Erodibility of a Model Soil in a Wide Range of Water Flow Velocities

Resumo

It has been experimentally shown that there are two ranges of water flow velocities, at which the erodibility of a monofractional soil (of aggregates 1–2 mm) sharply differs. In the low-velocity range, the erodibility varies from 171.53 to 3.17 m^–2 s² at an increase in the soil density from 1.2 to 1.5 g/cm³. In the range of high velocities, it varies from 36.88 to 0.88 m^–2 s². The simultaneous solution of equations for the two velocity ranges enables us to obtain the boundary values of the flow velocity. Above them, other erodibility values should be taken into account at calculations. The boundary velocities for the model soil are within 1.6–1.7 m/s. This is explained by the fact that at a slow flow, water removes aggregates, which have lost the contact with the main soil as a result of its peptization by water. At high-velocity water flow, aggregates are detached under the effect of hydrodynamic forces.