Piping
Definition
Internal erosion in an embankment or foundation in which seepage flow progressively removes fine particles along a concentrated flow path until a continuous tunnel forms and the structure collapses. The dominant failure mode for earthen dams.
- Process
- Internal erosion along a concentrated seepage path
- Structure type
- Earthen dams and levee foundations
- End state
- Continuous erosion tunnel leading to collapse
- Failure ranking
- Leading cause of embankment dam failure worldwide
Common questions
What conditions make an embankment susceptible to piping?+
Fine, erodible soil in the embankment or foundation, a concentrated seepage exit point such as a crack or animal burrow, and insufficient filter protection at the downstream face all raise the risk. Poorly compacted zones near conduits or abutments are common starting points.
How is piping distinguished from slope-stability failure at a dam site?+
Piping is driven by internal seepage removing particles along a defined path, often visible as boils or cloudy discharge at the toe before collapse, whereas slope failure is a mechanical shear event along a rotational surface. Forensic investigators look for eroded channels or sinkholes rather than a rotated failure scarp.
Related terms
- Bearing Capacity
- The maximum stress a soil or rock can sustain beneath a foundation without shear failure. Expressed as ultimate bearing capacity (at failure)...
- Cone Penetration Test (CPT)
- A continuous in-situ test pushing an instrumented cone through the soil and measuring tip resistance and sleeve friction. Provides a nearly continuous...
- Differential Settlement
- Non-uniform vertical movement of different parts of a foundation, distorting the structure it supports. More damaging than uniform settlement because it induces...
- Liquefaction
- Loss of shear strength in saturated granular soil when earthquake-induced cyclic loading causes pore water pressure to equal the total stress, reducing...
- Standard Penetration Test (SPT)
- An in-situ test measuring the number of blows to drive a split-spoon sampler 300 mm into the soil at a given depth....