Rigid Inclusions Grouted Rammed Aggregate Pier^® System

Grouted Rammed Aggregate Pier (RAP) systems are rigid inclusions designed to develop internal cohesion where standard RAP approaches do not yield enough overall capacity.  Typically grouted RAPs are used when encountering softer zones or organic zones in the lower reaches of the soil profile.   A Geopier Impact mandrel is used in the installation and placed on the survey pin location with the self-actuating stone valve in a closed position.  Grout is pumped into the mandrel prior to advancing the mandrel.  Grout levels are set to target a finished grouted pier elevation.  Stone is then placed in the hopper, and it mixes into the wet grout.  Once at design depth, the mandrel is raised, and a “lift” of stone-grout is extruded. At this point, the stone valve closes upon redriving to create a compaction front that forces the engineered material both downward and laterally. The raise-and-redrive process is repeated, and the grouted rammed aggregate pier is built up.   At the desired elevation, the grout is no longer present, and a simple, ungrouted rammed aggregate pier results in the upper reaches through the continuation of raising and redriving the valved mandrel into the ground surface. Read More >>