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Section 2305 General Design Requirements for Lateral Force-Resisting Systems
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Structures using wood-frame shear walls or wood-frame diaphragms to resist wind, seismic or other lateral loads shall be designed and constructed in accordance with AWC SDPWS and the applicable provisions of Sections 2305, 2306 and 2307.
The deflection of wood-frame diaphragms shall be determined in accordance with AWC SDPWS. The deflection (Δdia) of a blocked wood structural panel diaphragm uniformly fastened throughout with staples is permitted to be calculated in accordance with Equation 23-1. If not uniformly fastened, the constant 0.188 (For SI: 1/1627) in the third term shall be modified by an approved method.
For SI: Δdia = 0.052vL3/EAW + vL/4Gt + Len/1627 + Σ(xΔc)/2W
Δdia = 5vL3/8EAW + vL/4Gt + 0.188Len + Σ(xΔc)/2W
(Equation 23-1)
For SI: Δdia = 0.052vL3/EAW + vL/4Gt + Len/1627 + Σ(xΔc)/2W
where: | ||
A | = | Area of chord cross section, in square inches (mm2). |
E | = | Modulus of elasticity of diaphragm chords, in pounds per square inch (N/mm2). |
en | = | Staple slip, in inches (mm) [see Table 2305.2(1)]. |
Gt | = | Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2)]. |
L | = | Diaphragm length (dimension perpendicular to the direction of the applied load), in feet (mm). |
v | = | Induced unit shear in pounds per linear foot (plf) (N/mm). |
W | = | Diaphragm width [in the direction of applied force, in feet (mm)]. |
x | = | Distance from chord splice to nearest support, in feet (mm). |
Δc | = | Diaphragm chord splice slip at the induced unit shear, in inches (mm). |
Δdia | = | Maximum mid-span diaphragm deflection determined by elastic analysis, in inches (mm). |
LOAD PER FASTENERb (pounds) | FASTENER DESIGNATIONS |
14-Ga staple × 2 inches long | |
60 | 0.011 |
80 | 0.018 |
100 | 0.028 |
120 | 0.04 |
140 | 0.053 |
160 | 0.068 |
For SI: 1 inch = 25.4 mm, 1 foot = 304.8 mm, 1 pound = 4.448 N.
PANEL TYPE | SPAN RATING | VALUES OF Gt (lb/in. panel depth or width) | |||||||
Structural Sheathing | Structural I | ||||||||
Plywood | OSB | Plywood | OSB | ||||||
3-ply | 4-ply | 5-plya | 3-ply | 4-ply | 5-plya | ||||
Sheathing | 24/0 | 25,000 | 32,500 | 37,500 | 77,500 | 32,500 | 42,500 | 41,500 | 77,500 |
24/16 | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 | |
32/16 | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 | |
40/20 | 28,500 | 37,000 | 43,000 | 88,500 | 37,000 | 48,000 | 47,500 | 88,500 | |
48/24 | 31,000 | 40,500 | 46,500 | 96,000 | 40,500 | 52,500 | 51,000 | 96,000 | |
Single Floor | 16 o.c. | 27,000 | 35,000 | 40,500 | 83,500 | 35,000 | 45,500 | 44,500 | 83,500 |
20 o.c. | 28,000 | 36,500 | 42,000 | 87,000 | 36,500 | 47,500 | 46,000 | 87,000 | |
24 o.c. | 30,000 | 39,000 | 45,000 | 93,000 | 39,000 | 50,500 | 49,500 | 93,000 | |
32 o.c. | 36,000 | 47,000 | 54,000 | 110,000 | 47,000 | 61,000 | 59,500 | 110,000 | |
48 o.c. | 50,500 | 65,500 | 76,000 | 155,000 | 65,500 | 85,000 | 83,500 | 155,000 |
Structural Sheathing | Structural I | ||||||
Thickness (in.) | A-A, A-C | Marine | All Other Grades | A-A, A-C | Marine | All Other Grades | |
Sanded Plywood | 1/4 | 24,000 | 31,000 | 24,000 | 31,000 | 31,000 | 31,000 |
11/32 | 25,500 | 33,000 | 25,500 | 33,000 | 33,000 | 33,000 | |
3/8 | 26,000 | 34,000 | 26,000 | 34,000 | 34,000 | 34,000 | |
15/32 | 38,000 | 49,500 | 38,000 | 49,500 | 49,500 | 49,500 | |
1/2 | 38,500 | 50,000 | 38,500 | 50,000 | 50,000 | 50,000 | |
19/32 | 49,000 | 63,500 | 49,000 | 63,500 | 63,500 | 63,500 | |
5/8 | 49,500 | 64,500 | 49,500 | 64,500 | 64,500 | 64,500 | |
23/32 | 50,500 | 65,500 | 50,500 | 65,500 | 65,500 | 65,500 | |
3/4 | 51,000 | 66,500 | 51,000 | 66,500 | 66,500 | 66,500 | |
7/8 | 52,500 | 68,500 | 52,500 | 68,500 | 68,500 | 68,500 | |
1 | 73,500 | 95,500 | 73,500 | 95,500 | 95,500 | 95,500 | |
11/8 | 75,000 | 97,500 | 75,000 | 97,500 | 97,500 | 97,500 |
The deflection of wood-frame shear walls shall be determined in accordance with AWC SDPWS. The deflection (Δsw) of a blocked wood structural panel shear wall uniformly fastened throughout with staples is permitted to be calculated in accordance with Equation 23-2.
Δsw = 8vh3/EAb + vh/4Gt + 0.75hen + dah/b
(Equation 23-2)

where: | ||
A | = | Area of end-post cross section in square inches (mm2). |
b | = | Shear wall length, in feet (mm). |
da | = | Total vertical elongation of wall anchorage system (such as fastener slip, device elongation, rod elongation) at the induced unit shear in the shear wall (v). |
E | = | Modulus of elasticity of end posts, in pounds per square inch (N/mm2). |
en | = | Staple slip, in inches (mm) [see Table 2305.2(1)]. |
Gt | = | Panel rigidity through the thickness, in pounds per inch (N/mm) of panel width or depth [see Table 2305.2(2)]. |
h | = | Shear wall height, in feet (mm). |
v | = | Induced unit shear, in pounds per linear foot (N/mm). |
Δsw | = | Maximum shear wall deflection determined by elastic analysis, in inches (mm). |
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