Recent content by Geocontractor

Being a geotechnical contractor, we see this situation quite often. A better solution to drilled shafts is micropiles. They are faster, and work very well in karst geology. Capacities up to 175 tons at costs of $75-$125 per lineal foot, including rock drilling.

We are working on the project where the contractor is attempting to install the auger cast pile test pile and is struggling. Today, the mix seemed to pump fine, but the grout set up very fast and the rebar only went down 2/3 of the full length. Can anyone help me help him with a suggested mix...

I believe that Hayward Baker is working on a project right now in New Mexico doing seep soil mixing. I would contact their Texas office and ask for information.

Considering a project where there will be a 55' deep excavation. The top 13' is fill material (125 pcf) that can be laid back at a 1.5:1 slope. The lower 42' will be a vertical face cut by blasting the rock and excavating in lifts. The general shape of the excavation is square. Recovery on...

A fairly new technology in the US is dry soil mixing or lime cement mixing. I believe that it originated in Sweden. Maybe a good option to mix the bad soil in place and create "better" soil.

grouterup, need to know water content of soil. dry soil mixing ususally works better with an adequate supply of ground water. I believe that the columns can begin to be formed at depth while the tool is pulled to the surface. Fairly new technology in the US so I am not too familiar.

If you go to http://www.haywardbaker.com/services/vibro_replacement.htm there is information regarding the installation of vibro-stone columns to mitigate liquifaction. If you register on the site, you can also download/view project summaries on projects completed with this technology. Hope...

BDBCRUZ, I have a link to a website for vibropiers/stone columns/whatever that have been used for liquifaction.

This may be old news, but have you considered jet grouting below the footing to increase the baering capacity of the soils? The soil sounds like it may be ideal for this type of work. I have done it in the kitchen of an operating hospital and it has worked well.

One other item, check the "Projects & Literature" tab on the Hayward Baker web page. There is a case history on a VCC project in NJ. Good Luck.

Evenbetter & Inaz: The concrete elements are created using the VCC (vibro-concrete column) method. Concrete columns are formed by inserting a vibratory "probe" into the ground through the soft materials, then forming a concrete column by pumping concrete through the vibratory probe while it is...

Have you considered combination method such as a vertical concrete element installed through the soft layers and a geogrid "mattress"? Has been used on several projects for NJ highway department.

We have pumped 1,000s of gallons of sodium silicate grout to stabilize running sands for subways, buildings, shafts, etc...Do you have more specific information?

Your methods are almost correct. There is also dry top feed. Why do you need wet feed? Yes it is possible to do wet bottom feed.

Does anyone know the basic design methodology for auger cast piles? Is it strictly an end bearing calculation, skin friction, or a combination of the two? To determine end bearing capacity, would you use the Neely formula of ultimate unit end bearing capacity = 1.9 N where N is SPT value of...