CE 333 Lecture 1 Supplementary Problems Objectives Use load factors and load com

Question

CE 333 Lecture 1 Supplementary Problems Objectives Use load factors and load combinations to calculate required member strengths Explain how load factors vary with structural use . 1. Determine the factored area load, q, demand for a roof beam subjected to the following service loads: Dead load - Snow load Roof live load20 psf Wind load 50 psf 40 psf 20 psf 2. Assume the governing factored area load from Problem 1 is 100 psf, the beam has a span length of 40 ft., and a tributary width of 6 ft., determine the factored moment and shear demand, M, (in units of kip-ft) and V (in units of kip), from the beam in Problem 1 if it were simply supported by a pin and roller at each end. 3. A three-story reinforced concrete building has columns spaced at 18 ft. in both orthogonal directions and is subjected to subjected to roof and floor loads shown below. Using a column load summation table, calculate the cumulative axial loads on a typical interior column. 18 ft (typ.) Roof 18 ft (typ.) Interior Column Third Floor Exterior Column Second Floor Roof Loads 2nd and 3rd Floor Loads Dead load Snow load20 psf Dead Load Live Load -45 psf 50 psf 40 psf

Explanation / Answer

1)per ASCE7-10, the goverming load combinations of interest is

1.2D+1.6S+0.5W =(1.2*50)+(1.6*40)+(0.5*20)=134 psf

Required answer is 134 psf

2)factored uniform load on beam=100*6=600 plf=0.6 klf

Span=40 ft

Factored moment demand=0.6*40²/8=120 kip-ft

Factored shear force demans=0.6*40/2=12 kips

Related Questions

Navigate

• Browse (All)
• Browse C
• Subjects

---