Question

Q4 (50 pts Extra Credit): Design the doubly reinforced concrete beam shown below if it is subjected to a bending moment of 900 k.ft f. = 4,800 psi fy= 60 ksi 27" 15"

Answer 1

MO=10290 Bo-K: 8570502 b=15" d=27" Mu: 900 ki 'ft' 43KS; fya boksi ballan ved bean, capacity of singly reinforced Assuming $=0.70 for balanceel section p=0.01811 х Mo= fx fyx bat? c1 - 0:59 x Theaton) . 7033 +60 0.25 +48xis =7.17 7:17 8:45: com porssion steed. Fue bro 55211 Ś compression fel M1=0.0181460x25 *272 (I - 0:59x6.018)*60 45= 0'0)BIX 18+27= qussin corner semafiting to comed by 900 _857052 = 14248 is compression steel shain dis mbuhón Es = 0.003 x 1954x153 d'agost fs' = 290008 pasuxión? 56.66 ksi Compression stoel: 142.48 As's oill in Stroy -9.5) of tensite reinforcement 70 7:44 inz. buyon See-trit steel coke ce 7:17 Total arca . 53 toill* 56.66 AS-

for tension steel use 5 # 11 bars = 7.8 en As = 5x1.56 for Compression steel use 2 # 3r bars' As = 2xo 'il = 0.22 inz 2 #3 . IS" 27" ?!? ooooo acord hi HS DAY