A Micropile is a 2 part system of a very high capacity steel member and grout. Once the system has been drilled and grouted, the micropile which is heavily reinforced now carries most of its loading on the high capacity steel member. The steel member diameter usually ranges from 2 to 10 inches.
Installed micropiles withstand compression, tension or uplift and lateral loadings and its generally load tested in accordance to ASTM D 1143 for compression, ASTM D 3689 for tension or uplift and ASTM D 3966 for lateral loadings.

There are four basic methods of installing micropiles:

  • Inserting the steel member after drilling and tremie or gravity grouting
  • Post grouting using multiple stage pvc exploders
  • Grouting during drilling using continuous threaded hollow-bar and a drill bit with grout holes.
  • Grouting through the casing


  • Micropiles can be installed in limited access and headroom conditions
  • Micropiles can be installed with minimum disturbance to adjacent structures with the appropriate installation methodology
  • Micropiles can be installed through existing foundations and are ideally suited to under-pinning and as load enhancement of existing foundations
  • Not required for pre-drilling
  • Due to the high capacity steel reinforcing elements, micropiles have high uplift load capacity and can be effectively used for tension structures
  • Due to the wide range of installation methods available and the relevant ease of penetrating boulders or hard rock formations, micropiles can be installed in difficult ground conditions.
  • Controls erosion

Where to use the System Micropile Applications?

  • Deep Foundation repair.
  • Structural underpinning
  • Foundation rehabilitation and repairs.
  • Stabilization of foundation on adjacent structure
  • Excavation support
  • Micropiles are used for the development of bridges, towers, and buildings.

What are the types of Micropiles?

    • Hollow Bar
      • Usually used for collapsible soils, it increases the bond stress of the soil.


  • Helical Pulldown
    • Usually used for deep foundations and with higher capacity structure load, used it friction and bearing to support structure’s foundation.Helical-Pulldown
    • Cased Micropiles
      • Stabilizes foundation of the structure combining the components of grout and casing.Cased-Micropiles
      • Uncased Micropiles
        • Stabilizes foundation of the structure combining the components of grout only.

Get in touch!

Contact the specialists at Geo Grout Ground Modification Specialist Inc. of Western United States for your jet-grouting project needs. Call us at (650) 241-2400 for complete information on our Micropiles services or email us at inquiries@gggms.com to discuss your Micropiles needs today
Shoring at California

Shoring Contractor

Shoring Services,

Jet Grouting

Jet Grouting

Ground Grout Modification,

Compaction Grouting

Permeation Grout Contractor

Ground Grout Modification,

Compaction- Grouting-San-francisco

Compaction Grouting Contractor

Ground Grout Modification,