A New River Levee Type Using Geosynthetic-Reinforced Soil to Increase Resistance

Yasuo Nihei, Yuki Kurakami, Shohei Kawabe, Yoshiaki Kikuchi, Fumio Tatsuoka, Mayu Morita, Sho Futami

Thursday 2 july 2015

11:45 - 12:00h at Amazon (level 1)

Themes: (T) Water engineering, (ST) River and coastal engineering

Parallel session: 11B. Engineering - River

Overflows of huge floods caused levee breaches in a great number of places around the world. As a reinforcing technology to increase resistance against overflow erosion, we studied on a new type of levee in which Geosynthetic-reinforced soil (GRS) is applied. In the GRS levee, concrete panels connected to geo-grid layers reinforcing the main body of the levee cover the slopes and crest of the levee. The model test revealed that 1) the GRS levee with steep back-slope of 1:0.5 can maintain the high resistance against overflow erosion, showing that it can function effectively as a flood barrier with a small cross-section at a low cost. 2) The GRS levee using relatively short geo-grid layers, not covering the full-width of levee, can keep a high residual ratio of cross-sectional area against overflow for a long time. An appropriate short length of geogrid layers that can exhibit sufficient resistance of the levee against overflow may be selected for a higher cost-effectiveness.