Publisher:
ISBN:
Category : Craney Island (Va.)
Languages : en
Pages : 41
Book Description
Several alternatives were investigated to replace or extend the 2,500-acre Craney Island Disposal Area for continued dredged material disposal for the Norfolk harbor and channels. The disposal area was completed in 1957 and has been used continuously since that time and the dikes have been raised several times to the present e1 +26 ft Mean Low Water (MLW). Because of new plans to deepen the existing channel and continued maintenance dredging, the estimated storage life has greatly reduced. Five alternate configurations of the extension of Craney Island to the west and/or north were investigated as to their estimated storage capacity, their effect on the hydrodynamics of the harbor and river system, and the stability and constructibility of the retaining dikes which is the subject of this report. It was determined that: 1) it is technically feasible to design and construct the required dikes to e1 +8 ft MLW by hydraulic placement of sand; and 2) these dikes could be protected from erosion by the placement of riprap on the inside and outside slopes. The most economically feasible alternatives for storage capacity were configurations 5 and 2 which had an estimated cost per cubic yard of storage of $0.58 and $0.70, respectively. Keywords: Dike stability.