load has an average value of 1.4 kip/ft with a standard deviation of 0.3 kip/ft. The average flexural
resistance of the beam is 230 ft-kip with a standard deviation of 15 ft-kip, and the average shear
resistance of the beam is 45 kip with a standard deviation of 7 kip.
1) [1] Find the global safety factor in both flexure and shear (note: safety factor = resistance/load
effect)
2) [2] Find the safety index in both flexure and shear
3) [3] If the average flexural resistance is increased to 270 ft-kip with the same standard deviation
of 15 ft-kip, find the new safety index in flexure
4) [3] If the standard deviation of the shear resistance is decreased to 5 kip with the same shear
resistance, find the new safety index in shear
5) [1] Comment on your results
25 ft.
Fig. 1. Reinforced concrete beam
LLLLL
Fig: 1