Vibrocompaction is used to density loose sands and gravels by inserting the poker type vibrator into the ground with the aid of jetting water. A high degree of com­paction is achieved through vibration and displacement of the soil. Sand may be added from the surface to maintain site elevation.

Vibroreplacement makes use of the same vibrator, but crushed rock or gravel is used to backfill the hole to form a Stone Column or Aggregate Pier. In this applica­tion the stone columns are installed using a dry, bottom feed system, where the crushed rock is fed to the tip of the vibrator using an internal feed pipe and compressed air. Excellent densification of granular soils is achieved, while at the same time constructing a stone column (ag­gregate pier) that provides reinforcement and settlement reduction. Vibroreplacement stone columns are an ideal technique for mitigation of liquefaction because the system provides densification of liquefiable soils, reinforcement, and drainage.

Vibroreplacement stone columns are also used on clays and silts to increase bearing capacity and reduce static settlement. The system can also be applied in very soft clays with high loads by injecting cement grout with the crushed rock to form Cemented Stone Columns.

• Higher densification levels are achieved in granular soils relative to systems that use impact or vibratory hammers.
• Utilize clean, crushed rock with a high angle of internal friction, resulting in high capacity aggregate piers.
• Fast, economical system for mass ground improvement.
• Can be installed near existing structures.
• Progression of systems from Vibrocompaction to Vibroreplacement Stone Columns to Cemented Stone Columns.