×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Vibro Stone Columns

Vibro Stone Columns

Vibro Stone Columns

(OP)
Does anyone have some good design references/procedures for vibro stone columns? It would be nice if calculations were included.

Thanks for the help,

RE: Vibro Stone Columns

See if you can find anything by the VibroFlotation company.

RE: Vibro Stone Columns

I've attached an article on the engineering principles of Control Modulus Columns (CMC), which are a modern day alternative to the old vibro-stone columns. Many of the principles still apply.

I don't know what soils you're up against, but in my area the old stone columns have been entirely superseded- very few contractors are able to install them to satisfaction...if the soil conditions aren't clearly defined there is a risk of poor performance and serious cost overruns, particularly with very soft clays where the vibro stone extrudes into the surrounding clays.

I'd recommend that you run your proposal past an experienced contractor at an early stage of design- there may be serious limitations that you're not aware of.

All the best,
Mike

RE: Vibro Stone Columns

Mad Mike - vibro stone columns are perfect for soft clay. Extruding into the surrounding soil is the point. You improve soft clay by increasing the horizontal stress thus increasing Ko.

Vibro stone columns are generally designed using the Priebe 1995 method. This determines you post stone column settlement. You can find it online. Essentially you work out an improvement factor n (generally around 2-3, lets assume 3)which is based on your area replacement, column friction angle, column modulus and the ratio of column modulus to existing soil modulus. Your original settlement (i.e. say 120mm without stone columns) is reduced by the factor n. Your post stone columns settlement is 120 / 3 = 40mm.

RE: Vibro Stone Columns

Thanks EireChch- I'd always been wary of the long-term performance in very soft clays...really appreciate your feedback.

Cheers,
Mike

RE: Vibro Stone Columns

Priebe's method is what I've seen being used in vibro stone columns projects here in Europe. I have never been involved in the final design of any of these projects as the contractors usually have their own in-house technical staff that develops their solutions, but some years ago I did a feasibility study and a couple of preliminary design calculations using Priebe's method for the foundation of large chemical tanks.

I programmed a simple spreadsheet as a study aid and the results were ok when compared with some design examples and software but it was never really tested with a real project. I enclose it to this post as it may help someone get into the method but please be aware that it may contain mistakes. Use it as you wish.

The original papers by Priebe are probably easy to find on Sci-hub.

RE: Vibro Stone Columns

(OP)
Thanks everyone for the great posts and links so far! asvcorreia: that's much more than a "simple" spreadsheet!

RE: Vibro Stone Columns

(OP)
In my market the typical application is in 10' to 20' surficial urban fill. It's a no-brainer when it's clean and relatively dense we have used area replacement ratio's as low as 12%. I get particularly uncomfortable with organics and peat layers. Any insights in adding grout or somehow sleeving (ie: geotextiles) in these conditions would be appreciated.

RE: Vibro Stone Columns

Geotextile encased stone columns can be used in peat / organics. I have not heard of adding ground combined with SC. That would be getting more into the CMC columns.

There is not much technical requirements when it comes to stone column design. The software that is used i.e. Kellers in house software is just the Preibe method. I have seen this a few times. You can do a stone column design on 1 A4 page with a hand calc.

The key thing is the onsite trials first to find your best grid layout then the verification with zone load tests, CPTs, plate load tests on top of columns. This is where the contractors practical experience is far superior to the consultants.

RE: Vibro Stone Columns

Use FHWA GRound improvement volume.

There are examples

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Resources

Research Report - How Engineers are Using Remote Access
Remote access enables engineers to work from anywhere provided they have an internet connection. We surveyed our audience of engineers, designers and product managers to learn how they use remote access within their organizations. We wanted to know which industries have adopted remote access, which software they are using, and what features matter most. Download Now
eBook - Managing the Context of Product Complexity Using the Digital Twin
Keeping track of changes to complex products is difficult—think Aerospace & Defense equipment, new generations of commercial aircraft, and software-based automobiles. A new way to managing the digital context of the physical product is required and the answer is the Digital Twin. This ebook explores the opportunity available for Operations and Maintenance for the Digital Twin. Download Now
White Paper - Trends in Industrial Filtration
Substantial progress has been made in filtration technologies in recent years. New filter media materials, designs and processes have led to filters that are more efficient, reliable, compact and longer lasting. This white paper will discuss the various trends that are impacting operational responsibilities of MROs today and the resources that are available for staying up-to-date on the latest filtration solutions. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close