Figure 13. Cumulative grain size distribution (by weight) curves for pre- dredged, post-placed, and original foundation materials after mechanical dredging and dump scow placement

ERDC TN-DOER-D2

September 2004

At a coarser-grained dredged material site on the Pacific coast, sandy sediment from the Los

Angeles River was grab-sampled prior to clamshell dredging and split-hull dump scow place-

ment onto the bottom of the North Energy Island fine-grained subaqueous pit. A cap (approxi-

mately 3 ft (1 m) thick) of sandy dredged material was placed through approximately 45 ft

(14.8 m) of water onto a very soft silty-clay foundation material, and some mixing of the dredged

fill and foundation materials was expected. Figures 13 and 14 show the grain size distribution

curves for the pre-dredged sediment, post-dredged fill, and original foundation materials, and

Tables 7 and 8 show selected physical properties.

Figure 13. Cumulative grain size distribution (by weight) curves for pre- dredged, post-placed, and origi-

nal foundation materials after mechanical dredging and dump scow placement

Figure 14. Frequency grain size distribution (by weight) curves for pre- dredged, post-placed, and origi-

nal foundation materials after mechanical dredging and dump scow placement