Table 15 



Test Conditions and Overtopping Rates for Park Dike with 1991 



Profile 



Run No. 



SWL 

 ft mlw 



Wave 



Height 



ft 



Wave 



Period 



sec 



Seawall 

 Crest 

 Elev. 

 ft mlw 



Dike 

 Crest 

 Elev. 

 ft mlw 



Beach 

 Elev. 

 ft mlw 



Over- 

 topping 

 cfs/ft 



1 



16.6 



12.7 



15.9 



21.3 



24.0 



20.5 





2 



16.6 



12.7 



13.0 



21.3 



24.0 



20.5 





3 



16.6 



12.7 



15.9 



20.9 



24.0 



20.5 





4 



16.6 



12.7 



13.0 



20.9 



24.0 



20.5 





5 



16.6 



12.7 



15.9 



20.9 



24.0 



15.4 



0.0003 



6 



16.6 



12.7 



13.0 



20.9 



24.0 



15.4 



1 



7 



17.6 



12.7 



15.9 



20.9 



24.0 



15.4 



0.0068 



8 



16.6 



12.7 



15.9 



25.9 



2 



15.4 



0.0083 



9 



17.6 



12.7 



15.9 



20.9 



25.7 



15.4 



0.0011 



10 



17.6 



12.7 



15.9 



20.9 



25.7 



20.0 



0.0009 



11 



17.6 



12.7 



15.9 



21.3 



27.5 



20.6 



0.0003 



^ Overtopping too low to be measured. 

 ^ Overtopping of seawall, not park dike. 



of depth greatly increased the overtopping rates to nearly 0.007 cfs/ft 

 (prototype). 



Test 8 increased the seawall crest elevation by 5 ft to +26.9 ft mlw to 

 determine if an increase in seawall crest would prevent overtopping with- 

 out the expense of the park dike. Overtopping was measured directly be- 

 hind the seawall and averaged 0.008 cfs/ft. The additional foot of depth 

 used in Test 7 was not used in Test 8. 



Tests 9 through 1 1 brought the swl back up to +17.6 ft mlw. Tests 9 

 and 10 raised the crest of the park dike to +25.7 ft mlw and used beach 

 elevations of +14.4 and +19.9 ft mlw, respectively. Test 1 1 raised the 

 park dike crest elevation to +27.5 ft mlw, returned the seawall crest eleva- 

 tion to +21.3, and replaced the sheet metal slope in front of the seawall to 

 a beach elevation of +20.6 ft mlw. The park dike was overtopped in all 

 three tests. 



Chapter 5 Revere Dike Study 



49 



