Assignment

For this exercise consider the three$-$story structural steel building frame shown below. An isometric sketch of the building and a typical bay framing plan is included on the next page $($note column AD is the interior column$).$ Assume the frame is laterally braced $($that is$,$ the effective length factor for all columns $K=1\mathrm{.}0)$ and the steel is ASTM A$992$ with $F_y=50$ksi. Note that a column splice will be used just above the first framed floor as indicated on the elevation sketch $($just above point B$).$ All joints may be assumed to be pinned connections. Neglect live load reduction.

Assume a unit weight of concrete of $150$ pounds per cubic foot; a roof snow load of $40$ pounds per square foot $($PSF$)$; a roof superimposed dead load of $15$ PSF; a floor live load of $65$ PSF; a floor partition load of $15$ PSF; and a floor superimposed dead load of $15$ PSF$.$ The self$-$weight of the column may be neglected.

You are asked to select the lightest W$10$ sections for:

a$)$ Column $AB.$

$(15$ points$)$

b$)$ Column BD $($which extends from the second floor to the roof$).$

$(15$ points$)$