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.

We also offer a similar solution, but with a few different attributes to Grouted Rammed Aggregate Piers, called Precision Grouted Rammed Aggregate Piers. Precision grouted Rammed Aggregate Pier® (RAPs) Systems are used to target poor soil zones anywhere in the soil profile in order to increase pier capacities beyond what a regular RAP can achieve.  A specially equipped Geopier Impact mandrel is used in the installation and placed on the survey pin location with the stone valve in a closed position.  Pressurized grout is applied at the mandrel tip when the mandrel tip is at the correct elevation, where poorer soils are encountered at any level in the soil profile.  In all other aspects, precision grouted RAPs are the same as grouted RAPs.

GeoSolv’s Rigid Inclusion Systems always involve sizeable vertical crowd force, vertical ramming energy, and significant lateral stress increase. This action, along with the vertical ramming and heavy crowd pressure with lateral cavity expansion, is unique to GeoSolv and creates unsurpassed system performance.  These three factors are essential as they result in a more highly engineered system with improved performance over other rigid-inclusion approaches.

GeoSolv is here to find the right solution to your soil problem. Contact us for a free review of your project details and an obligation-free proposal or feasibility study.

Installation Methodology:

Geopier Grouted Rammed Aggregate Pier elements are built similarly to Geopier Impact with a grout mixture added to provide for high capacity Geopier elements in highly organic or very soft/loose soils. This system allows for standard spread footing and slab-on-grade design and provides for better capacity in poorer soils.

Treat up to 16m depths with 400-750mm diameter elements for high loads in loose sand, soft silt, and clay, fill, topsoils, and organics, with a combination of a grouted RAP element in the very poor zone below and a regular Rammed Aggregate Pier element above the poor zone.