Micropiles

Micropiles are small diameter (generally less than 12”) drilled and grouted piles that typically utilize steel drill casing and/or a steel reinforcing core to transfer structural loads to a suitable soil or rock stratum.  They develop their axial capacity primarily through the bond between the grout body and soil or rock in the pile bonded zone, which allows them to provide both tension and compression resistance.

Micropile Installation

Micropiles are installed using much the same drilling and grouting equipment as is used for the installation of drilled and grouted ground anchors such as tiebacks or soil nails. Using this type of equipment allows micropiles to be installed in subsurface conditions where other conventional foundation systems may not be a reasonable alternative. The type of drilling equipment used to install micropiles allows for them to be easily socketed into hard rock and to penetrate through subsurface obstructions such as boulders or intermittent weak rock layers with negligible surface vibration. Compact, low headroom drills are available that can be used inside buildings or other limited space applications.

The Micropile Advantage

Because of their installation methods and structural characteristics, Micropiles offer numerous advantages that make them perfect solutions for a variety of geotechnical and construction challenges:

• High load capacity in both tension and compression
• Ability to install in difficult subsurface conditions or through modest obstructions
• Ability to install where elevated groundwater or caving soil conditions are present
• Ability to install in low headroom or limited access situations
• Ability to install where excess vibration is not desirable
• Tested to verify load carrying capacity

Micropile Applications

Due to the numerous advantages of micropiles, they are an economical solution for a wide range of applications.

Foundation Support for New Construction

Micropiles are the ideal solution for foundation support through difficult subsurface conditions, through subsurface obstructions or where vibration is a concern. Their ability to resist tension, compression and lateral loads makes them one of the most versatile foundation elements in existence.

Foundation Underpinning/Retrofit

Micropiles can easily be used to provide supplemental foundation support for existing structures. Their high capacity and ability to be installed in limited headroom or operating space makes them ideal for foundation underpinning or retrofit applications.

Slope Stabilization

Micropiles are an economical solution for improving the stability of slopes. They can be installed in a variety of challenging subsurface conditions and can provide improved resistance to driving forces resulting in greater factor of safety with minimal requirements for equipment access.

Earth Retention

Because they are able to resist both tension and compression loads, Micropiles can be used for earth retention applications where access and right of way are limited. Micropile earth retention systems are sometimes the only economical solution where there is a need to support adjacent existing structures and limited right of way makes anchoring a challenge for the resistance of lateral forces.