> 



pile needed below the point of maximum .moment to achieve the ultimate 

 lateral resistance, and may be calculated as 



RCe .+ 1.5D + 0.5f) 1/2 



* = ^5 " (11 > 



and the required pile length 1+ may be calculated directly from equation 

 (9). 



The choice of anchor type should be based on the design loading, the 

 soil conditions, and the available method of placement. No one anchor 

 type is universally suited for all conditions, and each type (or other 

 types not mentioned) should be considered for a particular application 

 and location. 



************* 



V. EXAMPLE PROBLEM ************** 



GIVEN : The typical significant wave height and wave period observed at 

 a site during summer storm conditions are 3.0 feet and 3.0 seconds, 

 respectively, in 6.5 feet of freshwater. 



FIND : 



(1) The width of the Goodyear module FTB that reduces the 

 3.0-foot incident wave height to a 1.0-foot transmitted wave height; 



(2) the expected mooring load (mooring lines are placed on 

 a 1 on 7 slope) ; 



(3) the required weight and volume of a mass concrete anchor; 

 and 



(4) the required length of an anchor pile. 



SOLUTION : 



(1) Find the width of a breakwater that reduces the incident 

 wave height to a 1.0-foot transmitted height. 



(a) Compute the allowable transmission coefficient, 

 K+, using equation (2) : 



* H^ 3.0 ft 



(b) Determine the incident wavelength, L, using 

 equation (1) or Figure 2. From Figure 2 for T = 3.0 seconds 

 and d = 6.5 feet, 



L = 37 ft . 



17 



