Sloping Float Breakwater Study Oregon Inlet, North Carolina, Coastal Model Investigation.
Final rept. Jan 81-Jul 84,
COASTAL ENGINEERING RESEARCH CENTER VICKSBURG MS
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Two-dimensional 2-D and three dimensional 3-D hydraulic model investigations were conducted at an undistorted linear scale of 125 model to prototype to acquire data on transmitted wave heights, mooring line forces, intermodule connector forces, bottom impact velocities, and barge angularities as a function of wave climate. These data were needed as input to optimize the design of the sloping float breakwater SFB concept whose function would be to protect floating dredges being used for sand bypassing at Oregon Inlet, N.C. The 2-D test indicated that for the 89.6- and 118.4-ft SFBs a the transmission response of both structures is strongly dependent on wave period b increasing the water depth significantly decreases the wave-attenuating capabilities of both structures c for most wave conditions, mooring forces are similar for both SFB lengths and tend to increase with increasing depth and d peak flow velocities under the structure are generally higher for the longer SFB. The 3-D tests revealed that the existing barge connector concept would be subjected to extremely high forces during impact on a rigid bottom. A softer seafloor condition greatly reduced the connector forces, but since a soft bottom condition could not be guaranteed at all prototype sites, it was determined that the design of the existing connector system for highly rigid bottom-impact forces was not economically feasible. A connector system design that is isolated from these highly rigid bottom-impact forces is feasible, but needs further indepth study. Author
- Civil Engineering