When a geotextile's openings are too large for the soil, or a filter is missing altogether, seepage carries fines away and erodes a growing pipe back into the soil. It shows as sinkholes behind walls, muddy drain discharge and settlement over drains. Retention criteria in filter design exist to stop piping, while permittivity and gradient criteria stop the opposite problem, clogging.
Muddy water out of the weep pipes and a sinkhole behind the wall, that's piping, the fabric's too open.
Also heard as
- soil piping
- internal erosion
- soil loss
Related terms
Filtration
Letting water pass across a geotextile while holding back the soil particles it carries.
AOS
Apparent opening size: an index of the largest openings in a geotextile, given as a US sieve number or in millimeters.
Clogging
Gradual loss of flow through a geotextile as soil particles or deposits lodge inside its pores.