Guidelines for anchor bolts in brick and mortar deck

Question

Guidelines for anchor bolts in brick and mortar deck

(OP)

30 Sep 24 15:34

I have a small stainless steel structure that will be anchored into a brick and mortar deck using a flange and bolt application.

This is something I've done before with a solid concrete deck, but my concern with a brick deck is that the bolt may cause the brick to crack and splinter, rendering the connection useless.

I'm wondering if there are any guidelines for designing this kind of anchoring connection. I imagine your two main variables are load and bolt size, thinking a bolt too large compared to the width of the brick will cause it to crack.

For the sake of conversation lets say this is a 4 bolt flange connection into a surface of solid bricks, each brick being 2.25" wide. At the center of the flange the vertical load is 500lbs downward, with a moment load of 16,000 in-lbs.

XR250 (Structural) · Answer 1 · 2024-09-30 17:58:18

Does not seem like a great idea to try to resist moment using this substrate.

EngTipsAccount1234 (Mechanical) · Answer 2 · 2024-09-30 21:08:35

RE: Guidelines for anchor bolts in brick and mortar deck

EngTipsAccount1234 (Mechanical)

(OP)

30 Sep 24 21:08

Why is that?

hardbutmild (Structural) · Answer 3 · 2024-10-01 10:24:41

So bolts are supposed to be anchored to the masonry? Not a good idea in my opinion. You could have a tensile failure of a brick or the whole brick pulled out of the mortar. Why not make a concrete footing below the masonry?

jjl317 (Civil/Environmental) · Answer 4 · 2024-10-01 13:13:00

First - I am not sure I have ever seen a "brick deck", though maybe that is common outside of the US?

Though I guess I would start by looking at the various available anchor products available for anchoring into brick, and the associated limitations for each. In the US, the documentation for most of these anchors is for multi-wythe brick walls only (not decks) and have relatively large spacing requirements, due to the limited localized strength of the brick assembly. The allowable tension capacity of these anchors is relatively small, much less than would be developed with moment you are describing (if 8" anchor spacing T = 16000 in*lbs/8in = 2000 lbs.). Plus, the shear loads would need to be addressed.

If I am envisioning the "brick deck" correctly, I would be surprised if you could get something to calc out.

Hope this helps

dgeesaman (Mechanical) · Answer 5 · 2024-10-01 16:20:27

Just ask the anchor supplier what their rating is for brick and mortar substrate.

I suspect you won't find any anchor suppliers who will agree to that. Then put a proper foundation down.

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Guidelines for anchor bolts in brick and mortar deck