Micropiles

Micropiles Fact Sheet:

Micropiles are small diameter drilled columns of steel and grout used to carry heavy loads when soil is weak or space is tight. Each pile is only 5 – 12 inches wide but can reach great depths and support hundreds of tons.

Where we use them

• • Strengthen old foundations that have settled.

  • Add extra support for new buildings on soft ground.

  • Tie back steep slopes or retaining walls.

  • Secure bridges, towers, and other hard‑to‑reach sites.

How micropiles are installed

• • Mobilize a Klemm or Hütte small‑diameter drill rig, adaptable for basements, slopes, or open sites depending on the project. 

  • Drill to design depth with rotary percussion, using casing or fluid flush in loose soils.

  • Lower a high‑strength steel bar or casing into the clean borehole.

  • Pump cement grout from the tip upward to bond the pile and expel debris.

  • Trim the pile head, allow grout to cure, and proof‑load selected piles for strength.

Advantages of Microiles

• High strength in a small footprint. One slim pile can resist large pushes, pulls, and sideways forces.

• Little disturbance. Drilling causes far less vibration than driving larger piles, protecting nearby structures.

• Works in tough ground. We can drill through rock, fill, and buried debris without stopping.

• Fast, flexible setup. Light rigs move in quickly, even under low ceilings or on narrow streets.

Together, these features make micropiles a reliable, low‑impact solution whenever solid support is needed in demanding conditions.

Micropiles: A Versatile, High Capacity Foundation Solution 

Micropiles are small-diameter, high-capacity, drilled and grouted deep foundation elements used for various construction applications, including underpinning, retrofitting, and new construction. Typically ranging from 5 to 12 inches in diameter, micropiles can be installed in difficult ground conditions, including in rock, through boulders, and in urban environments with limited access.

The installation process involves drilling a borehole, placing steel reinforcement, and grouting the borehole to form a composite structure capable of resisting high loads. Micropiles are versatile and can be used to support both compression and tension loads, making them an ideal solution for strengthening existing foundations, stabilizing slopes, and constructing new foundations in constrained sites. Their adaptability, minimal vibration, and ability to be installed with lightweight equipment contribute to their widespread use in geotechnical engineering

Benefits of Micropiles

Micropiles are small diameter piles that are installed by drilling, and can be used to reinforce existing foundations or construct new ones in challenging ground conditions. Benefits include:

• Versatility: Micropiles can be installed in a variety of soil types and environments, making them a flexible solution for many projects.
• Minimally Disruptive: Their small size and the drilling method used for installation means micropiles cause minimal disturbance to the surrounding area.
• Load Capacity: Despite their small size, micropiles can carry high load capacities, making them an effective solution for structural support.

Explore Completed Micropile Projects

Swipe through the projects below to learn more about our experience on a wide range of commercial, government and infrastructure projects utilizing micropiles. 

Choose an Experienced Micropile Contractor

Pacific Foundation is a highly experienced micropile contractor. We utilize micropiles extensively across a wide range of projects including spread footings, foundation elements,  bridge repairs, anchors, and more. One project that highlights their versatility is on the Oregon Capitol improvement project known as CAMS (Capitol Access, Maintenance and Safety). For more information, check out the CAMS III page here.

For the CAMS III scope, Pacific Foundation successfully installed 750 micropiles to underpin and stabilize the historic Capitol building as part of a comprehensive seismic retrofit and base isolation effort. This significant undertaking involved meticulous planning and precise execution, ensuring that the structural integrity and safety of the building were enhanced without compromising its historic value.

When and Why to Use Micropiles

Micropiles are a versatile solution, suitable for a wide range of applications. They are ideal for projects where access is limited, or where noise and vibration must be kept to a minimum. This can include urban environments, close to existing structures, or in environmentally sensitive areas.

If you’re embarking on a construction project that requires the reinforcement of existing foundations or the construction of new ones in challenging conditions, our Micropiles Services offer an efficient and effective solution.

Reach out to Pacific Foundation today to discuss how our Micropiles can meet the unique needs of your project.