×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Anchor Sizing
2

Anchor Sizing

Anchor Sizing

(OP)
What are most using these days to size Anchor Rods?
There are several approaches including ACI 318 App D & AISC.
I was just curious what folks are using.  

RE: Anchor Sizing

We grimace, gag, and guffaw our way through App. D of ACI 318.

 

RE: Anchor Sizing

(OP)
JAE-
I feel your pain there.
I do not fully understand the Ductile vs. Brittle requirements of D.4.4.
 

RE: Anchor Sizing

A ductile steel element is defined in D.1 as an element with a tensile test elongation of at least 14% and reduction in area of at least 30%.  I think most steels that we would use for anchor rods meet this criteria.

As for designing anchor rods, I use Appendix D.  I suppose I'll post my spreadsheet and get some input.  Take a look at this and let me know what you think.

It's not letting me upload the spreadsheet, I think it's too big.  Does anyone know an alternate way to post it?

RE: Anchor Sizing

Develop a simpler method for designing anchors so that you can make a spreadsheet that can fit winky smile

RE: Anchor Sizing

As you can tell, I am also afflicted with Appendicitis D

RE: Anchor Sizing

Try uploading it to one of the free file sharing sites such as megaupload,box.net,rapidshare etc. and post the link for download.
Don't know if that is against forum rules. Maybe one of these days I should read it entirely. :)

RE: Anchor Sizing

(OP)
I'm still a little conflicted on the ductile requirement. It seems like it goes further than a material requirement alone and involves properly tying the rods within the pier, etc.
 
Appendix has been a thorn in my side for a long time now too.
You mix that together with a garbage Design Guide One from AISC and you have a flat out abomination, in my opinion.

Do those of you using ASD in your structural steel design, factor your reactions accordingly in order to use App. D or do you simply size your anchor rods using ASD?   

RE: Anchor Sizing

Just go right to the Hilti catelog.

RE: Anchor Sizing

StructuralEIT:
Have you tried to attach compressed (zipped) file?
IV

RE: Anchor Sizing

Still not working with the zipped file.  I'm out of town the next couple days, but will work on a way to upload it when I get back.  Does anyone know of a site to post at like slickdeals talks about?

Teguci,
Hilti doesn't give values that comply with App. D.  They only give values for non code compliant anchors using ASD.

RE: Anchor Sizing

Try the method in the PCI Design Handbook.  

RE: Anchor Sizing

Bones-
I recognize that Hilti has post-installed, code compliant anchors, but they don't give you values for them like they do for the non-code compliant anchors such as HIT HY-150.  You still need to go through the App. D equations as well as the equations on AC 300 (I think that's the reference).  It's not as simple as going to the Hilti catalog.  

RE: Anchor Sizing

(OP)
where is it located in the PCI Ron?
I have the 5th edition.

THanks.  

RE: Anchor Sizing

Need the 6th Edition. Easy to understand what they are doing.

RE: Anchor Sizing

(OP)
I have that one here some where too...point me to a page?
 

RE: Anchor Sizing

SEIT -

I see what you mean now - You can't just pick Hilti anchors with generic capacities, you have to do a unique Appendix D calc for every situation. I thought you meant Hilti anchors can't be designed through Appendix D.

There is also a European equivalent to Appendix D: CEN/TS 1992-4-1:2009. It's similar to Appendix D in it's complexity but also seems more comprehensive and descriptive. More examples. I think it's written by the same gang of anchor gurus that wrote Appendix D.  

RE: Anchor Sizing

Section 3 of AC308 has some ammendments for the ACI318-08 Ap. D. If to use chemical anchors, use ACI318-08 Ap, D, the ICC-ESR of the anchor and AC308 as reference.  

RE: Anchor Sizing

Does anyone use the Simpson Anchor software?  It is set up to use headed anchor bolts and hooked anchor bolts as well as their own post-installed anchors.  It is a free download.

RE: Anchor Sizing

Download HILTI Profis software.  It's free, extremely easy to use, and current with all Appendix D requirements.

RE: Anchor Sizing

Had to design a heavy connection to existing concrete columns with epoxy anchors this weekend. What a pain. Hilti has the values for the ACI calculations but I couldn't use the PCI method because it doesn't cover epoxy. Since ACI 05 doesn't require their method for epoxy I used the old method (which has worked for years and years)to design the connection.

It has seemed to me for a while that the folks that write the codes are out of touch with the real world where calculations need to be done in real time. Am I starting to sound like an old fart yet? But, at least to me, after you go to construction sites and see how the work is really performed this level of complexity in calculations isn't justified.

RE: Anchor Sizing

(OP)
Ron-
I am not even very old and I agree with you.
There are a lot of academic types in the code world. You know, the types the go to school when they are 18 and stay there for life, never having touched a wrench or a calc pad.
I think a lot of this stuff comes from these gusy thinking the codes are neat science projects pc3

RE: Anchor Sizing

I think Appendix D is a joke. I really believe that PCI should take it by the horns and rewrite it or make it more engineer friendly.

RE: Anchor Sizing

(OP)
It is TERRIBLE IMHO.
I was doing some more side blow out and tension pullout calc's yesterday....i have done these many times but I can never get over what a convoluted mess APP D is mad

RE: Anchor Sizing

slickdeals like I said above PCI 6th edition has a procedure that is much easier to follow it just doesn't address post installed anchors. I tried to use the Hilti program and it seemed that you were limited in what you could do. Maybe didn't spend enough time to understand what it was saying. Plan to go back and review when time allows.

RE: Anchor Sizing

Ron, I agree. But is the PCI method code accepted? As in would it fly by a plan reviewer?

RE: Anchor Sizing

The PCI manual says that ACI allows alternate methods and that their method meets the ACI criteria.

RE: Anchor Sizing

ACI 318-08 Section D4.2 covers the acceptance of other design models.  Does PCI method meet the requirements of this section?  Honestly, Appex. D is not that hard to do, the calculations take only a few minutes more than the UBC equations.  Appex. D comes out of an extensive testing program to test the performance of anchor bolts in plain concrete, so the equations are based on tested data.  Do not know anything more "wrench" then actual test data.  My issue with Appex. D is when you add the effects of reinforcement, I feel they grossly underestimate the additional strength provided by the reinforcement and place unreasonable limits on the reinforcement that can be used to transfer the load into the concrete.

RE: Anchor Sizing

I use through-bolts to avoid Appendix D altogether.  If through-bolts are not appropriate, I chain the anchor to an equivalent "deadman" in the concrete to avoid Appendix D.

RE: Anchor Sizing

(OP)
Through bolts :) ?

RE: Anchor Sizing

I have used through bolts myself when I have hanging load from a slab. In that case all I check is for punching shear around the base plate at the top of the slab. Not always the best choice because Mr. Architect will have issues with it.

You can use through-bolts to attach bollards to slabs as well, probably the only way you can get a bollard to work on 6 or 8 inch slabs.

RE: Anchor Sizing

The Hilti catalogue is based on Eurocode.

RE: Anchor Sizing

slickdeals:

Not sure how code compliant it is, but PNA has a cast in product for bollard bases.  More info at:

http://www.pna-inc.com/products/bollard_base/

Back to Appendix D: Powers Fasteners also has a program for designing to Appendix D with the option to use cast in bolts.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources