Cased Micropiles

Cased micropiles are a relatively small diameter drilled or sometimes driven grouted pile with a steel casing or pipe as the primary reinforcement.  Diameters typically range from 4 to 12 inches with capacities up to 200 tons or higher.

While often socketed into rock to establish a bond zone for developing the pile’s capacity, some cased or pipe micro piles can develop their capacity through a soil bond or through end bearing.  A central reinforcing bar can also be utilized to provide tension capacities and a batter can be employed to help resist lateral forces.  A high strength neat cement grout is placed inside and along the outside of the casing utilizing pressure injection.

Construction of micropiles is versatile because of the wide range of drilling equipment and grouting techniques available. The compact size of the drilling equipment is of particular importance where piling is required in confined or low-headroom areas.

Technical Foundations can even utilize electric installation equipment where diesel exhaust cannot be tolerated.  Micropiles can be used for structural support in new construction as well as for underpinning existing foundations.

Benefits of Cased Micropiles:

  • Small installation equipment footprint.
  • Great for limited access applications.
  • Can be installed with electric equipment, eliminating exhaust issues with interior applications.
  • Can achieve relatively high capacities.
  • Ideal for certain soil conditions where buckling might be a concern with other piling solutions.

How it works:

  • The casing is rotated down to the design depth, adding additional flush thread casing sections along the way.
  • Once rock is encountered, the down-the-hole hammer is engaged to penetrate the rock and establish the bond zone.
  • The pile is then grouted as the casing is lifted then plunged back into the bond zone.
  • Central reinforcement, if required, is then installed.
  • The pile is cut off at the proper elevation and a pile termination plate is added or an underpinning bracket is installed and attached to the structure.

Technical Foundations has designed and installed cased micropiles from 3-1/2” driven pipe piles to 9-5/8” cased micropiles across the Mid-Atlantic region.

Celebrating Over 30 Years of Quality Foundation Construction Services

Serving Richmond, VA, Technical Foundations has over 30 years of industry experience. This gives you an edge on your project. All of our work is scoped to find the most cost-effective and productive methods to meet deadlines without sacrificing quality. Get in touch with us today to start your project the right way. 

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