Nội dung text 34 RCD - Shear and Torsion.pdf
422.5.6. Vc for Non-prestressed Members with Axial Force 422.5.6.1. For non-prestressed members without axial force, Vc shall be calculated by: Vc = 0.17 (1 + Nu 14Ag ) λ√fc ′bwd unless a more detailed calculation is made in accordance with Table 422.5.6.1., where Nu is positive for compression. Table 422.5.6.1. Detailed Method for Calculating Vc Vc Least of (a), (b) (a) (0.16λ√fc ′ + 17ρw Vud Mu − Nu 4h − d 8 ) bwd [1] Not applicable if Mu − Nu ( 4h − d 8 ) ≤ 0 (b) 0.29λ√fc ′bwd√1+ 0.29Nu Ag [1] Mu occurs simultaneously with Vu at the section considered. 422.5.7. Vc for Non-prestressed Members with Significant Axial Tension 422.5.7.1. For non-prestressed members without axial force, Vc shall be calculated by: Vc = 0.17 (1+ Nu 3.5Ag ) λ√fc ′bwd where Nu is negative for tension and Vc cannot be less than zero. 422.5.10. One-way Shear Reinforcement. 422.5.10.1. At each section where Vu ≥ ∅Vc , transverse reinforcements shall be given such that the equation is satisfied. Vs ≥ Vu ∅ − Vc 422.5.10.5.3. Vs for shear reinforcement in Section 422.5.10.5.1. shall be calculated by: Vs = Avfytd s Where s is the spiral pitch or the longitudinal spacing of the shear reinforcement. 422.10.5.4. Vs for shear reinforcement in Section 422.5.10.5.2. (inclined stirrups) shall be calculated by: Vs = Avfyt(sin α + cos α)d s Where α is the angle between the inclined stirrups and the longitudinal axis of the member, and s is measured parallel to the longitudinal reinforcement. Whenever the data are unavailable for exact value, the effective depth must not be taken less than 0.8 times the height of a beam. In circular sections, the effective depth must be taken as 0.8 times the diameter (or the shear area bwd as 0.8D 2 ) For the ultimate capacity, Vu ≤ ∅Vn where ∅ is 0.75 in newer codes (2010 and 2015) and 0.85 in older codes.
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