water viscosity, and distance of wave travel, and the model data can be corrected 

 and converted to their prototype equivalents. 



Experiments and Results 



Experiments 



Existing conditions. Comprehensive wave-height experiments were con- 

 ducted for existing conditions (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 marina. In addition, wave-induced 

 current patterns and magnitudes, sediment-tracer experiments, and wave-pattern 

 photographs were obtained for representative wave conditions. Wave heights in 

 the marina also were measured as a result of wakes from various vessels 

 navigating the St. Clair River. 



Improvement plans. Wave-height experiments were obtained for 16 plan 

 configurations. In general, variations consisted of changes in the lengths, align- 

 ments, or elevation of the breakwaters and/or the installation of stone adjacent to 

 the existing structures. Sediment-tracer patterns and subsequent deposits, wave- 

 induced current patterns and magnitudes, wave-pattern photographs, and vessel- 

 wake experiments were obtained for some of the improvement plans. Brief 

 descriptions of the improvement plans are presented in the following subpara- 

 graphs; dimensional details are shown in Plates 2-10. 



a. Plan 1 (Plate 2) consisted of the installation of a 12.2-m (40-ft) sheet-pile 

 extension of the outer north breakwater along its original alignment. The 

 breakwater extension was constructed of Plexiglas at the elevation of the 

 existing structure (+2.1 m (+7.0 ft) LWD). 



b. Plan 2 (Plate 2) included the installation of an 18.3-m (60-ft) sheet-pile 

 extension of the outer north breakwater along its original alignment. 



c. Plan 3 (Plate 2) entailed the installation of a 24.4-m (80-ft) sheet-pile 

 extension of the outer north breakwater along its original alignment. 



d. Plan 4 (Plate 3) involved the 24.4-m (80-ft) sheet-pile extension of Plan 3. 

 In addition, a 24.4-m-long (80-ft-long) stone absorber was installed along 

 the portion of the north breakwater with the north-south alignment on its 

 lakeward side. The absorber consisted of 9,070-kg (10-ton) stone with an 

 el of +2.13 m (+7.0 ft) and was placed on a 1V:1.5H slope. 



e. Plan 5 (Plate 4) consisted of a 39.6-m-long (130-ft-long) sheet-pile 

 breakwater that was attached to the existing breakwater at the northeast 

 comer of the harbor and extended southeasterly terminating at the same 

 point as the Plan 1 structure extension. The existing north breakwater was 

 left in place. 



Chapter 6 Physical Model 41 



