portal frame fixity restraints used on analysis software

[timmy555]

HI

I was wondering if anyone could help with verifying the typical fixity / restraints that would be used in comp analysis for a portal frame attached image? I have highlighted the areas questioned.

Any assistance will be appreciated. Thank you.

 

[Settingsun]

How thick are the connection plates? Do any of them need to be rigid for stability (ie any bracing)?

 

[HTURKAK]

Pls provide more info: East-West framings, vertical and horizontal bracings etc...to get better responds..

 

[timmy555]

Thanks for the reply steve
Ive attached a clearer image for you.
Basically there is a 16mm plate base with 4m20 bolts plate CFW around on the LHS with 57x57 EA bracing also welded near the base.
RHS the 150UC30 is welded to a 16mm base plate with 4-M20bolts over a 530UB92
Basically we want to determine if the protal can support any additional loads for suspended ceiling and HVAC units ?
Attached is a clearer section detail.
Appreciate your help again

 

[timmy555]

Pls provide more info: East-West framings, vertical and horizontal bracings etc...to get better responds..

This is the only other section plans I have that's useful...

 

[engineering_patrol]

SUre, you can google for 2d frame analyssi software-static edition in order to solve this frame with just few clicks.

 

[timmy555]

Thanks for that, i have analysis tool for this, I just want to make sure i have the correct fixity / restraints selected.

 

[HTURKAK]

Hi timmy555 ,

I do not want to disappoint you but apparently non of the connections satisfy the rigid connection requirements..Moreover, there are no VB,s and Horizontal bracings .. Not sure how the stability of structure in East-West direction is satisfied but i think mostly by masonry wall and existing structure connection and horizontal bracing requirement for roof level with purlins and roof cladding , first floor with composite slab ?

The steel sections implies EC-3 is the code..

I will suggest you to perform analysis with half fixity concept.

The following docs. will be useful to understand the method..

https://people.fsv.cvut.cz/~wald/CESTRUCO/CESTRUCO_TEXT_MATERIAL/04-STRUCTURAL_MODELLING_W.PDF

https://people.fsv.cvut.cz/~wald/CESTRUCO/CESTRUCO_TEXT_MATERIAL/05-simple_connections_w.pdf

https://people.fsv.cvut.cz/~wald/CESTRUCO/CESTRUCO_TEXT_MATERIAL/06-MOMENT_CONNECTIONS_W.PDF

 

[timmy555]

Thanks for confirming Hturkak appreciate it

not a problem Ill have a look over the material recommended thanks

re. the structure yes first floor is suspended slab and the short side wall and one long side has double masonry. roof is just timber purlins @ 600

thanks again.

 

[human909]

As a general rule, for your 'typical' portal frame structure the costs of rigid foundations and rigid connections to the foundations exceed the costs of pinned connections with a stiffer portal frame.

Recently though I've been designing some particularly slender portal frame where the height is 4-5 times the width. Rigid foundation connections here make sense because your can easily introduce a ground beam connection the adjacent columns and closing the portal square with your foundation. The extra concrete and more is needed anyway due to stability requirements under wind and seismic loads.

 

[timmy555]

Thank you all