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<br />Project As Built Koehler Tunnel Bulkhead By JFA Date 9!6/03 <br />8.42' x 10.5' (12.04' Thick, Sta 3+02) <br />Sheet 4 of 6 <br />Reinforced concrete deep-beam bending stress design for earthquake acceleration: <br />C=~~f~bWa =0.85(3000)12a=30600a <br />C= T 30600 a= 60000 A S <br />Mn <br />Factored earthquake bending M u :_ - <br />moment, ~ rt <br />Minimum concrete rebar cover, d := 12~L ~ - m ~ <br />T=A9f y=60000 A5 <br />a = (60000 A x/30600 = 1.961 A g <br />M a = 583744 <br />ft-16 <br />d = 140.48 in <br />M„=Asfy(d-a/2)=60000As(d-1.961 A~I2)=60000Asd-58830Asz <br />58830 A Sz -60000 A g d+ 12*M ~= 0 C 1 := 58830 C 2 :_ -00000-d <br /> C 1 = 58830 C 2 ='8428800 <br />A :~ -C 2 <br />s <br />2•C 1 <br />A s = 0.836 inz <br />C3:= 12•Mn <br />C 3 = 7004923 <br />One cage of #10 bazs (1.27 inz per bar, 1.270-in diameter) on 14-in c-c (12.73-in between bars) <br />provides 1.089 inz/ft of steel area. <br />Therefore, A s := 1.089 in2 <br />Check for adequacy, <br />22' 4•C 1~C3 <br />Allowable iactoieu benuing moment, A n :_ - t: 1 • iA s~' - C 2~A s <br />Design factored bending moment, M ~• 12 = 7004923 in-lb <br />A <br />Factor of safety, FS := M 12 FS = 1.3 <br />u <br />A n = 9109:95 n-1b <br />~ORte~e,ooa snneoa n~~ n~.++ <br />