Aggregate piers are installed to reinforce fine grained soils using short, stiff aggregate elements.

Common Uses

  • Improve bearing capacity
  • Reduce settlement
  • Reduce liquefaction potential

Technical Details

Aggregate pier construction typically begins with a pre-drilled hole in soils where hole would remain open. In collapsible soils, a bottom feed vibrator can be used during construction. A standard crane of specially configured rig would advance the downhole vibrator to the target depth of the pier. Aggregate, which is typically new crushed stone or recycled concrete, is added via a loading chamber at the top of the vibro string and conveyed to the tip of the vibrator. The aggregate is compacted and densified in lifts by the vibrator. The high modulus aggregate pier installed during this process reinforces the treatment zone.