Mayport-Mill Cove Model Study. Report 3. Mill Cove Study. Hydraulic Model Investigation

摘要

A fixed-bed model of Mayport-Mill Cove constructed to scales of 1:500 horizontally and 1:50 vertically, reproduced a portion of the Atlantic Ocean adjacent to the entrance and the St. Johns River upstream to Hibernia Point. The purpose of the model study was twofold: (a) to investigate the effects of proposed improvement plans for the Mayport Naval Basin area on existing shoaling rates, hydraulics, salinities, and flushing; and (b) to investigate the effects of proposed improvement plans in the Mill Cove area on flushing, hydraulics, salinities and channel shoaling. The model verification tests described in Report 1 indicated that the model hydraulic and salinity regimes were in satisfactory agreement with those of the prototype for comparable conditions. Based on visual observations and analysis of surface current pattern photographs conducted for 20 proposed plans, 3 plans (15, 18 and 20) were selected for further, more extensive testing. Each plan involved an enlarged weir opening 1,300 ft wide by 12 ft deep at msl and the relocation of approximately, 1,400 ft from the west end of the disposal island located off Reddie Point to the east end of the disposal island. Plan 15 included the above weir and disposal island changes in addition to the construction of a triangular-shaped island inside Mill Cove. Plan 18 involved only the above weir and disposal island changes. Plan 20 included the above weir and disposal island changes in addition to an enlargement of Quarantine Island into Mill Cove.