Deep Soil Mixing

[Paradox]

Big day today at one of the public works projects I’m involved in.

Assembling a 180,000 pound auguring machine. Tomorrow the team commences work on 440 six foot diameter in ground mixed soil columns averaging 20 feet in depth.

The process is called deep soil mixing. They mix the soil with concrete within the augured hole. It essentially strengthens up the pad and negates the need for caissons and the like.

First time I’ve seen this done in my 40 plus years of construction. It is definitely interesting.

 

[4Waters]

Big day today at one of the public works projects I’m involved in.

Assembling a 180,000 pound auguring machine. Tomorrow the team commences work on 440 six foot diameter in ground mixed soil columns averaging 20 feet in depth.

The process is called deep soil mixing. They mix the soil with concrete within the augured hole. It essentially strengthens up the pad and negates the need for caissons and the like.

First time I’ve seen this done in my 40 plus years of construction. It is definitely interesting.


View attachment 1006557 View attachment 1006558 View attachment 1006559

Where is this at?

 

[Paradox]

Where is this at?

Slymar, CA

 

[4Waters]

Slymar, CA

Interesting, earthquake country, I'll be at Balboa and Foothill next week.

 

[Taboma]

Never seen or been on a project where that was done, so this ???

 

[Waterjunky]

That's an interesting one. I have seen 100+' deep slurry walls built in place with the longest reach excavator I've ever seen.... Sounds like a somewhat similar idea. Never looked like much when they were doing it as the mix was filling the 3' wide trench the entire time until they started lifting the bucket out of the muck and it just kept coming out, and out and out. Built like a standard excavator, just stupid long arms. One normal size scoop at a time, over 100' deep and several miles long when they were done.

 

[Paradox]

Never seen or been on a project where that was done, so this ???

View attachment 1006567

That looks like it. The mixture flows through the hollow stem of the auger.

We have an IOR older than me and he’s never seen It. Likewise, we have a super with roughly 30 years experience and he has never seen it either.

Perhaps it is more prevalent outside of So Cal.

 

[4Waters]

That looks like it. The mixture flows through the hollow stem of the auger.

We have an IOR older than me and he’s never seen It. Likewise, we have a super with roughly 30 years experience and he has never seen it either.

Perhaps it is more prevalent outside of So Cal.

So what is this supposed to support?

 

[Paradox]

So what is this supposed to support?

The foundation (spread footings, grade beams, etc.) for a 3 story 60,000 sq. ft. Building.

 

[Taboma]

The foundation (spread footings, grade beams, etc.) for a 3 story 60,000 sq. ft. Building.

Is the plan then to keep these X-number of feet below grade, then form the footings and grade beams so they rest on top of them ?

 

[Paradox]

Is the plan then to keep these X-number of feet below grade, then form the footings and grade beams so they rest on top of them ?

Yep. Rough grade #1 for the mixed soil columns and, once completed, rough grade #2 for the foundation work. The elevational difference is 4’2” which leaves 10 inches for the SOG including the sand and barrier. Finish floor is 5’ above the top of the mixed columns. The slab is going to be colored and polished. No floor covering anywhere (except the bathroom ceramic floors) in the building. It will be heavily used and this makes sense from a life cycle cost stand point.

 

[TITTIES AND BEER]

I did a 1,200,000 ft.² pad all lime stabilized 9 foot lifts cut with a saw 1’ at a time also did some concrete

 

[Javajoe]

I built a 3 story in Riverside where we dug down 30’ then bored 4’ holes 50’ deep on 10’ grid pattern and pressure grouted them up. What a messy process it was

 

[Taboma]

I built a 3 story in Riverside where we dug down 30’ then bored 4’ holes 50’ deep on 10’ grid pattern and pressure grouted them up. What a messy process it was

Holy crap, whatcha building on, old landfills ?? Or ancient swamps ?

 

[Javajoe]

Holy crap, whatcha building on, old landfills ?? Or ancient swamps ?

Lol, old river bottom downtown. Subterranean parking garage and 2 story medical on top

 

[shock22]

Big day today at one of the public works projects I’m involved in.

Assembling a 180,000 pound auguring machine. Tomorrow the team commences work on 440 six foot diameter in ground mixed soil columns averaging 20 feet in depth.

The process is called deep soil mixing. They mix the soil with concrete within the augured hole. It essentially strengthens up the pad and negates the need for caissons and the like.

First time I’ve seen this done in my 40 plus years of construction. It is definitely interesting.


