About Geopiers

[Arcangelo]

Hi:

Just in general. What you guys think about Geopiers? And what you guys think about stone columns?

 

[bartshippee]

Both are excellent, relatively new technologies that offer potential solutions in certain applications that may be less expensive alternatives than more conventional solutions. Do your research and read up on case histories, etc. I've seen geopiers used successfully in a variety of conditions involving fairly thin (less than 12 feet) layers of poor overburden.

I also think the certified installer offers some sort of performance warranty on them.

 

[Geocontractor]

Stone columns installed by an experienced, reputable contractor with the latest equipment provide more quality control than a geopier installation. Specifically, the newer equipment provides computer print-outs immediatly after completing a column, which provides information such as volume of stone, energy to compact stone, depth, etc. All of which are important when analyzing an installation. Also, bottom feed stone column installation allows stone columns to be built at depths greater than geopiers, and at depths below the water table.

 

[GeotechGEinCA]

Computer QC is nice and easy. But Geopier installers log the soil excavated, and the aggregate lifts for every geopier installed on a site. In California, Geopier has gained wide acceptance in the building foundation market. More so than stone columns for 2 distinct reasons, 1) Geopier elements can resist much greater amounts of foundation stress due to higher stiffness than stone columns (5 to 25 times stiffer) and 2) Geopier elements can resist uplift forces caused by earthquakes or wind with a steel anchor cage. Stone columns are a good application for potentially liquefiable high groundwater clean sands.

Geopier is also quick and is relatively low cost when matched with a spread footing foundation. Geopiers have been successfully delivered on sites with soft clays to depths of 30 feet. Keep in mind, Geopiers are an intermediate foundation and oftentimes a good alternate to driven piles and concrete piers. We've used Geopiers for several multi-story building projects in California.