Anonymous
  • Good comments and questions. It does appear we are being stricter than necessary in the spacing limit of the ties, as we missed the exception provided in 21.9.6.4(c). Many thanks for catching this. We will update this promptly.

    Concerning uniform reinforcing vs. clustered reinforcing in the boundaries, the axial flexural calculations consider the exact location of all reinforcing bars. So the strength calculations will be accurate regardless of how the bars are arranged.

    Concerning the out-of-plane effects, this module does not consider amplification for slenderness, as the column design module does. P-Delta effects are accounted for in the wall design as long as the RAM Frame analysis was run with this consideration. But there is no additional force or load amplification applied to walls in consideration of slenderness. For walls in which out-of-plane slenderness is a concern, some additional calculations outside of the module are necessary. The custom load combination tool may be of some use here as this allows you to scale up the gravity loads by any factor you wish.

  • I have two questions please.

    1- The interaction diagram is generated based on a uniform distribution of reinforcement. What if the reinforcement of the boundary element is different??

    2- Where is the effect of buckling in the weak inertia? by example ULS cases have zero moments while these should be amplified identically as for columns design....

  • Nice example.  One small comment is on the spacing of transverse reinforcement in the boundary zone.  ACI 318 §21.9.6.4(c) modifies 21.6.4.3(a) such that the spacing shall be one-third of the least dimension of the boundary element in lieu of one-fourth (required in §21.6.4.3(a) for frame columns).

    Thus, the minimum spacing could be 12/3 = 4"