Based on descriptive passag^es in Iiis paper, values found for D and L^ 

 hj the follcD-ring method should a^oprorimate those he considered. 



215. Given a wave peri-^d, the deep water wave length L (in feet) 

 Jiiaj De found from 



L = 5.12 T^ (26) 



o ^ 



With the ratio d/L , the wave length at the structure L, at depth d r.iay 



be determined from 'the d/L value taken from Table 1 of Jppendiz D. Knowing 



the slope S before the structure^ D may be determined from 



D = d + ]^ S (27) 



Lq may then be determined, again from Table 1 of Appendix D, by coirputing 

 tne ratio D/L , tabulating the corresponding value of d/L (which in this case 

 is D/Lp), and dividing D by this ratio. The h;7drostatic pressure on the 

 seawara side at still water level (subscript "s"), and at the depth d 

 (subscript "d") are given by 



^s " T ^-^ P^ = w (d H- H/2) (28) 



The pressure curve may be plotted by considering that the dynamic pressure 

 is concentrated at still water level, and falls away rapidly along a 

 parabolic curve to zero at a distance 1/2 H above and below still water 

 level. To thJ.s is added the hj^rostatic pressures on the seaward side 

 plotted in a triangular area from 1/2 H above still Xirater level to the 

 bottom, Ifydrc static pressures on the landward side plotted in a triangular 

 area fron still water level to the bottom must be subtracted if such 

 pressures obtain. This constiniction is sho-i-m in Figure 78, the dashed 

 and dotted lines indicating the separate effects of the dynariiic and 

 hj'drostatic pressures, and the solid line the combined pressures, for the 

 case where hydrostatic pressures are on each side of the wall, 



216, The resultant wave thrust or force per linear foot of structure may 

 be determined frora the area of this diagram and is given by 



R = -|: + P^ (d + 1) (29) 



The resultant overturning moment about the ground line before the wall, is 

 the sijjn of the moments of the individual areas and is given by 



P H P^ d^ P H H 



n.J^d^ -^ + _£_ (d •. £ ) • (30) 



3 2 ii 6 



' 108 



