topic Re: Isolated foundations with Tie beams in Robot Structural Analysis Forum

Isolated foundations with Tie beams

TSOFA — Fri, 30 Aug 2024 13:49:14 GMT

Hi, it is really common here to design for industrial buildings isolated foundations that are connected with tie beam foundations as it is shown at the attached file. How can I design this type of foundation using Robot?

Thanks in advance

Sofia

Re: Isolated foundations with Tie beams

Simau — Fri, 30 Aug 2024 15:35:15 GMT

Hi @TSOFA

Do you have the complete model or just the reactions

Re: Isolated foundations with Tie beams

TSOFA — Fri, 30 Aug 2024 15:39:26 GMT

The whole model, it is attached bellow

link: https://we.tl/t-bszTcy814E

Re: Isolated foundations with Tie beams

Simau — Fri, 30 Aug 2024 16:20:13 GMT

Personnally i will not bother with these ties. They are constructif elements that retain the soil at both sides. More over it's conservatif.

To design your foudations use directly the model you attached

Re: Isolated foundations with Tie beams

TSOFA — Mon, 02 Sep 2024 08:53:42 GMT

The problem is that we want to take tie beam in to account in order to minimize the dimensions of foundation. The foundation that is designed from Robot without tie beams is huge.

Re: Isolated foundations with Tie beams

Simau — Mon, 02 Sep 2024 11:48:22 GMT

Hi @TSOFA

You may add the ties with the existing offset using rigid links.

Model attached

Let us know the gain brought by the ties

Re: Isolated foundations with Tie beams

TSOFA — Mon, 02 Sep 2024 14:40:44 GMT

At the model that you attached, the tie beam doesn't have any support (like elastic ground), nor is a foundation designed. Finally, at my foreamentioned drawing, the tie beam is a T beam section.

My problem is how I will take in to account the reliefing of the foundation from the existing of the tie beam. So, my question is how we can model a combined foundation system with tie beam AND isolated foundation, which is a common practice to several european countries.

I found it strange, after 15 years that I use Robot, not to be able to design properly a simple foundation system like this. Softwares like Cype, which is a new software at the market and extremely cheaper ( the perpetual price is the one year rental of Robot) is able to do it. I am attaching a picture from cype software, in order to be clear what I need to design.

Re: Isolated foundations with Tie beams

Simau — Mon, 02 Sep 2024 18:35:02 GMT

You may add panels at the existing model.
It's more difficult to take into account the ties offset, and i think it's not so different if you assume that there is no ties offset.
In the model attached i tried with tie offset but to much time consuming. So i let you choose what you prefer.
Keep in mind that if you allow uplift in foundation elasticity parameter, you will not be able to run modal analysis

Re: Isolated foundations with Tie beams

TSOFA — Tue, 03 Sep 2024 09:04:55 GMT

So we still don't have a solution with isolated foundations that are connected with tie beams as the picture that I attached from a Cype model. Is this correct?

Re: Isolated foundations with Tie beams

Simau — Tue, 03 Sep 2024 10:23:43 GMT

So we still don't have a solution with isolated foundations that are connected with tie beams as the picture that I attached from a Cype model. Is this correct?

No, it's not correct.

I don't know what Cype can do in this particular case, waht i can say is with robot there is no ready-to-use solution.
The flexibility of robot allows you to model any structure, you just have to put the time it takes. I gave you a workaround from many other to solve your problem, it's up to you to ask and put the time it takes.
It's not so difficult to add panels as foundation to your actual structure. You will get all results as: soil stress, founadtion uplift, foundation reinforcement,....

Re: Isolated foundations with Tie beams

Simau — Tue, 03 Sep 2024 10:26:22 GMT

I'm curious to know what Cype can do in this case

Re: Isolated foundations with Tie beams

Simau — Tue, 03 Sep 2024 11:20:49 GMT

A small example

Re: Isolated foundations with Tie beams

TSOFA — Wed, 04 Sep 2024 07:40:21 GMT

If you see the attached picture at my message above, you can see what can cype model.

Re: Isolated foundations with Tie beams

TSOFA — Wed, 04 Sep 2024 07:44:36 GMT

Could you send me the model?
So the only way that Robot can model a simple foundation system like this is to use finite element analysis. As it is obvious, if we model the tie beams as plates, software will not give you the RC design of a RC beam and you will forced to do all the calcs by hand.

Re: Isolated foundations with Tie beams

Simau — Wed, 04 Sep 2024 13:45:14 GMT

It seems that you don't like any of my propositions, so why do you ask for the model if it doesn't fit your needs.

I suggest you using directly Cype instead.

Re: Isolated foundations with Tie beams

TSOFA — Thu, 05 Sep 2024 10:19:05 GMT

What I don't like is that Autodesk has abandoned the development of a software like Robot, which I as a user (and many many more colleagues) are supporting and invested our experience so many years on becoming expert users. It is fustrating for us to be forced to change our main desing software after almost 20years. Personally, I found really strange the software not to have developed something so common as this type of foundation, and I created the post in order to check if there is something new that I was not aware of. My intension was not to irritate you, but to point out that if there is not a solution for a problem like this, Autodesk should do something.

Re: Isolated foundations with Tie beams

Simau — Thu, 05 Sep 2024 11:17:36 GMT

You are mixing two subjects that have nothing in common.

If you have any comments on Robot open another thread with a request to development team.

Re: Isolated foundations with Tie beams

TSOFA — Fri, 06 Sep 2024 07:25:38 GMT

I did it, you can see it at "Robot Structural Analysis Ideas" forum. As I explained, I did the current post in order to verify if there is an other way, that I am not aware of, to design the foundation.