Web Reinforcement Limits and Detailing for Shearwalls
ICONS
ΣA g = The sum of the cross-sectional areas of the
structural system elements working as a curtain parallel to the earthquake direction considered at any floor ΣA p = Sum of the plan areas of all floors of the building
f ctd = Design tensile strength of concrete
H cr = Curtain critical height
H w = Above the foundation or Total curtain height measured from the ground floor slab
l w = Plan length of the curtain or tie-beam curtain piece
V t = Section 4According Total seismic load acting on the building (base shear)
φ = Rebar diameter
7.6.3. Body Reinforcement Conditions
7.6.3.1 - The total cross-section area of the web reinforcements on both sides of the wall shall not be less than 0.0025 of the gross cross-section area of the curtain body remaining between the wall end regions for each of the longitudinal and transverse reinforcements . If H w / l w ≤ 2.0, the curtain body region will be considered as the whole section of the curtain. Longitudinal and transverse reinforcement spacing in the curtain body shall not be more than 250 mm ( Figure 7.11 ).
7.6.3.2 - 7.6.1.3 from Eq. (7.14) with the conditions in buildings where both supplied, each of the longitudinal and transverse reinforcement ratio total body 0002 'to be downloaded. However, in this case, the reinforcement range will not exceed 300 mm.
7.6.3.3 - Reinforcement nets on both sides of the curtain bodies, except for the end zones, shall be mutually connected with at least four special seismic crossties on each square meter curtain face. However , along the critical wall height defined in 7.6.2.2 , at least ten special seismic crossties will be used on each square meter wall face excluding the end zones. Diameter of crossties shall be at least equal to the diameter of horizontal reinforcement. However, the number of crossties per unit area can be increased by ϕ stem / crossover to reduce their diameter.
7.6.4. Arrangement of Body Reinforcement
The clamping of the body reinforcements will be provided in the wall end region. The curtain end zone will consist of wrapping reinforcement, closed stirrup and cross-tie reinforcements. In addition, horizontal body reinforcements with 135 degree hooked ends to the longitudinal reinforcement can be used as the curtain end zone wrapping reinforcement. Horizontal or vertical square (90 degree hook) can be made to ensure that the horizontal body reinforcements are clamped at the wall end regions. The distance between the ends or squares of the horizontal web reinforcement and the outer edge of the curtain shall not be greater than 150 mm. In cases where lapped splices are required to be made to horizontal web reinforcements on the curtain body, lap splices will be made as staggered along the length of the curtain body, overlap length 1.5l b90 degree hooks will be formed at the ends of the horizontal reinforcements attached to overlaps. If hooks are not used at the ends of the horizontal web reinforcements, these rebars will be arranged in such a way that they are inside the longitudinal web reinforcements, there will be at least six longitudinal web reinforcements along the lap joint, and the horizontal distance between the longitudinal web reinforcements in the lap joint zone will not exceed 200 mm ( Figure 7.11 ).
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