Internal erosion

Piping (german tube formation) is a form of internal erosion. Here tubular channels are formed in or under is dammed dams, dikes or similar structures of fine-grained Erdschüttmaterial (sand, silt, clay ). The piping can lead to failure, so to break the structure.

Process

Through a dam or dike is accumulated continuously seep small amounts of water. If the seepage flow is too strong, soil particles may be entrained. The erosion starts at a leak on the air side. The flowing water flushes out more and more soil material. It comes to the retrogressive erosion and enlargement of the tube. The removed material leads to the air side conical " Boiling zones ". Achieved the tube, the water side, the water flows freely through the tube and increases the erosion in this. As a result, this can lead to breakage of the structure.

Examples

Examples of dams that were destroyed or damaged by this type of erosion are:

• Baldwin Hills store, California, 1963
• Fontenelle Dam, Wyoming, 1965
• Teton Dam, Idaho, 1976
• Big Bay Dam, 2004