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Ransom Tunnel Bulkhead Page 5 May 7, 1997 <br /> Plain concrete deep-beam bending stress design, Ransom tunnel (ACI 318-95, Sec 9.9.2.5, <br /> 18.4.1(b), & ACI 318-71, Sec 9.2.1.5) <br /> Ransom Tunnel bulkhead, for 635-ft hydraulic head (275 psi pressure head): <br /> u�=U= 1.4p(144) = 1.4(275)144= 55,400 (n <br /> = g2 — ssao8(132) = 692,500 ft-lb <br /> = Mn — 692500 = 1,065 000 ft-lb <br /> 0.65 — 0.65 <br /> bL3 I(OX123) <br /> _ <br /> S I _ Iz _ 12 _ 1440 <br /> — L — U12) — 6 <br /> 2 2 <br /> f'Cl =3 f, = 3 13000 = 164 psi <br /> �I Muc Mu 1065000 44400 <br /> 14cl = 164 =Q= I = S = 144L2 — L,2 <br /> 6 <br /> L — 4 6440 — 271 = 16.5 ft, length required for plain concrete <br /> bulkead. <br /> Mu Mu 1065000 1065000 <br /> Qg — $ — 144L2 — 144(82) — 1536 — 693 psi <br /> 6 6 <br /> r <br /> 164. <br /> FS — vs = 693 = 0.24 <br /> Therefore, 8-ft long plug must be reinforced. <br /> Reinforced concrete deep-beam bending stress design, Ransom tunnel (ACI 318-95, Sec 9.3.2.3, Sec <br /> 9.3.2.3.: Wang& Salmon, 1985: Einarson & Abel, 1990) <br /> C= �fcb,, = 0.85(3000)12a= 30600a <br /> T = Asfy = 60000A,, <br /> C = T• a= 63006000 = 1.961 A, <br /> � <br /> 82 — ssao8(1o2) = 692,500 ft-lb <br /> M„= 0.9 — 6909 0 = 769,400 ft-lb (9,233,000 in-lb) <br /> NL My(d—i); d =L - m,= 8(12) - 3.5 =92.5 in <br /> 5 <br />