Geometry for CAD Projects (COnt.)

Bulking is an important consideration for CAD geometry. The volume

of contaminated material and cap and associated bulking must be closely

estimated to ensure that all the material and cap can be placed within the

available contained volume. For mechanically dredged sediments, bulk-

ing of 10 to 40 percent (Bray, Bates, and Land 1997) is reasonable. For

hydraulically dredged sediments, dredged and placed by hopper or pipe-

line, much of the excess water will be expelled as the material is placed

within the CAD site, but the volume occupied during the placement opera-

tion must be closely estimated. A project-specific investigation of the ex-

pected increase in volume for a particular dredging/placement method and

sediment is warranted. Sedimentation analysis to determine a volume oc-

cupied by hydraulic pipeline placement to a CAD site has been conducted

using procedures developed for diked confined disposal facilities (Averett

et al. 1989). Procedures for such an analysis are outlined in detail in the

USACE Engineer Manual 1110-2-5027, Confined Disposal of Dredged

Material (USACE 1987).

Chapter 6 Sediment Dispersion and Mound Development and Site Geometry During Placement