How to address post embedded in concrete pier 1

[mfstructural]

I have a situation where I have several circular posts embedded in concrete. The posts support a chain link fence. Therefore, there is wind load on the post transferring moment and shear to the pier. My question is what loads to you see being transferred? I am accounting for bearing of the post against the concrete due to moment, and tension in the pier due to shear at the top of the post. We typically provide .5% steel for confinement. There are no uplift forces so studs have not been included welded to the post.

 

[amec2004]

The followings are the references for design of embedded steel as fix moment connection

PCI Design Handbook Precast and Prestressed Concrete 6th Ed Section 6.9
PCI Engineering Journal Precast Concrete Connections With Embedded Steel Members
ACI Journal Strength of Embedded Steel Sections as Brackets
ASCE Guidelines for Design of Joints between Steel Beams and Reinforced Concrete Columns

The moment capacity depends on the concrete bearing. The additional welded reinforcement will increase the capacity. See attached PDF file.


anchor bolt design per ACI 318-11 crane beam design

http://www.civilbay.com

 

[amec2004]

Sorry I prepare this reply for another thread but post in this one which is incorrect.

Please ignore my reply here or take it out

anchor bolt design per ACI 318-11 crane beam design

http://www.civilbay.com

 

[msquared48]

What you are describing is a pole footing design that involves both lateral bearing on the soil matrix by the concrete footing, and end bearing of the concrete pier footing on the soil.

The metal pole just has to be restrained ith in the concrete, and depending on the size of the metal post and concrete pier, a couple of rebar ties at the top should suffice just fine, if that.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[BAretired]

Steel posts or wood posts? What size? How high? What size of concrete foundation? Give us a sketch.

BA

 

[ztengguy]

If aluminum, you need to address that too.

 

[msquared48]

DO NOT EMBED ALUMINUM IN CONCRETE!!!!!!!!!!!!!!!!!!!!!!! EVER111111111111111

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[TLHS]

Chain link posts are normally steel pipe from my experience, so I'll assume that.

If you're just talking about an independent fence footing, the depth of foundation will govern and you can just extend the post to almost the full depth and loads will transfer happily through bearing.

You'll want to refer to ASTM F567. There's also a fence design guide put out by the Chain Link Fence Manufacturer's Institute that talks about footing selection

http://www.hooverfence.com/chain-link-fence-windload-guide.pdf

.

If you're talking about embedding it in some other structure I'd try to just get away with embedding it in the concrete to develop the moment capacity and then follow the detailing suggestions in the precast literature. I'm familiar with the Canadian manual, but I assume the information's largely the same in the references amec2004 mentioned. It's fairly straightforward.

 

[ztengguy]

Unless you put a protective coating on the aluminum.

 

[msquared48]

Sorry ztengguy, but I'd trust that installation about as much as I trust my mother-in-law.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[Ron]

Mike...been doing coated aluminum embedment in concrete for many, many years. Works fine.

 

[msquared48]

Ron: As others have said, you can't argure with success I guess. What kind of coating are you using?

I am still reticent though, the same as the epoxy coated rebar issue I guess.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[BAretired]

Ron trusts Mike's mother-in-law.

BA

 

[ztengguy]

I cant find it off hand quick, but Sika had one they actually recommended. Your mother in law that nice heh?

 

[ztengguy]

Actually found it in my email after i hit send.

Sikadur 32, Hi-Mod high-modulus, high strength,epoxy bonding / grouting adhesive is the techs recommended.

 

[msquared48]

My mil went in for open heart surgery today. I have mixed feelings
.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[BAretired]

We all wish her well.

BA