To design a thin concrete wall

[mnerva]

dear structural
i have to study a wall with 5 cm thickness with heigh concrete strength , it used to support flat plate slab edge wich is supported also by columns 0.12*0.12 m . for calculation without wall shows a deflection 1 cm in the middle of span 4 meters as shown in attached file ,in my case we put the wall between columns , now the wall resist the deflection how could the wall take that deflection and does any buckling happen in wall in this case , how should we design that wall
your idea is very important

 

[SamETABS]

since the shell thickness is considerably low, it needs to get checked for buckling capacity (ref. Flugge or Timoshenko for plate buckling analysis).you have to assume the bottom side as clamped, two lateral side as pinned, and upper side as roller-pinned (to allow for vertical movement).if the shell buckles under lower loads that you expect, the normal way to reinforce it, is to use FRP.

 

[mnerva]

dear sametabs
do you know if etabs or sap2000 or any program can be usefull in this case , thanks

 

[hokie66]

Your vertical elements, both the columns and wall, are much too thin. Where did you come up with these sizes?

 

[haynewp]

Stongly suggest you thicken the walls.

 

[mnerva]

hokie66
in fact the column is a steel kkr 120*120*10 full with concrete , and the wall concrete is c45/55 , , the researcher say it stand according to the labrotary testing , and i say its not according to the deflection of the slab and the buckling occer in the wall and i make some calculation in staad pro with buckling analysis , it shows the displacement in wall is 200 mm , i cant accept thet according to the feeling not calculation do u have any idea , or may be some one had a great look on this subject

your answer is very interesting

 

[sdz]

How is that 50mm thick wall reinforced? It's too thin for conventional reinforcement so is it steel fibre reinforcing?
I agree with the others that it is too thin.

I assume kkr column is a steel hollow section; the concrete fill will have little practical effect.

Is this a research project or something that will actually get built?

 

[mnerva]

its a final applicable project research

i need your idea

 

[hokie66]

This site is not for student projects or homework.

 

[mnerva]

hokie66
It’s not a homework, it’s a real work for multi-storey building, it’s a real economical solution, this research is submitted as an applicable solution.

 

[SamETABS]

I suggest to do some hand calc. for one of the bays (say 4.0x2.4 m2). apply the line load coming from the slab upon the shell. apply the boundary conditions mentioned in my earlier response, and do a proper plate buckling analysis based on referecences I mentioned in my earlier response. usually FEM packages have a lot of bugs when it comes to EXTREME values such as very thin shells or very thick plates. So, try to simlify the analysis as much as you can.

Good Luck

 

[hokie66]

The research you are doing is fruitless, because you are starting with poor assumptions. But if you don't want to take advice that your wall sections are ridiculously thin, you are on your own.

 

[apsix]

Leave a 25mm gap between slab and top of wall and fill it with your favourite gap sealant.
Use WWF and perhaps some fibre mesh for the wall.

 

[kslee1000]

I am more interested in knowing how the vertical edges of the wall are attached to the columns, the bottom edge as well. I think this is a precast thin pannel with high shear and buckling strength, however, it is better to make all sides pinned to alleviate flexural bending. You may achieve pinned condition by providing setting slots with flexable membrane or sealer to allow movement/ensure water tightness/obsorb displacement. Very interested in seeing the final product several years after construction.

 

[JStructsteel]

Is there any lateral load on these walls? Wind, Seismic, etc? 5cm is about 2" correct? You will not build that in USA due to ACI code. Sorry, but the way it is.

 

[oneintheeye]

you wouldn't get any reinforcement in and compact the concrete. This is ridiculous, sorry but, the way it is to quote above.

 

[civilperson]

Thin sections have been successfully used in concrete buildings that include dome, arch or saddle curves, NOT FLAT WALLS.