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American Tunnel bu-Lkheads #2 & #3 Page z2 January 15, 2001 <br /> Appendix B. American Tunnel Bulkhead #3 design calculations (Continued) <br /> Loads on bulkhead resulting from maximum credible earthquake acceleration of the inbye fluid (F) <br /> and bulkhead (E) masses bearing on a 11-ft thick bulkhead. <br /> _ S17whQ+LhQ7c _ [1630(62.4)15(12)+11(15)12(151)1 _ [18,310,000+299,0001 1b 2 <br /> Em 9 — 32.2 — 32.2 = 577,900 ft <br /> E E. =Ea= 577,900(0.087) = 50,280 lb <br /> E = E E. 50280 = 3 3501b <br /> h = 15 , ft <br /> Total load under maximum earthquake acceleration for, under 773-ft hydraulic head: <br /> _ Hyw _ 773(62.4) = 335 Sl <br /> p— 144 — 144 p <br /> F =pb,,(12) = 355(12)12 =48,240 a <br /> Ua = 1.05F + 1.40E = 1.05(48240) + 1.40(3350) = 50,650 +4,690 <br /> Ua = 55,340 n <br /> Earthquake nominal beam bending moment <br /> u8Q2 ss34g(1zZ) = 996,100 ft-lb <br /> Mn 0.9 — 990.9 0 = 1,107,000 ft•lb (13,280,000 in-lb) <br /> Mua = <br /> - - <br /> Steel area required for earthquake loading: <br /> 58800A2 - 7,710,000A, + 13,280,000=0 <br /> As= 1.746 s Steel area required to resist maximum credible earthquake loading for 11-ft <br /> thick bulkhead <br /> #10 bars on 7-in c-c provide 2.177 s steel area <br /> Check for adequacy <br /> Allowable M„a =-58,800A2 +7,710,OOOAs = 16,510,000 in-lb <br />