Question

Question 4 5 pts The building has beams along building lines A through E and one-way slabs spanning between building lines A through E. A central stalrwell/elevator shaft between bulding lines 5 and 6 provides the lateral support, so only gravity loads need to be calculated The building is used for general affice space. The slab is 8 in. thick. The beams are 12 in. wide and have a total depth of 18 in., the bay dimensions are 18.5 ft in the X direction and 21 ft in theY direction, and the superimpased service dead load is 12 psf. Calculate the factored axial column load lin units of kips) transferred to column C3 from any one of the identical interior floors, Use normal weight reinforced concrete with a unit weight of 150 pcf Do not consider any live load reduction factors 7 bays y'-y :0 따 c)@ 唱 佡 Q: 553zzE5t- E)烹 Plan Elevation 89.2

Answer 1

Unit weight of concrete=150 pcf

Slab thickness=8"

Self weight of slab=(8/12)*150=100 psf

Area of cross section of beam=12*18/144=1.5ft²

Weight of beam=1.5*150/1000=0.225 kip/ft

Superimposed deas load=12 psf

Live load for office space=50 psf

Farctored load on slab=1.2*100+1.6*50=200 psf

Factored weight if beam=1.2*0.225=0.27 kip/ft

Tributary area of column=18.5*21=388.5 ft²

Factored load on column from slab=200*388.5/1000=77.7 kips

Factored load on column from beam weight=18.5*0.27=5 kips

Therefore total factored load on column from each typical floor=77.7+5=82.7 kips