Suffosion

Suffosion (solution erosion, surface solution) is the rearrangement and the removal of fine soil particles in the soil by water. This fine grains of a non-uniform non-cohesive soil are released from the force of the water flow from the soil and transported by the available pore space. Importantly, in addition to the suffosion the related material from the water displacements due to erosion and silting.

When the fine soil particles are removed through the pores of the larger soil particles, the volume and the structure of the soil is initially maintained, because the skeleton of the coarse soil grains still supported against each other. The density of the Erdstoffes decreases because the pore volume increases. The seepage of water increases as the porosity increases the permeability. The stability may decrease suddenly, and there is the danger of a sudden collapse, for example, of dam structures.

One distinguishes the inner, the outer and Kontaktsuffosion depending on the position of the Suffosionserscheinungen:

Suffosionsgefährdet are Erdstoffe with a relatively large degree of irregularity and especially those that have a grain line with a gap grading. It affects the suffosion opposed by soil filter in accordance with the filtering rules and with geotextiles.