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Tied columns have higher ductility giving less warning before a failure.

Determine the maximum axial strength φPn,max for the following circular tie column.Column diameter, h = 26 in.Number of longitudinal bars = 9Size of longitudinal bars = No. 8Size of ties = No. 4Concrete strength = 6,000 psiYield strength of longitudinal bars = 60,000 psiYield strength of ties = 60,000 psi

In tall buildings, the concrete strength in the columns is often _______ than in the floors because _______.

The interaction diagram for a biaxially loaded column will be a two-dimensional interaction surface.

Which of the follow is not a reason ties are provided in reinforced concrete columns?

Misalignment of a load on a column will produce a moment.

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 = 302 kip and Mu = 26.8 kip-ft.h = 16 in.fc’ = 4 ksify = 60 ksiγ = 0.9ρg = 0.05

A wall footing has the following conditions. Determine the minimum cross-sectional area of the reinforcement. Assume the footing is 3 ft wide and the pressure that acts on the bottom of the footing is 6,666 psf.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 8 kips/ft.The wall is 12 in. thick.The footing is 14 in. thick.The allowable soil pressure, qa, is 5,100 psf.The soil has a density of 130 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.

A wall footing has the following conditions. Determine the minimum cross-sectional area of the reinforcement. Assume the footing is 4 ft wide and the pressure that acts on the bottom of the footing is 4,800 psf.The bottom of the footing is at a depth of 4 ft below grade.The service dead load is 8 kips/ft, and the service live load is 6 kips/ft.The wall is 10 in. thick.The footing is 10 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.

A wall footing has the following conditions. Determine the moment capacity, Mn, of the footing. Assume the footing is 5 ft wide, the pressure that acts on the bottom of the footing is 4,560 psf, and the reinforcement is a #4 bar spaced every 12 inches.The bottom of the footing is at a depth of 5 ft below grade.The service dead load is 11 kips/ft, and the service live load is 6 kips/ft.The wall is 12 in. thick.The footing is 10 in. thick.The allowable soil pressure, qa, is 4,000 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 = 4,000 psi and fy = 60,000 psi.