Geotechnical Testing: Tests & Capabilities
Our fully automated laboratory is equipped with two triaxial load frames with flow pumps where we can apply effective confining stresses up to 400 psi. We are capable of performing multi-stage, iso & anisotropic (kO) consolidation, triaxial extension tests, and we’re familiar with the SHANSEP method. We have 13 traditional 1-D consolidation frames and constant rate of strain consolidation capabilities. With our three direct shear boxes we can determine peak and residual strength for single and multi-stage specimens. We also have the ability to perform direct simple shear (DSS).
In addition to this we have 56 triaxial permeability chambers with permeameters for fastest turnaround time possible. TRI also has the ability to determine soil water characteristic curves for unsaturated soils. In addition to our advanced geotechnical testing capabilities we also have the ability to perform classification, granular permeability, Proctor and index density testing.
Shear Strength
RELEVANT STANDARDS | |
ASTM D2166 | Unconfined Compression |
ASTM D2850 | Unconsolidated Undrained (UU/Q) Triaxial Compression |
ASTM D3080 | Direct Shear of Soil |
ASTM D4767 | Consolidated Undrained (CU/R_bar) Triaxial Shear |
ASTM D6528 | Direct Simple Shear |
ASTM D7181 | Consolidated Drained (CD/S) Triaxial Shear with Volume Change |
TRI has the ability to extrude or remold soil samples for a large variety of diameters ranging from 1.4 to 6 in. (36 – 150 mm) to determine the shear strength of the material. TRI operates twenty 2000 lb (8.9 kN), two 5000 lb (22 kN), and one 40k lb (180 kN) fully automated load frames with ten flow pumps capable of applying effective stresses up to 500 psi (3,500 kPa) for performing a large variety of geotechnical shear strength testing. TRI maintains a direct simple shear apparatus and nine direct shear devices (2.5 in/63.5 mm diameter). In addition to isotropically and anisotropically consolidated triaxial compression/extension and, TRI also performs multi-stage triaxial testing.
Consolidation
RELEVANT STANDARDS | |
ASTM D2435 | Consolidation – Incremental 1-D |
ASTM D4186 | CRS Loading 1-D |
ASTM D4546 | 1-D Swell Potential |
ASTM D4829 | Expansion Index |
ASTM D5333 | Collapse Potential |
Triaxial | Ko Triaxial Consolidation |
TRI operates 12 fully automated 1-D consolidation frames that are capable performing custom loading schedules with loading pressures in excess of 64,000 psf (3,000 kPa). Our capabilities also include secondary compression (cα) analysis, constant rate of strain (CRS, three cells), swell potential, expansion index, and collapse potential analysis.
Hydraulic Conductivity
RELEVANT STANDARDS | |
ASTM D2434 | Hydraulic Conductivity of Granular Soils, Fixed Wall (diameter 2.5-7.0 in.) |
ASTM D5084 | Hydraulic Conductivity of Fine Grained Soils, Flexible Wall (diameter 1.4-6.0 in.) |
TRI has the capability to determine the permeability of soil and aggregates over a large range of velocities ranging from 1 x 10-11 cm/sec to 300 cm/sec. Field samples are extruded and mounted in the laboratory in one of our 55 triaxial permeability cells (Diameters 1.4 to 6 in., or 36 mm to 150 mm) with results often reported within 1-2 days depending on the sample’s initial saturation. For effective stresses less than approximately 5 psi (34 kPa) flow pumps are utilized to control the effective stress during backpressure ramping. For effective stresses greater than approximately 50 psi (340 kPa) and upwards of 400 psi (2,800 kPa) flow pumps are often utilized in concert with aluminum walled cells. The hydraulic conductivity of sand and gravel samples is measured in a variety of fixed wall cells utilizing manometers along the sample length to directly measure head losses. TRI is capable of testing up to approximately one-inch minus coarse grained material and is capable of applying confining loads during permeation.
Unsaturated Soil Mechanics
RELEVANT STANDARDS | |
ASTM D5298 | Soil Potential/Suction via Filter Paper |
ASTM D6836 | Unsaturated Soils – Soil Water Retention |
TRI performes unsaturated soil mechanics testing to support evapotranspirative cover systems, foundation design and field instrumentation and monitoring. TRI has the ability to determine the full soil water characteristic curve using a variety of methods that include hanging column, pressure plate, chilled mirror hygrometer, and humidity chamber. TRI can also perform column studies for multi-layered soil system interaction including capillary break evaluation. TRI has the capabilities to make laboratory measurements to support design of structures on expansive soils including TxDOT’s PVR methodology, PTI, and BRAB. We also have the ability to provide soil specific calibrations of suction-based and volumetric-based field instrumentation equipment for field deployment.
Rock Mechanics
TRI is capable of determining index and shear strength properties of rock interfaces and intact rock. Shear strength capabilities include testing of rock interfaces and intact rock in direct shear, unconfined, and triaxial stress states. TRI has the ability to impart a load of up to 100,000 lb (440 kN) in compression and in shear. TRI also performs testing for the evaluation of tunnel boring machine cutter wear and rock excavatability.
