukui Earthquake in 1948 and Kumamoto Earthquake in 2016. However, there are not countermeasure for compound disaster due to earthquake and flood, which are considered separately in planning of river levee.

In the present study, a new experimental channel for the compound disaster was used to examine the resistance of reinforced levees like laminar drain reinforced (LDR) levee against earthquake and overflow in flood phenomenon. The experimental results indicate that the crest settlement of the LDR levee was appreciably smaller than those of other reinforcements mainly due to the prevention to increase excess pore water pressure. It should be noted that the LDR levee with cracks and gaps due to earthquake can maintain the cross-sectional shape of the levee under overflow, showing the high performance of the LDR levee against compound disasters.