Likely very simple Beam calcs...

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The discussion centers on concerns regarding the structural integrity of cantilevered shelving supported by a wall, specifically a 100mm thick breeze block partition. The user is considering loading the shelves with up to 100kg each and is worried about the horizontal load at the wall connection, which they estimate to be 315N. Responses emphasize the importance of accounting for additional loads, such as people using the shelves, and clarify that the pivot point for potential toppling is at the floor connection of the columns. Overall, while the user's calculations seem reasonable, there is a suggestion to ensure the wall's stability and structural ties are adequate to support the intended loads.
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Cantilevered shelving supported by a wall
Afternoon Guys

Wonderful forum & recommended by my daughter who uses it regularly to help with her homework, so thank you all for that.

Its been many years since I have done any calculations regarding beams and columns, but upon looking at buying a detached garage locally, we noticed it would come with some shelving. I know the material well as I use it where I work so I've got no concerns about the cantilever arms, the material, compressive loads or shear loads (Each arm is rated to 2500N point load at the tip)

However what does worry me is the reaction where the uprights are held by the wall and subsequently whether it could do damage to the 100mm thick breeze block partition wall

Below is the diagram for the shelving uprights. There are 3 uprights in total with shelving boards linking the three. The most I would plan to put up there is 100kg per shelf and assuming a pointload at the tip worst case. (Hence 327N per arm)

My only real concern is the horizontal load being applied to the wall at R1 as it resists toppling. My calculations look to simple imo and with my uni days long behind me, Im not at all confident in them. That said, if they are even close to being right then 315N total horizontal load on the wall doesnt worry me at all.

1750763661112.webp


Any insight would be greatly appreciated. Cheers guys :)
 
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First a warning: I have never done this kind of analysis before putting up shelves. I just tug on things to see if they break.
That said, I have two comments:
1) If you are going to put as much as 100Kg per shelf, I would add at least another 40Kg for people using the shelves to steady themselves as they load or unload those shelves. The worse time for these shelves to collapse would be when someone is right under them.
2) I believe the model you are describing has the column pivoting at its connection to the floor. So any rotational force will be about the axis that follows along the column bases. In other words, the "toppling" you are concerned about would have the shelves and the columns rotating away from the wall as a relatively rigid unit - with the axis of rotation being that line on the floor.

Except for that 40Kg (or whatever) margin, I believe you're figures are correct.
 
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Thanks for your response :)

Not sure if im just overthinking things.

e.g. If I had bought a boxing bag arm with a 1m lever & a 100kg bag, I would not think twice whether a block wall would be able to take it. Forces wise, that is probably worse than this shelving given it would be creating a 981Nm moment on a more concentrated area with less fasteners.
 
I thought of it this way:
Instead of 2 shelves on the right, I put one shelf on either side of R1, each 45cm. Then, for the one on the right, I ran lines down to support those 2 PL loads directly below it - so that those original shelves are no longer needed and can be removed. Then I added 2PL to the end of the R1 shelf that extends to the left - so they balanced.
When I did that, it becomes clear that the elevation of the shelves above the floor doesn't matter. And it looked as simple as it is.
 
GYnx85 said:
TL;DR Summary: Cantilevered shelving supported by a wall

Afternoon Guys

Wonderful forum & recommended by my daughter who uses it regularly to help with her homework, so thank you all for that.

Its been many years since I have done any calculations regarding beams and columns, but upon looking at buying a detached garage locally, we noticed it would come with some shelving. I know the material well as I use it where I work so I've got no concerns about the cantilever arms, the material, compressive loads or shear loads (Each arm is rated to 2500N point load at the tip)

However what does worry me is the reaction where the uprights are held by the wall and subsequently whether it could do damage to the 100mm thick breeze block partition wall

Below is the diagram for the shelving uprights. There are 3 uprights in total with shelving boards linking the three. The most I would plan to put up there is 100kg per shelf and assuming a pointload at the tip worst case. (Hence 327N per arm)

My only real concern is the horizontal load being applied to the wall at R1 as it resists toppling. My calculations look to simple imo and with my uni days long behind me, Im not at all confident in them. That said, if they are even close to being right then 315N total horizontal load on the wall doesnt worry me at all.

View attachment 362503

Any insight would be greatly appreciated. Cheers guys :)
When you say breeze block you mean the kind with the holes through it that look aesthetic like this?
1750805020118.webp


Is the wall actually freestanding, like this:

1750805201965.webp


such that it isn't structurally tied at its top to anything?
 
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