Geopier Impact® Rammed Aggregate Pier® Elements
A DISPLACEMENT TECHNIQUE
Geopier® Rammed Aggregate Pier® Systems
Geopier Impact RAPs are ground improvement elements that reinforce unsuitable soils to provide an improved subgrade for traditional shallow footing and slab-on-grade support. Impact RAPs consist of stiff columns of rammed aggregate that are constructed with a patented displacement mandrel equipped with a beveled tamping foot. The mandrel and tamping foot apply direct vertical ramming energy to densely compact successive lifts of high quality crushed rock. The vertical ramming action also increases the lateral stress and improves the surrounding soils, resulting in high-stiffness engineered elements. The displacement mandrel generates little to no excess spoils and eliminates the need for casing or dewatering. This displacement construction method is particularly advantageous on sites with caving soils, contaminated soils, and/or shallow groundwater. Impact RAPs can also be grouted to provide enhanced stiffness through relatively soft soil layers (such as organics or soft clay). For these reasons, Impact RAPs are the most-used widely used Geopier ground improvement system in the Northeastern United States.
Geopier dX1® Rammed Aggregate Pier Elements
A DISPLACEMENT TECHNIQUE
Geopier dX1 RAPs are ground improvement elements that reinforce unsuitable soils to provide enhanced bearing capacity and settlement control for conventional shallow footing and slab-on-grade support. dX1 RAPs are constructed with a displacement method that utilizes a patented mandrel and compaction chamber, which makes them well suited for caving soils (such as sandy soils). They are installed with imported aggregate that is fed directly at the ground surface and without pre-augering, allowing us to install RAPs faster and more efficiently than ever before. As with our Impact RAP method described above, the aggregate is compacted in lifts using direct vertical ramming energy that results in high-stiffness engineered elements. After improvement, the subgrade is ready to receive traditional shallow footings and a slab-on-grade.
Geopier X1® Rammed Aggregate Pier Elements
A PRE-AUGERED “DRILL AND FILL” TECHNIQUE
As with our other Geopier RAP methods described above, X1 RAPs are ground improvement elements that reinforce unsuitable soils to provide improved bearing capacity and settlement control for traditional shallow footing and slab-on-grade support. They are constructed using the same patented mandrel and compaction chamber as dX1 RAPs, however X1 RAPs are constructed in a pre-augered hole and are well suited for non-caving soils (such as silty or clayey soils). As with our other RAP methods described above, the aggregate is compacted in lifts using direct vertical ramming energy that results in high-stiffness engineered elements. After improvement, the subgrade is ready to receive traditional shallow footings and a slab-on-grade.
Geopier GP3® Rammed Aggregate Pier® Elements
A PRE-AUGERED “DRILL AND FILL” TECHNIQUE
Geopier GP3 RAPs are ground improvement elements that reinforce unsuitable soils to provide an improved subgrade for traditional shallow footing and slab-on-grade support. GP3 RAPs consist of stiff columns of rammed aggregate and were the first type of Geopier elements to be installed in the Northeast. They are constructed using a “drill and fill” method, which consists of predrilling an augered cavity and filling it with successive lifts of high quality crushed rock. Each lift of aggregate is compacted with a patented beveled tamper that applies direct vertical ramming energy, resulting in high-stiffness engineered elements. The vertical ramming action also increases the lateral stress and improves the surrounding soils. Since GP3 RAPs are constructed with a predrilled “open-hole”, they are an effective solution for soils that are not subject to caving, such as clay. For soils that are subject to caving, Geopier Impact Rammed Aggregate Piers or Geopier GeoConcrete Columns may be more appropriate.
