Piping
Piping (engl. Tube formation ) is a form of internal erosion . This creates tube-like channels in or under dammed-up dams , dikes or similar structures made of fine-grained bulk material (sand, silt, clay). The piping can lead to failure , i.e. the breakage of the structure.
process
Small amounts of water constantly seep through a dammed dam or dike. If the seepage flow becomes too strong, soil particles can be carried away. The erosion begins at a leak on the air side . The flowing water washes out more and more soil material. There is regressive erosion and enlargement of the tube. The removed material leads to conical “boiling zones” on the air side. If the tube reaches the water side, the water flows unhindered through the tube and increases the erosion in it. As a result, this can lead to breakage of the structure.
Examples
Examples of dams destroyed or damaged by this type of erosion include:
- Whinhill Reservoir , Greenock, Scotland, 1835
- Baldwin Hills Storage , California, 1963
- Fontenelle Dam, Wyoming, 1965
- Teton Dam , Idaho, 1976
- Big Bay Dam , 2004
Web links
- The scaling law of piping erosion (PDF file; 898 kB)
- Development of piping erosion conditions in the Benson area, Arizona, USA
- Piping in Embankment Dams