View attachment 1006557 View attachment 1006558 View attachment 1006559

I was General Superintdent with them for 17 years that will make an nice mess

 

[HNL2LHC]

Cool to see new technologies in construction. Makes me even more impressed with how things were built before the advancements, hover dam and the likes.

 

[Racer56]

That looks like it. The mixture flows through the hollow stem of the auger.

We have an IOR older than me and he’s never seen It. Likewise, we have a super with roughly 30 years experience and he has never seen it either.

Perhaps it is more prevalent outside of So Cal.

It's very common in northern California around the bay area. I bet they are doing it to mitigate liquefaction due to the sandy soils in the area. I do deep foundations for a living and the soil improvement contractor's are our enemy. Cast in place concrete piles (caissons) for the FTMFW!

 

[DLC]

My buddy built a 5 story hotel on the beach 30 feet below sea level was the deepest part of the parking structure.

he had to pump out water 24/7 drill rock filled piers under the entire structure to stabilize total depth was 60ft below the 30 ft parking and then pour a continuous monolithic structure to keep the water out

it was crazy

 

[WhatExit?]

Interesting technology. Where in Sylmar is that at?

 

[Paradox]

Interesting technology. Where in Sylmar is that at?

A block or so off of Hubbard.

 

[shock22]

It's very common in northern California around the bay area. I bet they are doing it to mitigate liquefaction due to the sandy soils in the area. I do deep foundations for a living and the soil improvement contractor's are our enemy. Cast in place concrete piles (caissons) for the FTMFW!

Also deep foundation person start with Anderson drilling hating soil improvement companies then we got bought by Keller and became Hayward Baker

 

[Paradox]

Also deep foundation person start with Anderson drilling hating soil improvement companies then we got bought by Keller and became Hayward Baker

I didn’t know the history but know of Hayward Baker.

The DSM process is new to me and I posted because I found it interesting. Perhaps I don’t get around as much as I thought. Pretty much every project I’ve be on (that required augmentation) utilized CIP caissons, driven piles or deep overex with geo-mat.

 

[Nordie]

I might be biased, but I prefer caissons. Interesting concept though, almost seems value engineered to me.

 

[HBCraig]

@rickdarling

What rig was used? Was it mixed via paddles?
Any Bentonite used?

And yes, I know exactly what you are talking about.

 

[HBCraig]

I didn’t know the history but know of Hayward Baker.

The DSM process is new to me and I posted because I found it interesting. Perhaps I don’t get around as much as I thought. Pretty much every project I’ve be on (that required augmentation) utilized CIP caissons, driven piles or deep overex with geo-mat.

Hayward Baker was bought by Keller Group a few years ago. I see a lot of CFA pile. Continuous flight auger

 

[racektm]

@rickdarling

What rig was used? Was it mixed via paddles?
Any Bentonite used?

And yes, I know exactly what you are talking about.

Looks like a Bauer,

 

[Nordie]

Best part of my job is when the drillers leave

 

[Paradox]

Looks like a Bauer,

@rickdarling

What rig was used? Was it mixed via paddles?
Any Bentonite used?

And yes, I know exactly what you are talking about.

No Bentonite. Here’s a pic of the rig and auger head.

 

[HBCraig]

Looks like a Bauer,

It is a Bauer. Oh well, we all make mistakes.

 

[HBCraig]

Best part of my job is when the drillers leave

Or the Pile Bucks. Feel bad, those dudes get dirty. Damn dirty

 

[racektm]

It is a Bauer. Oh well, we all make mistakes.

You work with Liebherr?? I have never seen a Liebherr drill rig, I know they make them, I have just never seen one on a job. Now days I typically see Soilmec or Bauer. Back in the "old" days, everything was crane mounted.

 

[Paradox]

Smaller caisson augering for a retaining wall at another project. In general, seems to me that things have gotten a lot more efficient than back in the day..

 

[racektm]

Smaller caisson augering for a retaining wall at another project. In general, seems to me that things have gotten a lot more efficient than back in the day..


Thats an excavator mounted Lodril, still old school technology, but very efficient in the right application. They all have there purpose and application, just hard to beat a Bauer/Soilmec type rig for production drilling,

 

[HBCraig]

You work with Liebherr?? I have never seen a Liebherr drill rig, I know they make them, I have just never seen one on a job. Now days I typically see Soilmec or Bauer. Back in the "old" days, everything was crane mounted.

Yeh, I used to sell those drill rigs. They are solid machines. I run the west coast for Liebherr but for all the mobile cranes