Modelling perimeter strip footing with pad footings at opening

DMBUDD
DMBUDD Altair Community Member

Hello,

This is my first time attempting to utilize S-Foundation in practice and I'm finding it rather difficult to actually get beyond establishing the grids.

I am trying to model a perimeter strip footing around a building. There are a couple significant openings along the face of the building where pad footings will be required for additional capacity.

Q: What is the best way to approach the modelling of this?

I have attempted to use a "wall footing" around the perimeter and this is satisfactory. However, when I go to add "isolated footing" at the opening locations the program states that there is overlap. This makes sense, but I'm wondering how to increase the width of the footing at the opening locations.

Q: Do I need to go to individual locations and edit the pad type?

See attached for a simple sketch of the paper model.

I have gone through many of the youtube tutorials and, unfortunately, they are very general and do not explain this very basic and common scenario. I believe that if I could gain some insight into modelling this scenario I would have better use of the program in practice and consider extending my subscription.

Q: Is there a way to get a brief consult with Altair Technical Support to help with this?

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Best Answers

  • Alejandro_López_Av
    Alejandro_López_Av
    Altair Employee
    Answer ✓

    Hello, DMBUDD,

    Additionally, when defining a wall footing, you can press the Tab key on your keyboard to activate the Pedestal mode, connecting your walls with the equivalent of an isolated footing.

  • Alejandro_López_Av
    Alejandro_López_Av
    Altair Employee
    Answer ✓

    If you are not very fond of the ticket idea, we can schedule the Teams call directly, we'll be happy to help.

Answers

  • Tayen_Aguilar_57
    Tayen_Aguilar_57
    Altair Employee

    Hi, thank you for your message.

    From a very general point of view, you might benefit from a Multi-Strap foundation, I'm not sure if you have seen the following video explaining that process:

    https://youtu.be/lrM8kk5_g9s?si=RabiZtqcXgV3ZNFs

    We would be glad to take a deeper look at your issue if you could share your model and the questions you have on the following link,

    https://community.altair.com/categories/support

    We could arrange a meeting to better understand and guide you through modeling and analyzing your foundations.

    Best regards,

    Tayen Aguilar

    Altair Support

  • Alejandro_López_Av
    Alejandro_López_Av
    Altair Employee
    Answer ✓

    Hello, DMBUDD,

    Additionally, when defining a wall footing, you can press the Tab key on your keyboard to activate the Pedestal mode, connecting your walls with the equivalent of an isolated footing.

  • DMBUDD
    DMBUDD Altair Community Member

    Wow! Thanks for the responses. I think the "Tab" for Pedestal Mode is what I need. I will try today.

    Q: Are you able to define line loads on a wall footing? It is just showing up as a point load at the nodes/joints. Typically I'm dropping roof loads from wall segments using a line load (lb/ft) onto the strip footing. If my nodes are set up per ft, then potentially I could just use the point load method. But it seems like applying lb/ft would be the common application here.

  • DMBUDD
    DMBUDD Altair Community Member

    I have to admit. This program is really difficult to navigate through the dialog boxes and understand what the changes are affecting. Why under the "Define Pads/Pile Caps" dialog do I have to go through Wall Strip options (which direction is the width? which direction is extrusion?) one by one, waiting for each change to load in the program? And then switch to Pedestal Pads and do a similar process? Very frustrating. And geometry changes then make my nodes disconnect, so I need to draw it again? I'm just not sure how this program is supposed to save time if it takes me 60minutes to even define everything before adding loads.

    Please help.

  • DMBUDD
    DMBUDD Altair Community Member

    Update: It's a little bit more intuitive using the Object>Selection tool box instead of the dialog box, but it's still slow to update. I guess defining these at the start would have been the better move.

  • Hi again, DMBUDD,

    S-FOUNDATION is a program developed with the intention of working with the reactions once an analysis is performed. Usually, the user would model the superstructure in other programs (S-FRAME, for example) and then pass the results to S-FOUNDATION to model the substructure.

    We strongly recommend opening a case, following the link my colleague Tayen shared before, so we can have a better follow-up of your case. Additionally, we want to bring up the option to schedule a meeting so we can have more direct communication, via the ticket mentioned before. We'll be happy to respond to all your inquiries through this channel.

  • Alejandro_López_Av
    Alejandro_López_Av
    Altair Employee
    Answer ✓

    If you are not very fond of the ticket idea, we can schedule the Teams call directly, we'll be happy to help.

  • DMBUDD
    DMBUDD Altair Community Member

    Hi Alejandro_Lopez_Av and Tayen_Aguilar_57:

    Thanks for the help and suggestions. I have made a case and sent my model with a couple PDFs for context. I appreciate the support.