The floor framing in an office building consists of reinforced concrete beams 18 in. × 24 in. deep that support precast concrete planks on a 3-in. ledge similar to that shown in Figure. The clear span of the beam is 27 ft between columns. The planks are 10-in. deep with 2-in. topping and supports stud wall partitions that weigh 10 psf and mechanical/electrical equipment that weigh 5 psf. The weight of the precast planks is 70 psf. The centerline to centerline span of the planks is 30 ft on the left-hand side of the beam and 10 ft on the right-hand side of the beam. The live load on the 30-ft span is 50 psf while the live load on the 10-ft corridor span is 100 psf. Design the beam for torsion and shear assuming normal weight concrete (i.e., λ = 1.0), f′ c = 4000 psi and fy = 60,000 psi. Assume the beam has already been designed for bending.
