Design & analysis of concrete post (tension element)

[Refaatfaraj]

Dear colleagues,

I am wondering to know. How to design concrete post fixed at edge of cantilevers (the cantilever span about 8.50 m). These posts will be exposed to tension force only as shown in the attached captures. Knowing that the building is an airport lounge (concrete structure)

My inquiries are:

1. Do I use hinges at top & bottom joint of these posts?

2. Shall I run the structural model calculation with non-linear analysis or linear analysis is enough?

3. Does planes sound has any effect on the building, do the planes sound produce any vibrations that can be taken into account. If so, how do I consider that in my structural model?

4. May I know if there are any other cautions for these post members should be considered in my structural analysis?

Any help will be highly appreciated

Thanks in advance
Refaat

http://files.engineering.com/getfil...54a0-4a1e-ae2e-0108f2141bfa&file=Captures.zip

 

[BAretired]

1. Do I use hinges at top & bottom joint of these posts?

They are not posts. They are hangers. Hinged connections are okay but not necessary. If the hangers are cast in place, you could have dowels at the bottom and extend the reinforcement at the top. With full continuity, you will generate small moments but they should not play a significant role in the design.

Another possibility is to use a single steel hanger adequately anchored at each end to ensure transfer of tension force to the beam above and below. In that case, the concrete around the steel member would serve only as fire protection for the hanger.

2. Shall I run the structural model calculation with non-linear analysis or linear analysis is enough?

Why would you use non-linear analysis?

3. Does planes sound has any effect on the building, do the planes sound produce any vibrations that can be taken into account. If so, how do I consider that in my structural model?

Vibrations from planes would have little effect on your structure and may be ignored.

4. May I know if there are any other cautions for these post members should be considered in my structural analysis?

Make sure both levels are adequately supported by formwork until the upper beam has fully cured and is able to carry the full load by itself.

BA

 

[dik]

That cantilever on the bottom left looks a little dodgy... Looking at the picture, it's a significant structure and you might want to have someone local look at it in detail.

Dik

 

[WARose]

1. Do I use hinges at top & bottom joint of these posts?

Depends on how they are connected. If they can transfer moment.....no releases.

2. Shall I run the structural model calculation with non-linear analysis or linear analysis is enough?

Seems like a linear analysis to me. (Unless you are doing something unusual seismically.)

3. Does planes sound has any effect on the building, do the planes sound produce any vibrations that can be taken into account. If so, how do I consider that in my structural model?

For the overall structure.....the vibration from the planes will probably be meaningless. For non-structural components and noise control.....you may want to check/ask around: be sure what criteria will be acceptable to them. (This isn't industrial where you can get away with a lot.)

4. May I know if there are any other cautions for these post members should be considered in my structural analysis?

You call them tension members.....but I would run it as a member that could develop both compression and tension. (Or maybe everything based on the connection.)

 

[Refaatfaraj]

Hello BAretired & WARose

Many thanks for your guidance, I am really grateful.

1.Hangers is really the specific description for my (tension member). Thank you a lot.
2.Actually, I am going to use steel reinforcement as illustrated in the attached capture. Some reinforcement bars will be fixed in the core of the hanger because I am afraid from corrosion of external bars induced by carbonation .moreover I will ask the project contractor to coat the hanger reinforcement with appropriate chemical material.
3.There are two approaches in Adsk ROBOT software to define a structure member as a tension element.
The first approach to define moment releases at the top and bottom hanger joints then the structural analysis will be automatically based on static linear analysis. The second approach to define the hanger as truss member which is carried only tension force. In this case the software will run the structural analysis based on non-linear analysis (please, take a look to the attach capture).
4. By the way I have two concrete shafts in this project as illustrated in the attached capture. These concrete shifts without any openings. Is there the any effect from planes vibration on these shafts since the air inside is restricted .

Note : all the dimensions illustrated in the capture in (meter) whereas in Autocad file in millimeter

http://files.engineering.com/getfil...7-b007-2cd370e84854&file=Airport_a_lounge.zip

Kind Regards
Refaat

 

[Refaatfaraj]

Hello dik ,

Thank you for the support given.

You are right. I have attached here the project plans (AutoCAD). I hope it will give good idea to help me.

Note : all the dimensions illustrated in the capture in (meter) where as in Autocad file in millimeter

http://files.engineering.com/getfil...7-b007-2cd370e84854&file=Airport_a_lounge.zip

Kind Regards

Refaat