MODEL TESTS OP WAVE RUN-UP FOR HIFRICANE PROTECTION PROJECT 



by 



Rudolph P. Savage 



Research Division, Beach Erosion Board 



Studies of protection for coastal areas against erosion damages 

 and lowland flooding associated with the extreme high tide levels and 

 wave action accompanying hurricanes are currently being made in 

 several of the coastal divisions of the Corps of Engineers. A feasible 

 method for providing this type of protection is the restoration or 

 creation of an adequate dune barrier and protective beach by placement 

 of suitable sand fill. In connection with a current investigation of 

 this problem for an area which is exposed to the Atlantic Ocean it was 

 necessary to evaluate the wave run-up to be. expected for certain beach 

 and dune conditions. In order to evaluate the wave run-up, an un- 

 distorted 1:20 scale fixed-bed model of a representative section of 

 the proposed fill and near shore topography of the area was built in 

 a wave tank at the Beach Erosion Board and the wave run-up was measured 

 with tide and wave conditions believed to be representative of storm 

 and/or hurricane design conditions for the area. 



Since these tests give information on one of the problems associ- 

 ated with hydraulic fill design, the data from the tests are being 

 presented for possible use in other problems of this type. It is 

 realized that the conditions encountered in other problems may differ 

 from those given here, but it is believed that the data may have ap- 

 plication in some cases. 



The set-up for the model tests, shown in Figure 1, was installed 

 in a wave tank 96 feet long, 2 feet deep, and 1^ feet wide. The 

 average profile for the offshore section, (see Figure 1) was obtained 

 from a hydrographic survey made in the study area in 1955 and 1956, 

 and was derived by using the intersection of mean sea level with the 

 beach profile as a reference point in both the horizontal and vertical 

 directions and then averaging selected measurements for all profiles 

 except those in the immediate vicinity of jin inlet. Assuming that 

 within a short time after completion of the fill a similar profile 

 would be formed (although located some distance seaward of the original 

 profile), the beach and nearshore topography was constructed in the 

 wave tank to a configuration as near that of the average profile as 

 practicable using straight-line shapes. A dune slope of 1:10 approx- 

 imates the present average value for existing dunes. The offshore 

 bar in the tank model was composed of fine sand covered with a |-inch 

 layer of smooth concrete. The 1:20 beach foreshore slope, 1:10 and 

 lonSdune slopes, and the berm of the beach were constructed of 3/4- 

 inch plywood. 



Preliminary to the actual testing, wave generator settings were 

 determined which would give the desired wave heights seaward of the 



