Temporary Retaining Wall using Bunker Blocks

[CBrech]

Hello-

We are designing a temporary retaining wall to allow our client to store their product. They are wanting to use, from what they described are "bunker blocks" (image linked below). I am looking to see if anyone has any experience in designing a retaining wall using this kind of material? Any information will greatly be appreciated.

Thank you

Image link:

https://www.google.com/search?q=pre...F-5ZZ34GrLHcM%3A;R4Wx1GldiWYXaM;http%3A%2F%2F

http://www.lymanrichey.com%2Fgerhol...y.com%2Fgerhold%2Fgerholdprecast.aspx;600;450

 

[TLHS]

Unless you use tie backs or a geotextile, it's just a standard gravity wall for overall stability. Then you just have to check to make sure each course is stable against overturning and sliding. Depending on the conditions, you may or may not have to depend on the shear capacity of the key. If you have to, then you'll either have to make your own assumptions about its strength based on the geometry and concrete used or talk to the manufacturer to see if they have testing.

Over more than a small handful of courses, they stop being reasonable as gravity walls because of the quantity required and the necessary space. After that, you need to reinforce the wall somehow. This is typically done using tieback or geotextiles. Neither option is really feasible when your surcharge is a stored product. If you have lots of space, this may not be an issue.

 

[PEinc]

If you are storing product (mulch, gravel, sand, stone, etc.) in front of the blocks, remember that the loader will probably be pushing against the blocks when it scoops a bucketful. You may need embankment behind the blocks to keep them from pushing over.

http://www.PeirceEngineering.com

 

[Signious]

I remember seeing a post similar in the Earth Retention Engineering section a few months back, perhaps a post there could give you some solid results.

http://www.eng-tips.com/threadminder.cfm?pid=255

 

[manstrom]

Aka "mafia" blocks or "Eco" blocks.

They would basically be a gravity retaining wall. I see them used a lot for gravel and mulch storage. [pre][/pre]

When I am working on a problem, I never think about beauty but when I have finished, if the solution is not beautiful, I know it is wrong.

-R. Buckminster Fuller

 

[PEinc]

These blocks are used everywhere. Unfortunately, if you try to design them, the numbers often do not work. Been there, done that.

http://www.PeirceEngineering.com

 

[concretemasonry]

It is difficult for for an engineer to design a wall using a block of concrete that has no real standards or specifications. There are some locally available units that do have testing to provide acceptance and performance, but not commonly available because of freight cost. - In our area, they were called "come-back" concrete because strength was not important and forms were available from several sources since they were not made to sell, but be a cheap way to hopefully get rid of excess fresh concrete.

Was there a standard for the size, shape, strength and features of the "mafia" block?

I never heard of any consensus standard for the blocks the provides for features (joints, shear lugs, etc.).

That is a reason for the gravity wall approach.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[CBrech]

Thank you all for your replies.
We have done some more research, and found out that RetainPro program using the gabion analysis will work with this type of block situation.

 

[precast78]

If the thickness of the block is always the same, it wont hold much. Probably no higher than 2-3 coarse. I would just use static analysis and figure it out your self.

 

[PEinc]

The blocks that I have seen and used are 2' x 2' with available lengths of 2', 4', 6', and 8'. As I said above, designing is hard because, at 2' wide, they usually don't figure for overturning and sliding. To get any wall height, you need to turn the block length perpendicular to the face of the wall and then you need a LOT of blocks and the wall does not look very nice. The contractor usually does not want to buy the great number of blocks that are required once you get above about 6' in height.
I too have used RetainPro's gabion method for these blocks.

http://www.PeirceEngineering.com