2001 ASD Supplements - unprotected PDF - American Wood Council

SW-26APPENDICESA.1 Design ExampleBasic DesignWood structural panel diaphragms and shear walls inone-story building seismic and wind loadings. 25 psf roofdesign snow loadGiven:In Figure A.1, building dimensions and openings asshown. Exterior walls consist of light-framed woodsheathedshear walls. All framing members are hem-firlumber unless noted otherwise. The floor is framed with11-7/8-inch I-joists and interior post-and-beam system.Interior posts are supported by pad footing and exteriorwalls are supported by continuous concrete wall footings.Determine:1. Seismic load and wind load on roof diaphragmalong each direction (determined in another analysis).2. Design unit shear in roof diaphragm along each direction.3. Roof structural panel layout and fastener schedule.4. Calculate chord forces.5. Connections between roof diaphragm and walls.6. Diaphragm deflection (N-S direction only).7. Shear in shear walls and shear panel fastener schedule(East and West walls only).8. Drag strut forces and drag strut connections (Eastand West walls only).9. Hold-down forces and hold-down connections (Eastand West walls only).Figure A.1 Building Plan View andTypical Section of ExteriorWallsb = 110'Plan ViewN45'45'20' x 20' overhead doorTypical Section of Exterior Walls2'24'L = 240'Roof diaphragm2X8 Hem-fir stud wall15/32" Sheathing, Exposure I20' high windows70'40'Step 1.Seismic Load and Wind Load on Roof Diaphragm Along EachDirectionDetailed seismic force and wind force calculations arebeyond the scope of this Supplement.For this example, assume the following:V seismic N-SV seismic E-WV wind N-S= 53,768 lb.= 37,752 lb.= 61,519 lb.V wind E-W= 28,196 lb.APA – The Engineered Wood Association