High-capacity, small-diameter, drilled deep foundation elements that are used to support new foundations or to underpin existing foundations.
Piling Systems Drilled Micropiles
Drilled Micropiles (DMPs or mini-piles) are high capacity, small diameter, drilled deep foundation elements that are used to support new foundations or to underpin existing foundations. Drilled Micropiles commonly consist of combinations of steel casing, threaded bar, and grout. Micropiles obtain their geotechnical capacity through side friction (also referred to as bond stress) between the grout and the surrounding soil or rock, and, in some cases, also end bearing. Drilled Micropile construction methods vary, depending on project-specific conditions, but are typically installed by advancing a grout-encased steel central bar with or without steel casing to a predetermined design depth using rotary-wash or compressed air drilling methods. Read More >>
Self-advancing micropile drill methods are also used, involving a hollow central bar, a sacrificial bit with ports, and an external full depth or partial depth casing as needed to control overburdened soils. In this case grout is pressurized down through the hollow bar, out the grout ports, and a pressure head is maintained so that the annulus in the soil around the bar is pressurized with grout. When full or partial depth casing is used, the frictional capacity must be adjusted. The casing in the upper sections of a micropile can also serve to increase lateral resistance and bending resistance for the micropile, and can assist with more versatile connections to structural components at or above grade.
Drilled Micropiles are particularly useful in limited-access situations adjacent to vibration-sensitive structures, and when penetration through relatively dense and/or obstruction-laden fill is required. In fact, drilled micropiles are one of the most effective techniques for penetrating obstructions.
- Working with Obstructed Soils
- Supporting Concentrated High-Weight Loads
- Sites That Require Low Noise/Vibration
- Working in Restricted Spaces
GeoSolv’s Piling Systems offer distinct advantages for various construction challenges compared to traditional methods such as driven piles (H Piles, Pipe Piles, Precast Concrete Piles), caissons (pier foundations, bored piles, drilled shaft piles), or continuous flight auger piles (CFAs, auger cast piles). To learn if one of GeoSolv’s Innovative Foundation Solutions is right for your project, contact us today for an obligation-free feasibility report or proposal. We are always happy to help you avoid the risks associated with poor soils and deep foundation systems.