Geopier compared
to driven piles
Optimizing Investments Below the Ground!
Geopier compared
to driven piles
Optimizing Investments Below the Ground!
Do you have heavy foundation loads?
Consider a conventional shallow foundation supported on Geopier Rammed Aggregate Piers (RAPs). RAPs provide high bearing capacity, tension resistance, increased strength and stiffness, and high lateral friction.
Geopier® Rammed Aggregate Piers vs. Piles
Compare |
Geopier® RAPs |
Piles |
| System Type | Geopier RAPs are an intermediate soil reinforcement system. RAP construction increases strength and stiffness or weak soil and fill. | Piles are a deep foundation system: friction and/or bearing |
| Common Materials | 1½ to 3 inch open-graded stone on bottom bulb and below water. Then ¾ to 1½ inch well-graded, Class 2 AB, stone above water. | Pre-stressed reinforced concrete, steel H-piles, steel pipes, and timber |
| Construction Procedure | Drill 30-inch dia shafts to remove compressible soil the ram crushed rock in thin lifts back to footing bottom. Vertical RAMMING Makes the Difference. | Mostly driven with diesel hammers, vibrated or screwed into ground. |
| Construction Scheduling | Performed during just after rough grading of building pad. Possible to work as part of grading permit. Install 30 to 60 RAPs per day resulting in significant time and cost savings. |
Usually performed 30 to 45 days after building permit, due to indicator piles and pile casting lead times. 12 to 24 per day. |
| Environmental Impact | Low, transient, high frequency, ground vibrations and safe near historic masonry buildings. Noise levels lower than 75 to 85 decibels at 50 feet. Use of recycled aggregate or recycled concrete adding to LEEDTM points. |
High, steady state, ground vibrations during installation leading to nearby building damage. Noise nuisance in urban communities, up to 110 decibels at 50 feet during driving. |
| Design settlement | Typically 1 inch or less. May be controlled to 1/2 inches or less upon request. | Typically 1 inch or less |
| Bearing capacity | Per RAP: Soft bay mud ~ 45 to 60 kips. Loose to medium dense silty or clayey sand ~ 75 to 110 kips. Medium stiff to stiff clay ~ 60 to 90 kips. All ASD values. |
Depends on soil conditions and type of pile; typically 20 to 50 tons per pile |
| Uplift capacity | Depends on soil conditions; typically 25 to 40 tons per RAP uplift element ASD. | Depends on soil conditions and type of pile; typically 20 to 50 tons per pile |
| Lateral capacity | Sliding friction on footing bottom. Typically f=0.5 ASD. Developed on footing bottom with friction and high stress concentration on rammed aggregate. | Developed in bending of the pile and confinement of the soil |
| Element "group" effect | Capacity per RAP element is increased when elements are in group because of the horizontal stress reflection. | Capacity per element is reduced for pile drag on matrix soil. |
| Verification test for design criteria | Full-scale Geopier Modulus Test. Cyclic uplift testing to 200% ASD capacities. | Full-scale pile load test |
| Installation in seismic areas | Eliminates or reduces need for horizontal tie-beams. | Requires tie-beams per IBC and CBC. |
With over 60 projects in Northern California and 1,000 across the US, Geopier Rammed Aggregate Piers have proven long term performance and excellent cost savings.
VERTICAL RAMMING MAKES THE DIFFERENCE!
Providing greater strength and stiffness!
685 PLACERVILLE DRIVE | PLACERVILLE CA 95667
(530) 621-4867 | (530) 621-4837 fax
© 2004 FARRELL DESIGN-BUILD COMPANIES, INC.
GEOPIER® is the registered trademark of Geopier Foundation Company, Inc. CHANCE® is the registered trademark of Hubbell Power Company Inc.
