Problem 1 The simply supported beam is subjected to a cubically distributed ultimate load given by: ? 3 ?, (?) = ??? ?3 where the load intensity at the right support is ? ??? = 5 kip/ft and ? = 30 ft. Assume a concrete compressive strength of fr = 4500 psi and steel yield strength of f = 60 ksi. By selecting p = 0.5 P?' where = P? balanced steel area ratio, determine the effective depth d and the required reinforcement area A, at the critical section. Use the ACI 318 code value for in your design. b=12" Cubic variation of ultimate load Wmax d As 2.5" Section T L