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To account for the effect of accidental moments, the ACI Code specifies that the maximum load on a column must not exceed 0.85 times the axial-load capacity of spiral columns and 0.80 times the axial-load capacity of tied columns.

A wall footing has the following conditions. Determine the minimum cross-sectional area of the reinforcement. Assume the footing is 6 ft wide and the pressure that acts on the bottom of the footing is 4,133 psf.The bottom of the footing is at a depth of 5 ft below grade.The service dead load is 10 kips/ft, and the service live load is 8 kips/ft.The wall is 14 in. thick.The footing is 10 in. thick.The allowable soil pressure, qa, is 4,100 psf.The soil has a density of 115 lb/ft3.The concrete has a density of 150 lb/ft3.The concrete cover has a thickness of 3 in.f’c = 3,100 psi and fy = 60,000 psi.

A wall footing has the following conditions. Determine the critical one-way shear, Vu, at a distance of d from the face of the wall. Assume the footing is 4 ft wide, the pressure that acts on the bottom of the footing is 4,599 psf, and the reinforcement is a #4 bar spaced every 12 inches.The bottom of the footing is at a depth of 3 ft below grade.The service dead load is 6 kips/ft, and the service live load is 7 kips/ft.The wall is 14 in. thick.The footing is 10 in. thick.The allowable soil pressure, qa, is 4,400 psf.The soil has a density of 125 lb/ft3.The concrete has a density of 150 lb/ft3.The concrete cover has a thickness of 3 in.f’c = 3,800 psi and fy = 60,000 psi.

A wall footing has the following conditions. Determine the moment capacity, Mn, of the footing. Assume the footing is 4 ft wide, the pressure that acts on the bottom of the footing is 6,500 psf, and the reinforcement is a #4 bar spaced every 12 inches.The bottom of the footing is at a depth of 4 ft below grade.The service dead load is 11 kips/ft, and the service live load is 8 kips/ft.The wall is 10 in. thick.The footing is 13 in. thick.The allowable soil pressure, qa, is 5,800 psf.The soil has a density of 120 lb/ft3.The concrete has a density of 150 lb/ft3.The concrete cover has a thickness of 3 in.f’c = 3,800 psi and fy = 60,000 psi.

Solving a design problem typically involves guessing a section, analyzing whether it will be satisfactory, revising the section, reanalyzing it.

Determine the required splice length for the galvanized longitudinal bars in the following tied column made of normal-weight concrete. Assume that some of the longitudinal bars are in tension and that the connection should be designed as a Class B contact lap splice. Use ACI 318-14 Table 25.4.2.2 to calculate the development length, and assume that the ties satisfy the Code minimum.Column width, b = 20 in.Column thickness, h = 28 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 10Size of longitudinal bars = No. 10Size of ties = No. 3Concrete strength = 8,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

Determine the required splice length for the uncoated longitudinal bars in the following tied column made of normal-weight concrete. Assume that some of the longitudinal bars are in tension and that the connection should be designed as a Class B contact lap splice. Use ACI 318-14 Table 25.4.2.2 to calculate the development length, and assume that the ties satisfy the Code minimum.Column width, b = 20 in.Column thickness, h = 18 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 10Size of longitudinal bars = No. 7Size of ties = No. 4Concrete strength = 4,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

Use the interaction diagrams found in Appendix A of the textbook to determine whether the following circular spiral column can safely support a load of Pu = 704 kip and Mu = 241.3 kip-ft.h = 16 in.fc’ = 4 ksify = 60 ksiγ = 0.9ρg = 0.02

Determine the required splice length for the longitudinal bars in the following tied column. Assume that all of the longitudinal bars are in compression and that you will use a contact lap splice. Do not incorporate a reduction in length due to ACI 318-14 Section 10.7.5.2.1.Column width, b = 26 in.Column thickness, h = 28 in.Clear cover to ties = 1.5 in.Number of longitudinal bars = 12Size of longitudinal bars = No. 10Size of ties = No. 4Concrete strength = 4,500 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 40,000 psi

A wall footing has the following conditions. Determine the shear capacity, φVn, of the footing. Assume the footing is 4 ft wide, the pressure that acts on the bottom of the footing is 5,200 psf, and the reinforcement is a #5 bar spaced every 12 inches.The bottom of the footing is at a depth of 2 ft below grade.The service dead load is 8 kips/ft, and the service live load is 7 kips/ft.The wall is 16 in. thick.The footing is 12 in. thick.The allowable soil pressure, qa, is 4,400 psf.The soil has a density of 115 lb/ft3.The concrete has a density of 150 lb/ft3.The concrete cover has a thickness of 3 in.f’c = 3,400 psi and fy = 60,000 psi.