Soils Testing

Tests performed by the GeoSystems geotechnical laboratory include both standard and specialized procedures for determination of physical and engineering properties of soil and rock. All laboratory staff receive test performance training based on American Standards for Testing Materials (ASTM), U.S. Army Corps of Engineers, and GeoSystems' own in-house quality assurance standards. GeoSystems is approved by the U.S. Army Corps of Engineers.

Physical Properties:
ASTM D 2488   Visual Classification
ASTM D 2216   Water content
ASTM D 4318   Atterberg Limits
ASTM D 427     Shrinkage Limit
ASTM D 422     Particle Size by Wash Sieve/Hydrometer
ASTM D 1140   Percent of Passing #200 Sieve
ASTM D 4221   Dispersion Test (Double Hydrometer)
ASTM D 854     Specific Gravity
ASTM D 3042   Carbonate Content
ASTM D 4644   Slaking Durability

Consolidation:

GeoSystems tests undisturbed soil samples to provide data for estimation of foundation and embankment settlements. The laboratory can independently monitor back pressure, loading rate and permeability, and can apply consolidation pressures up to 100 tons per square foot (tsf).

ASTM D 2435  Conventional or rapid rate with optional back pressure.

Strength:

GeoSystems measures soil strengths through a variety of tests including unconfined compression, triaxial shear, direct shear and ring shear. The laboratory's triaxial testing equipment allows independent control and measurement of stress state, volume change, loading conditions and drainage conditions. In addition, GeoSystems uses laboratory vane, pocket penetrometer and Torvane tests to obtain site-dependent strength index correlations. Test include:

ASTM D 2166   Unconfined Compression of Soil
ASTM D 2938   Unconfined Compression on Rock Core
ASTM D 5321   Direct Shear
ASTM D 2850   Triaxial Compression - Unconsolidated-Undrained (UU)
ASTM D 4767   Triaxial Compression:

                         a) Consolidated-Isotropically sheared Undrained (CIU)
                         b) Consolidated-Isotropically sheared Drained (CID)
                         c) Multi-Stage UU
                         d) Multi-Stage CIU
ASTM D 2664   Triaxial Compression on Rock Samples
ASTM D 4648   Laboratory Vane Undisturbed or Remolded Strength
ASTM D 1883   California Bearing Ratio (CBR)

Permeability:

Permeability testing equipment provides both constant and falling head testing conditions. Routine application of high back pressure insures and maintains sample saturation. Gradients can be applied and controlled independently, and permeant can be changed without sample disruption. The lab's equipment is ideally suited for rapid turn-around of permeability test results on clay liners, with preliminary results in 24 hours. Tests include:

ASTM D 5084   Undisturbed Sample in Triaxial Cell
ASTM D 5084   Compacted Sample in Triaxial Cell
            -            Permeability consolidation in oedometer triaxial cell
ASTM D 2434   Permeability Test in Fixed Wall Permeameter
ASTM D 2434   Permeability Test in 12 inch Fixed Wall

GeoSystems uses a state-of-the-art "closed loop, constant volume, variable head" triaxial permeameter system. Triaxial permeameter testing is recommended by the New Jersey Department of Environmental Protection (NJDEP) and the U.S. Army Corps of Engineers (COE) for testing clay soils. When evaluating the permeability coefficient of drainage materials such as sands or gravel, the laboratory conducts tests in accordance with ASTM D 2434. GeoSystems designed its permeameters with over-sized ports and tubing to accommodate high permeant in-flow and out-flow and minimize hydraulic head losses. A "Mariotte tube" controls hydraulic gradient and maintains it to a minimum (usually less than 5) to reduce the migration of soil particles.