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Table 1 Special provisions for shear walls with boundary elements.

From: Seismic Performance of Special Structural Walls Using Overlapping Hoops Instead of Closed Hoops

  ACI318-14, KBC 2016 (special structural wall) AIJ2010 (RC wall with boundary columns) EN1998-1:2004(E) (ductile wall)
l cr Max{lw, Mu/4Vu} or more Max{2 × smaller of lc and b, 1.5 × greater of lc and b} at the upper and lower ends of the wall Max[lw, hw/6] or more
Geometrical constraints lc≥ greater of c − 0.1lw and c/2 bw ≥  hs/15 for lc < 2bw, 0.2lw
bw ≥  hs/10 for lc > 2bw, 0.2lw
bw ≥ 200 mm
s Min{1/3b, 6dbL, 100 + [(350 − hx)/3]} or less 100 mm or less Min{b0/2, 175, 8dbL} or less for DCM
Min{b0/3, 125, 6dbL} or less for DCH
Amount of transverse reinforcement Greater of \(0.09\frac{{f_{c}^{{\prime }} }}{{f_{yt} }}\) and \(0.3\left( {\frac{{A_{g} }}{{A_{ch} }} - 1} \right)\frac{{f_{c}^{{\prime }} }}{{f_{yt} }}\) 0.002 or more \(\omega_{wd}\)  ≥ 0.08 for DCM
\(\omega_{wd}\)  ≥ 0.12 for DCH
  1. Ach: cross-sectional area of a member measured to the outside edges of transverse reinforcement; Ag: gross area of concrete section; b: width of confined parts of a wall section; b0: width of confined core in the boundary element of a wall; bw: thickness of confined parts of a wall section; c: the largest neutral axis depth; dbL: longitudinal bar diameter; \(f_{c}^{{\prime }}\): compressive strength of concrete; fyt: yield strength of transverse reinforcement; hs: clear story height; hw: height of wall; hx: maximum center-to-center spacing of longitudinal bars laterally supported by corners of crossties or hoop legs; lc: length of confined parts of a wall section; lw: length of cross-section of wall; \(\omega_{wd}\): volumetric ratio of confining hoops within the boundary elements; Mu: factored moment at section; Vu: maximum factored shear stress; s: center-to-center spacing of transverse reinforcement; lcr: length of critical region; DCM: medium ductility; DCH: high ductility.