RELEVANT STANDARDS | |
ASTM D3967 | Indirect Tensile / Brazilian |
ASTM D4543 | Dimensional Tolerances for ASTM D7012 |
ASTM D4644 | Slake Durability |
ASTM D5084 | Hydraulic Conductivity of Rock Cores, Modified Method |
ASTM D5607 | Direct Shear of Natural or Saw-Cut Rock Interface |
ASTM D5731 | Point Load Strength Index |
ASTM D5873 | Rock Hardness by Schmidt/Rebound Hammer |
ASTM D7012 | Compressive Strength A – Undrained Triaxial Compression (ASTM D4543 Preparation) B – Undrained Triaxial Compression with Elastic Moduli C – Unconfined, Peak Load Only D – Unconfined, with Elastic Moduli |
ASTM D7625 | CHERCHAR Abrasivity |
Punch Indent | Punch Indentation/Penetration – Dollinger & Handewith 1998, Round & Conical |
Analytical Chemistry
TRI performs chemical analysis of soil samples for soil corrosion, thermal conductivity, and leachate analysis in support of geotechnical projects. TRI utilizes spectrographic methods and wet methods for analysis. TRI maintains laboratory grade equipment for testing and is capable of performing additional testing methods upon request.
RELEVANT STANDARDS | |
AASHTO T288 | Min. Electrical Resistivity |
AASHTO T290 | Water Soluble Sulfate |
AASHTO T291 | Water Soluble Chloride |
ASTM C289 | Potential Alkali-Silica Reactivity, Wet Chemical |
ASTM C837 | CEC of Clay – Methylene Blue Index |
ASTM C1580 | Water-Soluble Sulfates, Water Extraction |
ASTM D512 | Water-Soluble Chloride, Water Extraction |
ASTM D516 | Water-Soluble Sulfates, Water Extraction |
ASTM D1411 | Water Soluble Chloride Ion |
ASTM D4972 | pH of Soil |
ASTM D4978 | Screening of Reactive Sulfides in Waste |
ASTM D5334 | Thermal Soil Properties, Dry-Back Curve Testing |
ASTM D6276 | Soil-Cement/Lime Mixtures – Soil-Lime Proportion by pH |
ASTM G51 | pH of Soil, Corrosion Testing |
ASTM G57 | Electrical Resistivity |
ASTM G187 | Electrical Resistivity |
ASTM G200 | Oxidation-Reduction Potential (ORP) of Soil |
EPA 9045D | Analytical – Soil and Waste pH |
SM4500 | Sulfides, Methylene Blue |
Walkley Black | Soil Organic Matter (Oxidation Method) |
Index Properties
RELEVANT STANDARDS | |
ASTM C29 | Bulk Density and Voids in Aggregate, Rodded Unit Weight |
ASTM C88 | Particle Size – Soundness of Aggregates by Use of Sodium or Magnesium Sulfate |
ASTM C117 | Fines |
ASTM C127 | Lightweight Particles |
ASTM C123 | Relative Density (Specific Gravity) of Coarse Aggregate |
ASTM C136 | Particle Size of Fine and Coarse Aggregate |
ASTM C142 | Clay Lumps and Friable Particles |
ASTM C535 | LA Abrasion of Coarse Aggregate |
ASTM D422 | Particle Size Analysis |
ASTM D698 | Moisture Density – Standard Proctor |
ASTM D854 | Specific Gravity |
ASTM D1140 | Particle Size – Percent Finer than No. 200 |
ASTM D1557 | Moisture Density – Modified Proctor |
ASTM D1883 | CBR (California Bearing Ratio) |
ASTM D2216 | Moisture Density – Moisture Content |
ASTM D2419 | Sand Equivalent |
ASTM D2487 | Index Properties – USCS Classification |
ASTM D2488 | Visual Manual Classification |
ASTM D3042 | Carbonate Content of Aggregate – Fine Aggregate |
ASTM D4221 | Double Hydrometer |
ASTM D4253 | Maximum Index Density |
ASTM D4318 | Atterberg Limits (Method A – Multipoint) |
ASTM D4373 | Rapid Carbonate Content |
ASTM D4718 | Correction of Unit Weight and Water Content for Soils Containing Oversize Particles |
ASTM D4791 | Flat and Elongated Particles of Aggregate |
ASTM D4943 | Shrinkage Factors of Soils by Wax Method |
ASTM D5821 | Percentage of Fractured |
ASTM D6572 | Crumb Test for Clayey Soils |
ASTM D7263 | Moisture Content and Density (Unit Weight) |
ASTM D7626 | Loss on Ignition |
DOTD TR | Organic Matter in Soil Louisiana 413-10 |
USDA | Textural Soil Classification |
Specialty Testing
RELEVANT STANDARDS | |
ASTM D558 | Soil-Cement/Lime Mixtures – Moisture-Density of Soil-Cement Mixtures |
ASTM D559 | Soil-Cement/Lime Mixtures – Wetting and Drying Compacted Soil-Cement Mixtures |
ASTM D1429 | Specific Gravity of Water and Brine |
ASTM D1633 | Soil-Cement/Lime Mixtures – Compressive Strength of Soil-Cement Mixtures |
ASTM D4542 | Soluble Salt Content |
ASTM D4647 | Pin Hole Dispersion |
TEX-117-E | TxDOT Triaxial – Accelerated Method |
Viscosity | Couette Coaxial Cylinder |