Abstract
On offshore disposal site, alluvial clay layer is frequently used as the bottom hydraulic barrier layer. The layer thickness of hydraulic barrier should be thicker than a regulated value, and must not be decreased by the settling and impact of sea-reclaimed wastes. Knowing the settling phenomena of reclaimed wastes is very important to grasp the influences of offshore constructions on the ambient environment. Although the numerical analysis methods for such phenomena have been developed in recent years, it is difficult to develop the appropriate analysis. Here, the results of the free-settling experiments at laboratory and in situ to examine the large Reynolds numbers are reported.
As a result, on free-settling of single particle, the actual settling velocity is 0.5-1.0 times as fast as the terminal settling velocity which is calculated by Newton's experimental equation. On free-settling of multiparticle, the maximum settling velocity is faster than single particle's, though minimum velocity is slower than single particle's. In this case, its actual settling velocity is 0.5-2.0 times as fast as the velocity calculated by the Newton's equation.
