Do it yourself foundation lift

Hello all, I recently had an issue with my workshop sinking around 80mm at one end. I did engage a consultant to look at a soulution that involve micro strata stabalization of the sub clay and then lifting level using an injected polyurethane foam. The terms of the contract had many loop holes on the warranty and with a price tag of over $20,000AU I looked at way to do this myself. After alot of research I decided to sink piles 2 meters down under the slab and lift the slab from the piles. I did have a Geo-Tech survey done to establish the depth of the piles which was at a minimum of 1.5 meters. The piles where 165mm in diameter but I wanted to increase the bearing area at the base of the piles so designed a hand operated 'Bell Mouth Tool', these are also known as 'Under Reaming Tools'. I based my design on a number of different configuration I found on the net. As I always say "why reinvent the wheel" when the concept is already being used. I did make a number of Video's showing the process from beginning to end and a number of the video's show the tool being used to 'Bell Mouth' out the base of the pile before filling with cement. I did this over 4 episodes starting at - (the first video also shows how I lifted the foundation/slab of my house)
https://www.youtube.com/watch?v=p4a_rJ3QA5Q&t=302s
Its over 12 months ago since I did this work and I survey every month to check for any movement. Initially I had around 4mm - 5mm of drop which I expected as it settled but since the drop it has been as solid as I rock. I did this work with all my machines still in position and can now comfortably go ahead with installing a larger Lathe and Mill.
I've attached a couple of photo's as below to show some of the detail.

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Good job with your under reamer getting the hinge to door ratio just right can be tricky
Back in the 70's right after I returned from the Army I went to work for a foundation drilling company named Watson foundation drilling inc.
we manufactured the drill rigs from truck or crawler mounted to large crane mounted plus all tooling for them such as augers clean out buckets and under-reamers yours looks very similar to the ones we made al beit a lot smaller. We made 1 for the Stan Anderson foundation company in California that was over 12 feet in diameter when closed and opened up to 36 feet

G'Day Frank, thankyou for looking in and commenting. I spent a bit of time on Inventor to get everything working right and had 90% of the parts laser cut from the generated DXF's. Didn't take long to knock up and worked better than I had hoped. Mine was small sized compared to your units, 12 ft diameter and a 36 ft Bell Mouth. Now that's some serious work, would love to see something like that in action, the drive unit must have been huge.
Cam

We only made the 1 unit that large so far as I know but I do remember the doors, drop slide drive and links had to be removed to ship it due to the weight. The barrel shipped on a low bed stretch trailer and the doors went on a flatbed then the drop slide drive section and the links with all of the pins on a 3rd trailer.
We made a lot of core barrels under reamers clean out buckets and augers that were tiny compared to that one many as small as 18" in diameter but the 36 to 72" range was most popular. Mostly I did layout and fit up of the major assemblies like the main frames sliding frames and derricks but occasionally I would make tooling or tack up and weld out the augers or build the water tanks and fuel tanks

Hi Cam,
Nice work and a clever solution.
What was the problem/cause of the slab sinking to start with?

Cheers Phil

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Thanks Me2! We've added your Foundation Lift to our Miscellaneous category,
as well as to your builder page: Me2's Homemade Tools. Your receipt:

<div id="blocks"> <div class="block b1 pngfix"> <div class="bimg"> <div> <a href="http://www.homemadetools.net/homemade-foundation-lift"> <img src="/uploads/221457/homemade-foundation-lift.jpeg"/> </a> </div> </div> <div class="head pngfix"></div> <div class="left pngfix"></div> <div class="right pngfix"></div> <div class="blockover b1 pngfix"> <div class="title"> <a href="http://www.homemadetools.net/homemade-foundation-lift">Foundation Lift</a> <span> by <a href="http://www.homemadetools.net/builder/Me2">Me2</a></span> </div> <div class="tags">tags: <a href='http://www.homemadetools.net/tag/lifting'>lifting</a>, <a href='http://www.homemadetools.net/tag/cement'>cement</a> </div> </div> </div> </div>
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any more videos? always interested in projects like this!
Great job, by the way!
Doug

Thanks for looking in, I'll probably do a description of my workshop overhead crane. Pretty unique design.