Problem $2.$ Recall Problem $1$ in HW $6($see figure on next page$).$ You determined the loading $($FBDs$)$ and calculated the reactions for several members. Make sure to use that information when solving this problem. Given the two$-$story building with roof and floor plan shown on the next page: Roof unit dead load $=10$ psf; Roof unit live load $=20$ psf$.$ Floor unit dead load $=15$ psf; Floor unit live load is $40$ psf$.$ Plaster ceiling is assumed for roofsAll members $($beams$,$ girders, columns$)$ are made of Douglas$-$Fir lumber. For beam B$-4$ in part $($d$)$ there is also the option to use glulam.

a$)$ Draw the shear and moment diagrams and determine the size of a typical interior secondary roof beam, B$1,$ spanning $24$ ft$.$ Size for bending

and verify for shear and deflections.

b$)$ Draw the shear and moment diagrams and determine the size of a typical imerior primary roof girder, G$1,$ spanning $24$ ft$.$ Size for bending and verify for shear and deflection.

c$)$ Determine the size of the continuous square column between the roof and ground at B$-1($that is intersection of column lines B and $1).$ Assume the column is pin restrained at the ground and ateach story level. Use a factor of safety for buckling, $$2=2.$

d$)$ Draw the shear and moment diagrams and determine the size of the interior secondary floor beam, B$4$ circled in the figure, spanning $16$ ft$.$ Size for bending and verify for shear and deflection. Note that beam B$4$ supports column CC and part of the deck. The load on column CC comes from girders G$1$ and G$2.$For this beam you have the option to use sawn lumber $($Table B$-1$ in Handout $3)$ or glulam. For sawn lumber you will need two sections side by side.If you select to use glulam, the geometric properties are listed in Table A$10$ in OK Appendix $($posted on Canvas$).$ The table extends over two pages.

Hint: when calculating the maximum moment and deflection for beam B$4$ you can use superposition $($calculate separately the effects from the uniform load and from the concentrated load and add them up$)$