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American Tunnel bu-Lkheads #2 & #3 Page i4 January 15, 2001 <br /> Appendix A. American Tunnel Bulkhead #2 design calculations (Continued) <br /> Earthquake bulkhead design; Load factors (ACI 318-95, Sec 9.2.2, 9.2.3, 9.2.5): Factor for fluid <br /> load under earthquake acceleration(F) = 1.05; Load factor for earthquake accelerated mass <br /> (E) = 1.40. Maximum credible earthquake acceleration(a) is 0.087 S=ft2 . <br /> U= 1.05F+ 1.40E <br /> Loads to be carried by inbye (upstream) rebar of bulkhead resulting from maximum credible <br /> earthquake acceleration of the outbye fluid (F) and bulkhead (E) masses bearing on a 10-ft <br /> thick bulkhead. <br /> E._ Sbywh#+Lhfyc _ [1630(62.4)14(13.5)+10(14)13.5(151)] _ [19,220,000+285,400] _605 800 lb-sec2 <br /> S — 32.2 — 32.2 — ft <br /> E E. =Ema = 605,800(0.087) = 52,700 lb <br /> E= E Em _ 521 = 3 760' <br /> h — 14 ft <br /> Total load under maximum earthquake acceleration for American Tunnel Bulkhead#2, under <br /> 773-ft hydraulic head: <br /> _ Hyw _ 773(62. psi <br /> = 335 <br /> p— 144 — 144 p <br /> F =pbw(12) = 335(12)12 =48,240 a <br /> UQ = 1.05F + 1.40E = 1.05(48240) + 1.40(3760) = 50,650 + 5,260 <br /> UQ = 55,910 a <br /> Earthquake nominal beam bending moment <br /> .12 55910(13.52) = <br /> M►a = 8 8 1,274 000 ft-lb <br /> = <br /> 0 9 — 120.9o00 <br /> M„a = — = 1,193,000 ft.lb (15,290,000 in.lb) <br /> - <br /> Steel area required for earthquake loading: <br /> 58800A3 - 6,990,000As + 15,290,000 =0 <br /> As=2.229 s Steel area required to resist maximum credible earthquake loading for <br /> 10-ft thick bulkhead, i.e. the inbye (upstream) side of the bulkhead. <br /> #10 bars on 6.5-in c-c provide 2.345 a steel area <br />