4 Experiments and Results 



Experiments 



Existing conditions 



Comprehensive wave height experiments were conducted for existing condi- 

 tions (Plate 1) to establish a base from which to evaluate the effectiveness of the 

 various improvement plans. Wave height data were secured at various locations 

 in the existing and proposed harbor areas. In addition, wave-induced current 

 patterns and magnitudes and sediment tracer experiments were conducted for 

 representative wave conditions. 



Improvement plans 



Preliminary experiments of proposed improvement plans were initially 

 conducted. These experiments consisted of expeditiously constructed breakwa- 

 ters, causeway extensions, and/or channel alignments. Breakwaters were 

 constructed with concrete blocks in some cases, and with stone in other instances. 

 The stone breakwaters and causeway extensions consisted of an impermeable core 

 (el +0.9 m (+3.0 ft)) with 7,257-kg (8-ton) armor stone constructed to a crest 

 elevation of+4.0m(+13.0ft)on approximate 1V:1.5H side slopes. Deepening 

 of the entrance channels and the turning and deposition basins was accomplished 

 by removing the existing bottom contours and molding pea gravel to the required 

 depths. Wave heights were obtained for most preliminary plans and wave- 

 induced current patterns and magnitudes as well as tracer patterns and subsequent 

 deposits were observed. These experiments were conducted in an expeditious 

 manner only to determine how relative changes would affect hydrodynamic 

 conditions. Results were viewed in a relative sense only due to the nature of the 

 construction. Brief descriptions of preliminary improvement plans are presented 

 in the following subparagraphs; dimensional details are shown in Plates 2-9. 



a. Plan 1 (Plate 2) consisted of the installation of a 808-m-long (2,650-ft- 

 long) block breakwater. The structure originated approximately 463 m 

 (1,520 ft) east of the existing causeway and extended seaward parallel to 

 the causeway 408 m (1,340 ft) before doglegging to the southwest. The 

 navigation opening between the new breakwater and the causeway was 

 213 m (700 ft) wide. 



1 8 Chapter 4 Experiments and Results 



