• Transverse reinforcement detailing is applied automatically in accordance with ACI 11.7

  • Transverse reinforcement detailing is applied according to ACI Chapter 18 in special structural walls.


Notation

Acv = gross area of concrete section bounded by web thickness and length of section in the direction of shear force considered in the case of walls, and gross area of concrete section in the case of diaphrams. Gross area is total area of defined section minus area of any openings, in.2
Acw = area of concrete section of an individual pier, horizontal wall segment, or coupling beam resisting shear, in2.
fc' = specified compressive strength of concrete, psi
√fc = square root of specified compressive strength of concrete, psi
fy = specified yield strength of nonprestressed reinforcement, psi
h = overall thickness, height, or depth of member, in.
hw = height of entire wall from base to top, or clear height of wall segment or wall pier considered, in.
lw = length of entire wall, or length of wall segment or wall pier considered in direction of shear force, in.
s = center-to-center spacing of items, such as longitudinal reinforcement, transverse reinforcement, tendons, or anchors, in.
Vn = nominal shear strength, lb
Vu = factored shear force at section, lb
ϕ = strength reduction factor


According to ACI 11.7.3.1; maximum spacing of transverse reinforcement bars in shear walls is the lesser of 3h and 18 inches. If shear reinforcement required for in-plane strength, maximum s should be lw/5.

According to ACI 11.7.4.1; logitudinal reinforcement should be laterally supported bu transverse reinforcement if the following two conditions are satified;

  • Ast > 0.01Ag

  • longitudinal reinforcement is required


Earthquake Resistant Structures

Special structural walls

According to ACI 18.10.4.3, shear walls should have distributed shear reinforcement in two orthogonal directions in the plane of the wall. If hw/lw ≤ 2.0 , reinforcement ratio ρl should be at least the reinforcement ratio ρt.