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<br />I <br />1- <br />l.-' \ <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br />I <br /> <br />PIER SCOUR EQUATION <br /> <br />Equation 12: The Colorado State University's equation (Richardson et al, 1987) <br />is as follows: <br /> <br />Where: <br /> <br />1. = 2 0 K K (A-)o.e. Fr.o.43 <br />Y. . .. Y. . <br /> <br />Y. = scour depth <br />Y. = flow depth just upstream of the pier <br />K. = correction for pier shape from figure 4.14 and table 4.2 <br />Kz = correction for angle of attack of flow from table 4.3 <br />a = pier width <br />Fr, = Froude number = V, <br /> <br />(12) <br /> <br />(gy.)o.. <br /> <br />TABLE 4.2 Correction Factor, K. <br />for Pier Type <br /> <br />TABLE 4.3 Correction factor, K. <br />for Ingl. of attack <br />of the now <br /> <br />(a) <br />(b) <br />(c) <br />(d) <br />(e) <br /> <br />Type of Pier K, <br />Square nose 1.1 <br />Round nose 1.0 <br />Circular cylindar 1.0 <br />Sharp nose 0.9 <br />Group of eylindars 1.0 <br /> <br />Angl. <br />o <br />15 <br />30 <br />45 <br />90 <br /> <br />L/a=4 <br />1.0 <br />1.5 <br />2.0 <br />2.3 <br />2.5 <br /> <br />l/a=8 <br />1.0 <br />2.0 <br />2.5 <br />3.3 <br />3.9 <br /> <br />L/a=12 <br />1.0 <br />2.5 <br />3.5 <br />4.3 <br />5.0 <br /> <br />Angle = skew angle of flow <br />L = length of pier <br /> <br />L <br /> <br />L <br /> <br />1:1 <br /> <br />I <br />.1:1 <br /> <br />ill <br /> <br />(a) Square nose <br /> <br />(b) Round nose <br /> <br />(e) Cylindar <br /> <br />L <br /> <br />J <br /> <br />L <br /> <br />md <br /> <br />rk <br /> <br />(d) Sharp nose <br />FIGURE 4.14 <br /> <br />(e) Group of eylindars <br />ClMlON SHAPES <br /> <br />41 <br />