MICROPILES

Micropile Applications:

• Supporting New Loads in Congested Areas
• Seismic Retrofit
• Arresting Structural Settlement
• Resisting Uplift/Dynamic Loads
• Underpinning
• Excavation Support in Confined Areas
• Reticulated Pile Wall

Types of Micropiles

• Pushed or Driven
• Compaction Grouted
• Post Grouted
• Pressure Grouted

Important Micropile Parameters

• Soil characteristics at pile shaft/soil
• interface Rock at pile tip

Benefits of Micropiles

• High-performance
• Design loads from 3 to 100+ tons
• Can be readily designed for tension/uplift loads
• Appropriate for a wide range of ground conditions
• Suitable for low headroom and restricted access
• Low noise and vibration
• Can penetrate obstacles

Micropile Design Steps

• Geotechnical study
• Determine load to be supported
• Design pile-to-structure connection
• Design pile-to-soil or rock load transfer
• Develop a pile testing program

Micropile Quality Control

Test selected piles to two times the static design load using standard ASTMD113 pile load test criteria

Typical Micropile Programs Involve

• Drilling holes, 2 inch to 12 inch diameter
• The construction of a pile shaft consisting of structural steel pipes, grout, steel sections and/or placement of reinforcing steel, as required by design
• The filling of the hole with high-strength cement grout