$(25\%)3.$ The small shelter shown to the left is symmetrical in plan about

both principal axes. Four masonry piers measuring ${24}^{\text{'}\text{'}}{24}^{**}x$

$12\text{'}$ share equally in carrying the roof load.

Roof Dead Load

Roof Live Load

Masonry weight

Allowable axial stress in the masonry

$50\frac{\text{\#}}{t^2}$

$25\frac{\text{\#}}{t^2}$

$120N^{2}f{t}^3$

$200$ psi

a$.$ What is the maximum axial stress, in pounds per square inch

$($psi$),$ in the masonry piers?

Answer

b$.$ If the roof Live Load were increased to $30PSF,$

the maximum axial stress in the pier would:

increase

decrease

not change

If the piers were spaced ${40}^{\text{'}}-0^{\text{'}\text{'}}$ on center, but the overhang remains the same depth

the maximum axial stress in the piers would:

increase

decrease

not change

If the allowable axial stress were increased to $250,$

the maximum axial stress in the piers would:

increase

decrease

not change

If the height of the column is increased to ${15}^{\text{'}}-0^{\text{'}\text{'}},$

the allowable axial stress would:

increase

decrease

not change

If the overhangs were omitted, but the center to center pier spacing remained the same: