-IB 



X X x Have Height (ft) 



2B 



-+ Hater Elevation (ft, MLW) 

 — Have Period (s) 



25 



3B 



35 



48 



45 



5B 



55 



GB 



65 



Figure 7. Storm profile for SPN from storm of November, 1945 



the flume. Shoreward of the 1 :30 slope, sheet metal was used to repro- 

 duce the steeper portion of the beach profile. A vertical seawall was 

 placed at the top of the slope, and water overtopping the seawall was col- 

 lected and measured to determine overtopping rates. Surveyed profiles 

 and model representations of Profiles 1, 3, 4, and 5 are shown in Figures 8 

 through 11, respectively. 



Seawall elevations varied over the reach represented by each profile. 

 A representative seawall height was selected for each profile except Pro- 

 file 1 ; two representative seawall heights were selected for Profile 1 . 

 Selected seawall elevations are listed in Table 5. 



Beach surveys started at the foot of the seawall, and the elevation at 

 the foot of the seawall was reproduced in all model profiles except Pro- 

 file 1. The beach surveyed at Profile 1 measured an elevation of -1-21.0 ft 

 mlw at the base of the seawall with a seawall crest elevation reported at 

 +21 .4 ft mlw, providing a freeboard of 0.4 ft. However, selected represen- 

 tative seawall elevations for that segment of Revere Beach were +19.8 ft 

 and +20.7 ft, both of which are lower than the beach survey. Because the 

 reaches represented by both seawall elevations were significant, it was de- 

 cided to conduct the Profile 1 test series twice, with one complete set at a 

 seawall elevation of +19.8 ft and one complete set at a seawall elevation 

 of +20.7 ft. For the first set of tests on Profile 1, the profile was modeled 

 such that the beach slope extended to an elevation of + 19.4 ft and then re- 

 mained at a constant elevation until reaching the seawall, resulting in a 

 freeboard of 0.4 ft. For the second set of tests, the same slope was used to 



Chapter 3 Research Tasks A, B, and C 



17 



