Universal Soil Dynamics Testing System

Geotechnical Earthquake engineering design plays a crucial role in ensuring the safety and stability of infrastructure, buildings, and communities in seismic-prone areas. With the increasing frequency and magnitude of earthquakes, it is more important than ever to have advanced tools and systems to evaluate the seismic response of soil and rock formations. The GCTS SRC-100 Universal Soil Dynamics Testing System provides the ability to conduct advanced geotechnical earthquake engineering studies and assessments.

The SRC-100 system is a fully automated testing platform that can simulate the dynamic response of soil and rock formations to seismic loads, providing a realistic representation of in-situ soil behavior. The system can perform resonant column tests, cyclic/dynamic triaxial tests, ultrasonic velocities, and resilient modulus providing a comprehensive understanding of soil behavior under cyclic and seismic loading conditions.

The resonant column test is a widely recognized method for determining the fundamental dynamic properties of soil and rock formations, including the shear modulus and damping ratio. The dynamic triaxial test, on the other hand, provides a more advanced evaluation of soil behavior under axial and cyclic loading conditions, including the evaluation of strength, stiffness, and failure mechanisms.

The SRC-100 system is designed to perform high-precision, high-accuracy testing in accordance with the most recent international standards and guidelines. The system features advanced hardware and software components that allow for precise control of the test conditions, as well as real-time data acquisition and analysis. This ensures that the results obtained from the system are accurate and reliable, and can be used to make critical design decisions.

The GCTS Soil Resonant Column and Dynamic Soil Triaxial Testing System combine the features of both resonant column and torsional shear devices into one elegant system. This enables them to evaluate the effects of a number of soil parameters, such as void ratio, confining pressure, strain amplitude, number of load cycles on shear modulus, and material damping. By utilizing all available options, this system is capable of the full spectrum of modulus measurement, ranging from ultra-low strains to high strains with significant overlap.

For the resonant column test, a torsional drive is used to vibrate the top of the soil specimen at first-mode resonance at frequencies of up to 500 Hz while the bottom is fixed. A non-contacting rotational transducer is attached to the top platen to monitor the torsional motion directly. The non-contacting sensor is located on extended arms to amplify the rotational deformation and provides a shear strain resolution of 10-6. An optional accelerometer can also be installed to measure large shear strains. These systems can also perform closed-loop torsional shear tests (stress or strain controlled) on the same soil specimen, either statically or dynamically, at up to 50 Hz.

With these systems, soil specimens can be tested under isotropic (hydrostatic) or anisotropic conditions. The driving and measuring system are mounted on a “floating” frame, which allows large vertical specimen deformations throughout the complete test. Its unique configuration also allows for very large shear deformations of up to ±20°.

Relevant Standards

ASTM D4015 Standard Test Methods for Modulus and Damping of Soils by Fixed-Base Resonant Column Devices

ASTM D7608 Standard Test Method for Torsional Ring Shear Test

ASTM D2166 Standard Test Method for Unconfined Compressive Strength of Cohesive Soil

ASTM D2435/ D2435M-11 Standard Test Methods for One-Dimensional Consolidation Properties of Soils Using Incremental Loading

ASTM D2850 Standard Test Method for Unconsolidated-Undrained Triaxial Compression Test on Cohesive Soils

ASTM D3999 Standard Test Methods for the Determination of the Modulus and Damping Properties of Soils Using the Cyclic Triaxial Apparatus

ASTM D4186/ D4186M-12e1 Standard test Method for One-Dimensional Consolidation Properties of Saturated Cohesive Soils Using Controlled-Strain Loading (CRS Option)

ASTM D4219 Standard Test Method for Unconfined Compressive Strength Index of Chemical-Grouted Soils

 ASTM D4767 Standard Test Method for Consolidated Undrained Triaxial Compression Test for Cohesive Soils

ASTM D5084 Standard Test Methods for Measurement of Hydraulic Conductivity of Saturated Porous Materials Using a Flexible Wall Permeameter

ASTM D5102 Standard Test Method for Unconfined Compressive Strength of Compacted Soil-Lime Mixtures

ASTM D5202 Standard Test Method for Determining Triaxial Compression Creep Strength of Chemical Grouted Soils

ASTM D5311/D5311M-13 Standard Test Method for Load-Controlled Cyclic Triaxial Strength of Soil 

ASTM D5333 Standard Test Method for Measurement of Collapse Potential of Soils 

ASTM D7181 Method for Consolidated Drained Triaxial Compression Test for Soils

ASTM D2845 Standard Test Method for Laboratory Determination of Pulse Velocities and Ultrasonic Elastic Constants

AASHTO T307  Standard Method of Test for Determining the Resilient Modulus of Soils and Aggregate Materials