Foundational Solutions With Aggregate Piers

Take advantage of aggregate piers to give your structure’s foundation a quick and reliable ground improvement solution

When compared to deep foundation systems, vibro stone columns like this can be installed much quicker. This advantage saves time on project deadlines and creates a more efficient worksite.

Aggregate Pier Foundation Systems

CNC Foundations provides custom foundational solutions for your property and budget. One of these solutions is the use of aggregate piers, which are also called vibro- or vibratory stone columns, vibro-piers, and VSCs.

Aggregate piers are stiff columns of stone aggregate that we inject into the ground. They reinforce soft soil conditions to make the ground strong enough to support multi-story buildings, large commercial or industrial facilities, warehouses, or liquid storage tanks, among other structures. Aggregate piers often work best with soils that contain soft clays, silts, or man-made fills.

Aggregate pier installation is a ground improvement technique that constructs dense columns of compacted stone. The columns are installed in groups in soft soil to increase bearing pressure and mitigate settlement under structural footings.

Ultimately, we install aggregate pier foundation systems to prepare your site’s soil type to support the structure you build.

Getting Started

Aggregate Piers are made by pre-drilling a hole into the soil of foundation, lifting the aggregates, and then tamping them into the hole. This lifting and tamping process is repeated until the void is filled with aggregate, and each additional ramming step creates a tighter, sturdier foundation.

Other aggregate piers can be installed in a few different ways. If we’re installing the piers in sturdy cohesive soils, we use a dry top-feed method. If the soil is fine and unstable, we use a dry bottom-feed method. If we’re working with fine, unstable soils below the water table, we install the aggregate piers with a wet top-feed method. We vary and customize our pier installation methods depending on the soil and foundation requirements.

Improving the Soil Matrix

Vibratory stone columns create the compacted fill by way of a vibratory probe either in a pre-drilled hole or with custom rigging. These columns are compacted aggregate that is installed through existing soils to improve the geotechnical properties of the overall soil matrix. They are installed using a specialized vibratory probe called a “vibroflot.” The different installations listed above (dry top-feed method, dry-bottom feed method, etc.) determine how we use the vibroflot to install the piers. In a dry top-feed installation, we use the vibroflot to displace soil to create a hole and dump the stone aggregate into the hole. For the dry bottom-feed method, we put the vibroflot deep in the hole and raise it upward. As the vibroflot rises, it drops the aggregate into place. With a wet top-feed method, we mount the vibroflot on a rig or hang it from a crane, and jet water from its tip to create the hole. Then we lower the vibroflot into the hole gradually while reducing the water’s jetting pressure. Vibroflots are suited for a variety of installation methods, and they improve soil conditions no matter which method we use.

Improve Your Civil Construction Project With Aggregate Piers

Reach out to us today to learn more about aggregate piers and select the right ground improvement options for your construction project.

Aggregate Piers’ Big-Picture Solutions

Before the development of aggregate piers, construction crews had to remove soft soil types and replace them with man-made fills to install shallow footings for structural foundations. If the ground still could not support shallow foundations, deep foundations immediately had to be used. This was a problem because deep foundations are much more expensive than shallow ones. Aggregate piers provide a cost-effective way to make shallow foundations possible without removing the existing soil from the construction site. These ground improvement innovations help create the applications and solutions listed below.


Aggregate Pier Projects Completed since 2010

Applications for Aggregate Piers

Vibratory aggregate columns have been used to increase bearing capacity, decrease settlement, and mitigate liquefaction potential for all types of planned structures, including industrial buildings, embankments, dams, agriculture structures, tanks, and towers. In terms of functionality, vibro-piers:

  • Amplify weight-bearing abilities:
    Vibro-piers are an excellent solution for soil and foundations that are uneven, unpredictable, or made up of layers of varying material.
  • Minimize settlement:
    As each pier is driven into the soil, loose granular particles are compressed, creating a more sound and compact foundation on which to build.
  • Deter liquefaction:
    As non-liquefiable structures in potentially liquefiable foundations, VSCs are extremely effective in mitigating potential damage from water pressure, seismic movement, and
    general stress.

Uses for Aggregate Piers

  • Strengthening foundations:
    Aggregate piers are a simple way to dramatically increase the strength and bearing pressure of site soils so that they can meet the requirements of the project.
  • Wall and embankment stabilization:
    Aggregate piers are often used in soft-, poor-, or mixed-soil environments to provide stabilization for large walls and embankments. The stress of the pillars being vibrated into the earth compacts the soil, making the ground stronger, increasing its weight-bearing capacity, and overall safety.
  • Agricultural, municipal, and manufacturing support:
    VSCs provide a solid, compressed foundation on which to build structures with heavy equipment and machinery.

Job Types and Special Aggregate Pier Design Considerations

Aggregate piers are extremely versatile in terms of project use. Whether they are leveraged to create a foundation on which to build or to fortify existing soil with unknown or mixed density, vibro-piers are an effective solution to create lasting strength. Regardless of slope or seismic activity, VSCs create foundations capable of accommodating extreme bearing pressure.

CNC Foundations Aggregate Piers Improve Your Project’s Site

If you need to improve the ground on your construction site, CNC Foundations has the solutions you’re looking for. We customize our aggregate pier installation services to suit your site’s soil conditions and provide a solid base for your project’s foundation.

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