8 A composite breakwater is subjected to a breaking wave wit

8. A composite breakwater is subjected to a breaking wave with the following condi. tions: Wave height, H Wave length, L Stillwater depth to top of substructure, d Depth to bottom, D 20 ft 270 ft 40 ft 70 ft Determine (a) the maximum dynamic pressure and dynamic force per linear foot on the breakwater and (b) the hydrostatic force per linear foot.

Solution

Dynamic pressure on backwater p_m=

101×unt.wt of water×(d_w+D)×d_w×H_b÷(D×L_D)

=101×62.42×(40+70)×40×20÷(70×270)

=29344.5074ft/s²

B) Hydrostatic force=ph²/2

. =62.4×40²/2

   =49920pounds