Shear Wall Required and Design Strength
Wall required strengths are calculated automatically.
Wall design strengths are calculated automatically.
Ag = gross area of concrete section, in2
Av = area of shear reinforcement within spacing s, in.2
D = dead load
E = earthquake load
fc' = specified compressive strength of concrete, psi
fyt = specified yield strength of transverse reinforcement, psi
L = live load
Lr = roof live load
Mn = nominal flexural strength at section, in.-lb
Mu = factored moment at section, in.-lb
Pn = nominal axial compressive strength of member, lb
Pu = factored axial force; to be taken as positive for compression and negative for tension, lb
R = rain load
S = snow load
U = strength of a member or cross section required to resist factored loads or related internal moments and forces in such combinations as stipulated in ACI 318-19
Vn = nominal shear strength, lb
Vu = factored shear force at section, lb
W = wind load
ϕ = strength reduction factor
Required strength is calculated in accordance with the factored load combinations in Load Factors and Combinations title.
Reinforced concrete walls with rectangular, I, T, L, U or C crossection are modeled with finite elements (shells) containing degrees of freedom for both in-plane and out-of-plane displacements. The resultant of the finite element joint forces are obtained as equivalent internal force (Mu, Pu) at the cross-section gravity center, based on shear wall required strength and design strenth calculations.
The wall shear design is applied leg by leg for each of the design load combination. The factored shear force, Vu of the leg is determined and compared with design shear strength ϕVn.
Design strength at all sections should be satisfy all conditions given below;
ϕPn ≥ Pu
ϕMn ≥ Mu
ϕVn ≥ Vu
Strength reduction factors ϕ is determined according to using ACI Table 21.2.2. Interaction between load effects is considered.
Pn and Mn is calculated in accordance with Axial strength or Combined Flexural and Axial Strength title.