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Larry Perino Page 10 August 17, 2000 <br /> Appendix A. Terry Tunnel near portal bulkhead design calculations (Continued) <br /> AS= 2.344 n steel area required for 7-ft thick bulkhead <br /> #10 bars (1.270 in per bar) on 6-in c-c provides 2.540 a steel area <br /> Check for adequacy <br /> Allowable M„= -58,800A, + 4,830,000OAB= 11,890,000 in-lb <br /> Design Mu = 11,000,000 in-lb <br /> FS = 11 ii 00000000 0000 = 1.08 for 7-ft thick bulkhead <br /> Critical section shear strength for Terry Tunnel, 7-ft deep beam bulkhead <br /> Deep beam defined as e < 5 (ACI 318-95, Sec 11.8.1). Critical section shear at 0.151 (1.90 <br /> ft) from ribside(ACI 318-95, Sec 11.8.5), with#10 bars on 6-in c-c, there will be 2.540 a <br /> of steel per ft of beam width, d = 80.5 in (6.71 ft). <br /> Detailed shear strength at critical section (ACI 318-95, Sec 11.8.7) <br /> 1 _ 12.7c12> _ '52 = 1.89 < 5 Therefore reinforced concrete bulkhead <br /> d [702�3.51 W5 <br /> is a deep beam for design! <br /> vn - nominal shear stress shall not be greater than 8 when a <2 <br /> (ACI 318-95, Sec 11.8.4) <br /> Limiting value: v„ <8 3 000 <438 psi Vn <(vn)b,yd <(438)12(80.5) <423,100 lb <br /> Vn= z� —(i�)\o sll� = 0.35co1 =0.35(40900)12.7 = 181,800 lb <br /> VU = 5== olas0 = 213,900 lb <br /> (21)(0.15 1)—co(0.15 1)0-25� = 0.06375 22 =0.06375[409((12.72)] <br /> M„=210,300 ft-lb <br /> > = Mn = 210 900 =233,700 ft-lb <br /> 0.V� =K(1.9 f� +2500p,,Ma)b,yd <br />