Retaining Wall Replacement Advice

[JF94]

I am working on a project where there is an existing retaining wall that is failing. My job is to come up with a new wall design to encompass the perimeter of the building by either using a hybrid masonry stem with concrete footer design and/or a MSE wall using geogrid reinforcement or some other anchored reinforcement. I have no experience designing MSE walls let alone a project where the existing wall needs to be removed and replaced. I've attached images and PDFs for reference.

I want to specify a maximum height above grade of 4'-5'. The existing retaining walls are 4' maximum with one section of wall that reaches 6' (North elevation view). The section of wall that reaches 6' in height would require a concrete footer that is too large therefore I need a different solution.

The issues are:

[li]The existing walls back up close to the existing building foundation
[/li]
[li]I am trying to reduce the footprint of this wall as much as possible as there are underground utilities in the vicinity[/li]


Amy advice is greatly appreciated!!

 

[EireChch]

My first comment is that its a footing not a "footer". !!! Sorry, it bugs me a lot for some reason!

What ground is the retaining wall supporting? SAND, CLAY etc. Are there any groundwater issues?

But to answer your question, I think a concrete filled block L wall with a key would be a good idea, cant get much smaller than that in terms of foot print without going with a piled wall solution which is probably to expensive for what you are doing.

You seem to have already shown your zone of influence line from the existing foundation.

For the majority of your sections you look ok, except for the very top right and maybe bottom left sections. This is getting close, you could look to underpin the existing foundation, which would be expensive.

You could look to install timber pile wall to provide temporary support to the foundations. This would be a 450mm dia hole, 250mm dia timber pile, concrete encased. One every 1.2m or so, subject to a design.

There are also some segmental block retaining walls, which may include a geogrid like an MSE.

 

[dik]

Can you use segmental pre-cast retaining structure? Attractive and functional...

Rather than think climate change and the corona virus as science, think of it as the wrath of God. Feel any better?

-Dik