Influence of Soil Types on Stabilization of the Savannah River

In order to compare soils in river reaches subject to stabilization problems with those in reaches with adequate depth, bottom samples were taken at six reaches where dikes have been constructed and from five reaches where there are no dikes. Gradation curves of river bottom samples from trouble-free reaches and troublesome reaches does not, in the view of the writer, show an appreciable difference in gradation. Prevailing velocities seem to be the controlling factor in determining the composition of the bottom material and its influence on the navigation channel. Resistance to movement at prevailing velocities of the residual course sand provides a relatively stable river bottom resulting in project conditions as follows: (1) Project width is maintained in relatively sharp bends; (2) savings through reduction of pile penetration and revetment widths required; (3) crossing bars are slow to erode when regulated flow is reduced; and (4) dredging is needed to assist corrective action of dikes.