shearwall boundary element

[yexx0022]

Hi:

For seismic design, ACI requires boundary elements when the stress exceeding 0.2f'c.

If this is one piece wall, the boundary element location is at each end. If this is a T or box type lay out, do you consider this provision apply to the intersection of perpendicular walls?

I would think this applies. Any opnion on this?

Thanks.

 

[DST148]

ACI 318-05 Section 21.7.6.3 - Boundary Elements are required at boundaries and edges around openings of structural walls where the maximum extreme fiber compressive stress exceeds 0.2f'c. For walls with flanges, an effective flange width as defined in 21.7.5.2 shall be used for stress calculations.

If the stresses exceeds the limit even after accounting for the area of the flanges, the boundary element shall include the effective flange width in compression and shall extend at least 12 inches into the web. See 21.7.6.4(b)