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American Tunnel Bypass a Calculations Page 3 February 28, 1994 <br /> Thickness of thrust ring plate required <br /> Thrust developed in pipe by application of maximum design head of 1550 feet applied to <br /> downstream end of 12-inch Schedule 40 pipe. <br /> ID = 12.000 in OD = 12.750 in <br /> h = Hp = 1550(62.4) = 670 psi <br /> 144 144 <br /> jr(ID2) x(12.0002) <br /> Am = 4 = 4 = 113.10 in2 <br /> T = h(AD) = 670(113.1) = 75800 lb <br /> Area of metal required to support shear stress developed by thrust . Assume 1/2-in thickness, 3 in annulus <br /> Allowable yield stress in shear for annealed stainless steel - 19000psi <br /> (Resistance of Materials, Seely, F.B. & N.E. Ensign, 1952, p469) <br /> COD = it(OD) _ x(12.750) = 40.06 in <br /> Shear area = A. = CODt = 40.06(0.500) = 20.03 in' <br /> Shear stress = Q, = T = 75800 = 3780 psi <br /> A, 20.03 <br /> Shear strength = 20.03(19000) = 3810001b <br /> Factor of Safety = 381000 = 5.03 <br /> 75800 <br /> Compressive stress applied to concrete by thrust ring at maximum thrust load. <br /> Thrust ring ID = 12.750, OD = 18.750 (3-in width). <br /> ;r(D'—D;) ;r(18.7502—12.7502) <br /> Bearing area= B = 4 = 4 = 148.44 in' <br /> Compressive bearing stress = Cb = T = 75800 = 510 psi Factor of Safety= 3000 = 5.88 <br /> B 148.44 510 <br /> Position of thrust ring inside downstream face of American Tunnel Bulkhead to mobilize full section <br /> of bulkhead to resist maximum applied thrust. <br /> Using the 45 degree approximation for stress dissapation within the bulkhead concrete, the required <br /> distance is on half of American Tunnel width of 13 feet, 6.5 feet from the downstream bulkhead <br /> face. <br /> Diameter of High Density Polyethylene (HDPE) pipe to accomodate 2500 gpm under 5-foot <br /> entrance head. <br /> ID= 11.104 in(0.925 ft) OD = 12.750 in(1.063 ft) t= 0.0823 in <br />