Overtopping breaching of river levees constructed with cohesive sediments
Experiments were conducted in a bend flume to study the overtopping breaching process and the corresponding overflow rates of river levees constructed with cohesive sediments. The river and land regions were separated by the constructed levee in the bend flume. Results showed that the levee breachin...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2016-07-01
|
| Series: | Natural Hazards and Earth System Sciences |
| Online Access: | http://www.nat-hazards-earth-syst-sci.net/16/1541/2016/nhess-16-1541-2016.pdf |
| Summary: | Experiments were conducted in a bend flume to study the
overtopping breaching process and the corresponding overflow rates of river
levees constructed with cohesive sediments. The river and land regions were
separated by the constructed levee in the bend flume. Results showed that
the levee breaching process can be subdivided into a slope erosion stage, a
headcut retreat stage and a breach widening stage. Mechanisms such as flow
shear erosion, impinging jet erosion, side slope erosion and cantilever
collapse were discovered in the breaching process. The erosion
characteristics were determined by both flow and soil properties. Finally, a
depth-averaged 2-D flow model was used to simulate the levee breaching flow
rates, which is well expressed by the broad-crested weir flow formula. The
deduced discharge coefficient was smaller than that of common broad-crested
rectangular weirs because of the shape and roughness of the breach. |
|---|---|
| ISSN: | 1561-8633 1684-9981 |