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11/13/2007 13.56 FAX <br />Project, Pierce Adit Bulkhead, Sta. 3+04 <br />12' Thick, 12' Wide, 12' High, 96 Rebar <br />Q 007/018 <br />By P?2EL/H Date 10/30/07 <br />Shcet 6 of S <br />Reinforced concrete deep-beam bending stress design for earth u:uke acceleration <br />C = ?,J ba = 0.85(3000)12a = 30600a T = A,fy = 60000As <br />C=T 30600a = 60000AS a = (60000 AJ/30600 = 1.961 As <br />Factored earthquake bending moment, IU6:= M n M,, = 279201 ft-lb <br />M <br />A?ai.a,:= 12•M„ M„in = 3350407 in-lb <br />Maximum concrete rebar eove•C, 1:= 12. Lt - m. d = 140.500 in <br />Mai = A,fr(d-a/2) = 60000A,(116 5 - 1.961 A,/2) = 60000 AS - 58831) ASS <br />58830 As2 - 60000 ASd + Muin = 0 941:= 58830 C,121:= -60000-d ,?i:= Kin <br />-C2 - C22 - 4- C I - C3 <br />AS = 0.399 in2 <br />2-C1 <br />One cage of 96 bars (0.44 in2 per bar, 0.750-in nominal diameter., 1.502 lb/ft) on 12.00-in c-c <br />(11.250-in between bars) provides 0.44 in2/ft of steel area. <br />Therefore, ,.451:= 0.440 in- <br />Check for adequacy, <br />Allowable factored bending moment, A,,:=-CI-(As')-C,-A, Au = 3697811 in-lb <br />Design factored bending moment, Muin = 3350407in-lb <br />Factor of safety, A FS = 1.104 <br />Mui11