Wood Shear Wall Unit Shear and Holdown (SDPWS / ASD)

The unit shear v = V/b checked against the SDPWS nailing schedule, and the net holdown tension T = (V h - 0.6 W b/2)/b once the story shear tries to overturn the wall and only 0.6 times the tributary dead load resists it (the ASD combination). An 8 ft wall taking 8 kip at 10 ft with 3,000 lb of dead load runs 1,000 plf and a 9.1 kip holdown; load the wall to 20,000 lb and gravity cuts the holdown to 4.0 kip, and past the balance point the holdown clamps to zero. Segmented wall; sill anchorage and chord bearing are separate. A design aid, not a substitute for the engineer of record's stamped lateral design.

v = V / b; Mot = V h; Mr = 0.6 W (b/2); T = max((Mot - Mr) / b, 0).

The AWC SDPWS segmented shear-wall model with the ASCE 7 / IBC 0.6D allowable-stress overturning check, as compiled in the AWC/APA wood-frame shear-wall design guides, by name.

AWC SDPWS is viewable free of charge through AWC's online reader; the unit-shear and overturning-couple arithmetic is public.

Estimate. AHJ and licensed professional govern.

Field names used by the API: v_lb, b_ft, h_ft, w_lb, v_plf, mot_ftlb, mr_ftlb, t_lb

• 0.6D ASD combination the resisting dead load is factored 0.6 per the ASD 0.6D + 0.7E combination; where wind governs, use the wind combination's factorsASCE 7 §2.4 / IBC
• Segmented wall a single fully sheathed segment with the holdown at its end; perforated and force-transfer-around-openings walls distribute differentlyAWC SDPWS §4.3
• Companion checks separate sill anchor-bolt shear, compression-chord bearing, and the sheathing nailing selection are separate checksAWC/APA design guides