(b) Precast in-plant
(c) Precast on-site including tilt-up
|Wall type||Minimum thickness h|
|Bearing||Greater of:||4 in.||(a)|
|1/25 the lesser of unsupported length and unsupported height||(b)|
|Nonbearing||Greater of:||4 in.||(c)|
|1/30 the lesser of unsupported length and unsupported height||(d)|
|Exterior basement and foundation||7.5 in.||(e)|
|Walls braced top and bottom against lateral translation and:|
|(a) Restrained against rotation at one or both ends (top, bottom, or both)||0.8|
|(b) Unrestrained against rotation at both ends||1.0|
|Walls not braced against lateral translation||2.0|
|Vn = Vc+ Vs||(220.127.116.11)|
|Calculation option||Axial force||Vc|
|Detailed||Tension or compression||Lesser of:||(d)|
Equation shall not apply if (Mu/Vu— ℓw/2) is negative.
|Wall type||Type of nonprestressed reinforcement||Bar/wire size||fy, psi||Minimum longitudinal, ρℓ||Minimum transverse, ρt|
|Cast-in-place||Deformed bars||≤ No. 5||≥ 60,000||0.0012||0.0020|
|> No. 5||Any||0.0015||0.0025|
|Welded-wire reinforcement||≤ W31 or D31||Any||0.0012||0.0020|
|Precast||Deformed bars or welded-wire reinforcement||Any||Any||0.0010||0.0010|
In one-way precast, prestressed walls not wider than 12 ft and not mechanically connected to cause restraint in the transverse tion, the minimum reinforcement requirement in the direction normal to the flexural reinforcement need not be satisfied.
(a) ρℓ shall be at least the greater of the value calculated by Eq. (11.6.2) and 0.0025, but need not exceed ρt required by 18.104.22.168.
|ρ ℓ ≥ 0.0025 + 0.5(2.5 — hw/ℓw)(ρt — 0.0025)||(11.6.2)|
(b) ρt shall be at least 0.0025
(a) One layer consisting of at least one-half and not exceeding two-thirds of total reinforcement required for each direction shall be placed at least 2 in., but not exceeding h/3, from the exterior surface.
(b) The other layer consisting of the balance of required reinforcement in that direction, shall be placed at least 3/4 in., but not greater than h/3, from the interior surface.
(a) Cross section is constant over the height of the wall
(b) Wall is tension-controlled for out-of-plane moment effect
(c) ϕMn is at least Mcr, where Mcr is calculated using fr as provided in 19.2.3
(d) Pu at the midheight section does not exceed 0.06f'cAg
(e) Calculated out-of-plane deflection due to service loads, Δs, including PΔ effects, does not exceed ℓc/150
(b) The edges of the wall panel
(a) By iterative calculation using
|Mu = Mua+ PuΔu||(22.214.171.124a)|
Δu shall be calculated by:
where Icr shall be calculated by:
and the value of Es/Ec shall be at least 6.
(b) By direct calculation using: