modelling slab fold in etabs

[4dmodeller]

Hi all,

Just wondering if anyone can recommend how to draw a slab fold/ step (1 m deep) between lower ground floor and upper ground floor in etabs?

 

[chekre]

Create a reference plane at the required elevation and use the spandrel opton to connect the 2 slabs.

 

[4dmodeller]

Chekre,

I never really get the use of spandrel. I tend to like the answer (e.g. bending moment) i get better when i use a frame element e.g. for door opening. I have tried meshing the spandrel. but to get a realistic looking answer i have to label each spandrel something different all the way through the length of it. Any thoughts on how to fix that? have you come across it?

Just not sure how it fares as a slab fold. Also, i do not want to design it as a beam, simply a slab fold.

 

[chekre]

Right. Chexk the autolabeling of spandrel it will economise a lot of time.
Personally i model the slab folds as beam spanning between support since there will be no continuuty between the 2 levels except by this member.
Can u tell me how are u planning to design it as a slab fold ? U can also check the stresses in the spandrel.and design it the way you judge corrext

 

[4dmodeller]

Chekre, where is this auto labeling feature for spandrel?
it will be designed with program such as rapt. Personally, i would just ignore the stiffness contribution from the slab fold in terms of strength and detail the slab fold to allow bar continuity and cracking at corners.

 

[4dmodeller]

Chekre,
I don't really get how to make use of stresses in the spandrel...how does that help me design the slab fold?
This is the same as a deep beam in etabs...looking at stresses can help me visualise if the compression and tension is in the right location..but i do not know how to design purely from stresses output from etabs.

Please guide?

 

[chekre]

The autolabeling figures when u select the wall definituon and wants to draw it. Have a look there. U will find it.
As.for the slab mold, display the forces on your spandrel (f11 f22 f12 m11 m22 and m12) and design ur drop accordingly.
As i told u personally i prefer to analyse a drop of 1 m as a beam carrying 2 levels and not use the details which insure a continuity since i dont believe that i will unless the drop is equal or less than the slab thickness that u are dealing with

 

[4dmodeller]

Chekre,

I still cant find an autolabelling tool for spandrel..can you show me where? like assign-> shell-> where? where can i autolabel?

i dont really know how to use stresses for design...as its not equivalent to Ultimate limit state design where concrete is assume cracked..and all tension is localised in the rebar etc...

can you give an example?

 

[chekre]

4d modeler,
u can find the autolabeling thing when u pick the spandrel option and begin to draw.
i dont etabs on the computer i am using. once i am home i will screenshot it for u.
regarding the slab mold and since u will design it as s slab, use the forces in the spandrel m11 m22 m12 and the shears to evaluate the load transfer and how u should reinforce your element (have a look at the local axes to check which moment, shear, axial) to consider.

 

[4dmodeller]

Chekre, please screenshot for me . thank you.

 

[chekre]

which version are u using ?

 

[4dmodeller]

15.0

 

[chekre]

Sorry for the late message. Attached a screenshot of the auto labeling of the spandrel.