S-Concrete estimated "d" as 0.8*Lw. Shear wall calculation.

Aleksei Lopato
Aleksei Lopato Altair Community Member
edited September 2023 in Community Q&A

To whom it might concern.

There is some problem that I couldn't find how to fix. For the concrete wall, the software S-Concrete estimated "d" as 0.8*Lw, but I couldn't find any requirements in ACI 318-19 saying what we have to do it. The question is why the program decided to use this method to determine "d", and how I can reject to use 0.8 factor. I found a way to reject this factor for beam calculation but couldn't find how to do it for the wall calculation. Please see the picture in the attachment.

Thank you.

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Answers

  • Andres Chavez
    Andres Chavez New Altair Community Member
    edited September 2023

    Hello Aleksei,

     

    Thanks for posting on the Altair Community forums. My name is Andrés and I am part of Altair's Technical Support. We will be glad to respond to your request.

    We appreciate the screenshot and elaboration. In this case, it is worth clarifying that S-CONCRETE calculates the effective depth through strain compatibility analysis of the section. This means that the program will take the effective depth 'd' as the distance from the extreme compression fiber to the location of the resultant tensile force in the reinforcement, which means that the actual stress in each bar will be accounted for, regardless if the bar has yielded or not. For the case when some of the tension steel is not at yield, the location of the resultant tension force does not coincide with the location of the centroid of tension steel.

    With that said, S-CONCRETE adopts a lower limit of 0.8h for the effective depth used for shear calculations, "h" being the overall section dimension measured in the direction of the shear force. The General Rule (d >=0.8h) is applied to all member types and building standards with minor exceptions, which can be reviewed in more depth in S-CONCRETE's Internal Help System. Please refer to the excerpt of the ‘Shear and Torsion - Shear Resistance’ attached to this message.

    For beams, the user can specify if this can be ignored, as you pointed out, but that same option is currently unavailable for columns and walls.

    We hope this information helps clear things up. Please share your thoughts with us; we look forward to hearing from you again. We'll remain attentive to your comments.

     

     

    Kind regards,

     

    Andrés Chávez Burgos

    AEC Solutions Engineer

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