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<br />48 <br /> <br />For example, two feet of water hitting the broadside of a 50 ft by 30 It house and a <br />velocity of 7.5 fps, Based on depth of water versus width ratio of 25, the Cd factor is <br />approximately 1.3. <br />V' <br />Pd = CdP 2 <br /> <br />= 1.30(1.94) (7.5)' <br />2 <br /> <br />= 70.9 Iblft' <br /> <br />FD = Pd x area <br /> <br />= 70,9 x (2) x (50) <br />= 7,093 Ibs <br /> <br />The resultant force FD is assumed to act at the center of its applied area, or at the one foot <br />levelD in the example. <br /> <br />For cases when water velocities do not exceed 10 fps, dynamic effects of the water may be <br />converted to equivalent hydrostatic loads. The calculation is: <br /> <br />dh = CdV' <br />'Ig <br /> <br />Acceleration of gravity, g, is 32.2 fps, The depth, dh, is in feet and is added to the design <br />depth of water only on the upstream side of the building. This eliminates the separate treat- <br />ment of hydrodynamic loads. <br /> <br />For the same previous example used to calculate PD' the increased water depth for an <br />equivalent hydrostatic load would be: <br /> <br />dh = CdV' <br />2g <br /> <br />= (1.3)(7.5)' <br />2(32,2) <br /> <br />~ 1,1 ft <br /> <br />The effective depth would be 2 + 1,1 = 3,1 feet. <br />