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Slab reinforcement calculation according to russian code

17 REPLIES 17
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Message 1 of 18
Ronald286
1192 Views, 17 Replies

Slab reinforcement calculation according to russian code

Hello,

when i try to calculate required reinforcement for slab according to russian code, Robot gives me a warning about SLS combinations, and says, that all loads applied as quasi-permanent. So, what kind of SLS i need to create to avoid this warning? Thank you.

17 REPLIES 17
Message 2 of 18
Rafal.Gaweda
in reply to: Ronald286

Ignore it.

EC base codes warning message displayed. Not relevant to snip code.



Rafal Gaweda
Message 3 of 18
Ronald286
in reply to: Rafal.Gaweda

Rafal, I made simple test.

I switched russian codes combinations, and i switched RC elements design according russian standarts. Than I defined a simple slab. I created two load types: DEAD load, and short-term load. I made two different calculations 1. for dead load i defined uniform load 1kN/m2, and for short-term load I defined 40kN/m2. 2. for dead load i defined 40kN/m2, for short-term load I defined 1kN/m2. In both calculations I created automatic combinations for ULS and SLS. After I calculated required reinforcement. For ULS and SLS i used SLS combinations. In both cases I got the same value of stiffness factors. So, as I understood, program doesn't recognize short-term loads and takes into account the creep of concrete for all types of loads. Any comments?

Message 4 of 18
Rafal.Gaweda
in reply to: Ronald286

I was promised to get answer for all your snip slab design related questions on Monday.



Rafal Gaweda
Message 5 of 18
Rafal.Gaweda
in reply to: Rafal.Gaweda

Necessary to change  next coefficient in dialog

For 1 case     40/(40+1)=0.98

 

ex6.jpg

 

For 2 case     1/(40+1)=0.02

 

ex2.jpg

 



Rafal Gaweda
Message 6 of 18
Ronald286
in reply to: Rafal.Gaweda

is it according to russian code? Seems little bit different. What would you suggest to do, if part of load on slab(load from heavy partitions) is long-term and distributed as uniform-linear load in exact position of the slab, and part of the load(live load) is short-term distributed as uniform load. So, I don't think, that duration factor would be suitable in this situation. 

Message 7 of 18
Rafal.Gaweda
in reply to: Ronald286

If the loads are same - the coefficient can be calculated in proportion to the value of loads, if the loads are different - then proportional to the maximum moment from each loads.



Rafal Gaweda
Message 8 of 18
Ronald286
in reply to: Rafal.Gaweda

Proportions for differenet areas(for every finite element) can be absolutely differenet, especially if you have point loads, linear loads, area loads with non-standart slab geometry. 

Message 9 of 18
Ronald286
in reply to: Ronald286

One more thing. I have a super easy slab. I have dead load and live load, I made SLS combination. I designed the slab for required reinforcement(all this according to russian code). I got the warning about SLS combinations and program said that calculations could be not correct(you said i can ignore this warning) After i want to see the crackings. But there are no cracks...why? Please, can you give any comment. I attached this super simple slab. Thank you!

Message 10 of 18
Rafal.Gaweda
in reply to: Ronald286

Workaround : 

 

slsw.jpg



Rafal Gaweda
Message 11 of 18
Ronald286
in reply to: Rafal.Gaweda

Rafal, can you give more detailed explanation why it doesn't work with analytical method? Is this problem going to be fixed in the nearest future? Our company have a big project in russia, and in the beginning we thought we will be able to design our buildings with RSA. But now it seems to me, program works not properly with russian standarts. At the moment we are thinking about purchasing other programs instead new licenses for Robot.

Message 12 of 18
Rafal.Gaweda
in reply to: Ronald286

 Is this problem going to be fixed in the nearest future?

 

Of course.

 



Rafal Gaweda
Message 13 of 18
Rafal.Gaweda
in reply to: Rafal.Gaweda

Already corrected in Service Pack 3 for ARSA 2014

http://usa.autodesk.com/adsk/servlet/ps/dl/item?siteID=123112&id=22436870&linkID=13140816



Rafal Gaweda
Message 14 of 18

Hi Rafal,

 

You are mentioning the ''duration factor of loads'' coefficient on your third message in ths thread.

Is this factor suppose to be this one mentioned in SNiP as φ1=1+Ml1/M1 ? If yes, is there a reason you are not using the ''1+..'' portion of the equation? Can you please explain?

 

 

Regarsd,

Charis

Message 15 of 18

In mentioned window Ml/M should be entered


Rafal Gaweda
Message 16 of 18

Hi,

Thanks for the swift reply.

Regards,

Charis

Message 17 of 18


@Rafal.Gaweda wrote:

Necessary to change  next coefficient in dialog

For 1 case     40/(40+1)=0.98

 

ex6.jpg

 

For 2 case     1/(40+1)=0.02

 

ex2.jpg

 


@Rafal.Gaweda  hello. How to set this dialog in English? I was trying many way but it would still display in Russian language. 

I am using RSAP version 2020english display.png

 

Message 18 of 18

Where could I see " SNiP as φ1=1+Ml 1/M1 " in Snip Code ?

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