Load carrying capacity of angle leg in eccentric load on one leg

[N G P]

Hello Guys,

How do we can find the capacity of an angle section in carrying a uniform load on one of the leg while the other leg is bolted to a concrete wall at alternative spacing(say 500mm). I have attached a hand sketch for clarity.

Thanks for your help in advance

 

[mmarlow]

You need to check:
Toe bending (just get a section of the toe and check it in flexure). you might need to check a couple locations depending on section properties
Anchor pull out (get the reaction at the anchors location by using a FBD)
Angle bending (shouldn't be an issue with 500mm spacing)
Maybe anchor bearing

Also, I would refer to it as anchored, not bolted. It looks like you have chemical anchor shown?

These calcs are pretty straight forward, but if you need a reference. Masonry structures Behavior and Design by Ahmad Hamid has some good examples on shelf angle checks and considerations.



-MMARLOW EIT

 

[Celt83]

I'll add to be careful of your deflection checks with these things it's not just simple beam deflections you need to account for horizontal leg, vertical leg, angle rotation, and anchor elongation.

I'm personally not a fan of the angle orientation you have shown, I like to have the heel pushing against the backup material so I have something stout to form the compressive force of the couple between the anchor and the angle bearing against the back-up.

Open Source Structural Applications:

https://github.com/buddyd16/Structural-Engineering

 

[mmarlow]

Celt83,

I agree, flipping it will help guaranteed that the flexural and deflection concerns will be in the toe. Also the reference I left in my previous post gets into shimming the heel of the angle out.

-MMARLOW EIT

 

[KootK]

I've been using modified versions of the method shown in the PCI manual, treating the continuous angle as discrete clips near each bolt. If the stuff being supported has any internal stiffness, I feel that this is a better reflection of behavior anyhow.

I agree with flipping the angle where possible but acknowledge that there are situations where that is not desirable for various reasons.

if you need a reference. Masonry structures Behavior and Design by Ahmad Hamid has some good examples

I'll check that out. You must be practicing in Canada or, at least, have been educated there.

 

[mmarlow]

Kootk,

Born and raised in Northern NY. Educated and practicing in Massachusetts. Just curious, what makes you think I was educated in Canada?



-MMARLOW EIT

 

[KootK]

Just curious, what makes you think I was educated in Canada?

Playing the odds... unsuccessfully it would seem. When you go to engineering school in Canada, they usually make you buy engineering books authored there. Because it's such a small market, there's usually only one, or at most two, decent books to choose from for any one material design course. And the Drysdale book is it for masonry (University of Manitoba or something). Consequently:

1) I see the Drysdale book in the collections of many Canadian engineers.

2) I rarely see the Drysdale book in the collections of non-Canadian engineers.

Heck, a former protege actually wrote a few sections. It truly is an excellent masonry text. Up there in the top three for sure for north american offerings in my opinion.

 

[jayrod12]

Koot,

I believe the text you might be referring to when you reference UofM is Masonry design for Engineers and Architects by Hatzinikolas and Korany. In that book they reference major contributions from John Glanville who was the Masonry guy for a long time and was a professor at UofM for 35 years. I don't think I've ever seen the one referenced by mmarlow

 

[KootK]

I might be wrong about the university but I'm definitely not wrong about the book. This, literally from the desk of KootK...

 

[jayrod12]

Oh I've got that one too. Didn't even realize the authors. I believe you're correct on that book as well. I believe Drysdale is also a UofM guy.

If you want a more practical book, take a look at Hatzinikolas' book. It's much like the Kulak and Grondin book for steel, but the masonry version. Great for people just learning.

 

[KootK]

If you want a more practical book, take a look at Hatzinikolas' book.

Already got it. I agree, it is a good, practical book.

 

[mmarlow]

KootK, nope, not from Canada. However, I do find this book to be very helpful. Unfortunately throughout undergraduate and graduate work I never took a masonry course, and I was told that this book (a long with the masonry design guide) would be of great use.

-MMARLOW EIT

 

[StrucDesignPE]

The OP may find this article helpful for checking the bending in the angle leg. The second page has an easy procedure to follow.

https://www.structuremag.org/?p=3304

 

[bob33]

Drysdale is at McMaster and is also chair of CSA S304 - Design of Masonry Structures. Hamid is at Drexel. Glanville also was involved in the design of Place Louis Riel in Winnipeg, one of the earliest and largest engineered masonry buildings in North America.

 

[slickdeals]

1. In your original detail, depending on the magnitude of your load and the moment arm between the tip of the angle and the bolt, make sure that you make the angle leg thick enough to avoid prying action. It shouldn't be a controlling factor, but depending the loads you are resisting, it can.

2. Also remember to do a tension/shear interaction on the anchor.

3. Would recommend providing a horizontal slotted hole to allow for field tolerances. It always happens to me that where I want to put a post-installed anchor, there is always a piece of rebar. If you have a horizontal rebar, you're SOL unless you allow them to drill through.