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<br />2, Comnutinq pier S:our. <br /> <br />is as follows: <br /> <br />The Colorado state University equation (7) <br /> <br />Ys <br />= <br />Y, <br /> <br />Where: <br /> <br />2 ,C K, K2 (~) 0 .65 <br />Y, <br /> <br />;:;>.... 0.43 <br />. ~l <br /> <br />(9 ) <br /> <br />Ys = scour depth <br />Y, = flow depth just upstream of the pier <br />K, = correction for pier nose shape from ?igure 4,7 <br />and Table 4.3 <br />K2 = corre,:tion for angle of attack of flo.,J froI7l <br />Table 4,4 <br />a = pier width <br />Fr, = Froud,. number = v,/(gy,)o.s <br /> <br />(a) <br />(b) <br />(c) <br />(d) <br />(e) <br /> <br />Shane of pier Nose <br />Square nose <br />Round nose <br />Circular cylinder <br />Sharp nose <br />Group of cylinders <br /> <br />TABLE 4.2 CORRECTION FACTOR, K1 <br />for PIER NOSE SHAPE <br /> <br />TABLE 4.3 CORRECTION FACTOR, K2 <br />for ANGLE of ATTACK <br />of the FLOh' <br /> <br />K- <br />1.1 <br />1.0 <br />1.0 <br />0,9 <br />1.0 <br /> <br />J:>.nqle L/a=4 L/a=8 L/a=12 <br />0 1.0 1.0 1.0 <br />15 1.5 2.0 2,5 <br />30 2.0 2.5 3.5 <br />45 2.3 3.3 4,3 <br />90 2.5 3.9 5.0 <br /> <br />Angle = skew angle of flow <br />L = length of pier <br /> <br />Note. The correction factor k, for pier nose shape should be <br />determined using Table 4.2 for flow angle of attack up to 5 <br />degrees, For greater angles, pier nose shape loses its affect <br />and k, should be consid~red as 1,0, <br /> <br />52 <br />