Tools for Baseplate and Anchor Design?

[connectegr]

What software or design references do you use for design of baseplates (or embeds) and anchors?

We frequently deal with non-concentrically loaded baseplates. With combinations of shear, moment, and axial forces. Whether due to the cross sectional shape of the column or the position of the column relative to the plate center, forces are concentrated unevenly. This results in uneven loading of the plate and anchors. These calculations can be time consuming by hand, and are often trial and error in order to determine a pattern, anchor size, and plate thickness.

We have similar issues with embed plates.

http://www.FerrellEngineering.com

 

[slickdeals]

HILTI PROFIS seems to work fine for such applications. They have hex, heavy hex, square and heavy square for anchor bolts and also AWS headed studs in embedded plates.

 

[connectegr]

We thought so...
According to Hilti, PROFIS considers the plate as rigid and thus no tension amplification due to prying. This will be more clearly stated in version 2.1. See attached response from Hilti.

http://www.FerrellEngineering.com

 

[abusementpark]

I've used the Simpson program, but I hate it because it always tells me what I am trying to do is in gross violation of the code for the new "cracked concrete" provisions. Also, it doesn't design base plates, only the anchorage. I haven't found anything that does both base plate design per Design Guide 1 and anchorage design per ACI Appendix D.

 

[RFreund]

CSC's Tedds just came out with a calc for Base Plate combined with Anchor bolts. I'm not sure how robust/flexible it is or what sort of configurations are available as I have yet to use it.

EIT

 

[MiketheEngineer]

have you tried Engineering International ans/or Archoneng.

Both cheap and may solve your problems

 

[southard2]

I use Ram Baseplate for my baseplate designs and really like it a lot. Its a bit out of date code wise and I'm not sure if they've updated the program lately but it does handel both tension loading and moment loading on the baseplates. It will also give you the loads on the anchor bolts. Then I basically use ACI appendix D for the anchor bolt designs. For the moment case you'll typically have two bolts in tension. For the uplift case all four bolts will be in tension. So depending on the load case a decent spreadsheet can help you navigate ACI appendix D.

I used a trial run of Dimensional Solutions anchor bolt programe and it seemed pretty robust regarding ACI appendix D solutions.

John Southard, M.S., P.E.

http://www.pdhlibrary.com

 

[Lion06]

I'm with Southard - I design the plate with RAM Baseplate (admittedly, I hate that it won't do biaxial bending), then pull out of the anchor forces and dump that into my ACI App. D spreadsheet to design the anchors.

 

[WillisV]

Ram Baseplate is now part of the Ram Connection and can design for biaxial bending as well as perform Appendix D type calcs for most general conditions.

 

[RFreund]

Attached is an example of Tedds print out for large moment design. Calcs are very "see through" with this program. Don't know how it compares with Ram.

EIT

 

[dozer]

RFreund,
The TEDDS report seems nicely laid out. I compared it to RAM Connection and noticed a mistake. Under pullout strength, TEDDS shows Abrg=1.5 in^2 for a 3/4" bolt but RAM gives 0.654 in^2. I believe RAM is correct. If you agree, I recommend you report this as a bug.

Another difference I noticed is that RAM will only let you consider friction if you use a shear lug. That doesn't make a lot of sense to me. I'll try to post the RAM output when I get a little more time.

 

[connectegr]

Has anyone tried RISA Base? We primarily use RISA for our structural analysis.

http://www.FerrellEngineering.com

 

[racookpe1978]

Bookmarked for reference.

 

[dozer]

Here's a sample of RAM Connection's output. I used the same data as the TEDDS example above. There is also an option to have it show all of the equations. Nice for seeing how it arrived at the answer but pretty busy, not very pleasing to the eye.

One thing I like about RAM is that it gives the utilization ratio for each mode of failure so you can easily see what controls.

 

[RFreund]

Dozer - Nice catch. I believe that is a manual input for Abrg. However I think that was CSC's standard example. I do like the utilization ratio. In Tedds they will show you the ratio in the design module but it is not shown in the output although there are a couple of output options. I have not compared the results but sounds like the two are pretty similar.

EIT

 

[bluetree]

Dont have a software suggestion for you, but a good design reference is the AISC Design Guide No. 1.

 

[jpstruct]

I agree with bluetree, that is what I use. If you follow the guidelines laid out DG #1 it is actually pretty easy to come up with a spreadsheet to do these calcs for you. Just don't follow the spreadsheet blindly.

As far as the embedment goes, this has been a thron in the side of a lot of engineers in my office. A lot of guys use the old school method of 17d, where d is the diameter of the bolt or rod but I'm not one to just blindly follow something because "that's the way its always been done". I reccommend ACI 349.2R-07.

 

[Lion06]

Jp-

it's only easy to make a spreadsheet for basic cases. I made a spreadsheet a while back and it's exceptionally involved. This is especially true where the breakout cone is controlled by three sides for tension or where the shear force is parallel to the edge instead of perpendicular. Also, if there are eccentricities for shear or tension makin sure that the correct anchors see the additional forces from an elastic bolt group analysis only for the appropriate conditions is no smal feat either.

 

[slickdeals]

SEIT:
Are you accessing the forums during the lunch break while taking the PE?

 

[Lion06]

I'm allowed to be here at lunch, aren't I? I'm bored out of my mind sitting in my car. It took all of 7 minutes to eat my lunch. I haven't seen any of the afternoon questions, so I didn't think it would be a problem. Am I mistaken?