Platform Frame Construction Example

For the structure shown, find:

1. An exploded axon of the building, showing a uniform, 30 psf wind load acting on the south stud wall. Determine and label the uniform wind load acting on the roof diaphragm.
2. Draw a plan of the roof diaphragm, showing the wind load acting on it and the stud wall reaction. What is the magnitude of this reaction?
3. Draw defected shape, shear and moment diagrams for the roof. Determine the location and magnitude of the maximum shear force and moment.
4. Draw a FBD showing the couple associated with the maximum moment. Determine the magnitude of the forces. Is one top plate strong enough to safely carry this force in tension?
5. If the plywood roof is nailed to the top plates on wall A with 6d nails which can safely resist (in no. 2 doug fir) 63 Ibs each, how many nails are required to resist the total diaphragm shear reaction? What is the associated nail spacing?

Solution