Geotechnical Testing Systems All Products Resources

Resonant Column Torsional Shear Test System

What is the Resonant Column Torsional Shear test?

Resonant Column Data Sheet
Sample Geotechnical Report

LoadTrac II/FlowTrac II RC-TS

Geocomp's resonant column and torsional system is based on the Long-Tor Resonant Column Apparatus developed by Dr. Vincent P. Drnevich (patent 1974) at Purdue University. The LoadTrac II/FlowTrac II RC-TS system is a fully automated system designed to measure the shear modulus and damping of soils at strains down to 10-7. The unit completely automates saturation, consolidation, resonant column, torsional shear, and stress-path test phases. The system consists of a computer-controlled unit that utilizes an oscillator motor to apply cyclic torsional loading to the top of the specimen for a range of excitation levels. Unlike other systems, a direct torque measurement is made at the bottom of the specimen to completely eliminate issues of back emf. Resonant column and torsional shear testing can also be followed by a stress-path triaxial test. The system is capable of displaying the current status of a test and graphically portraying the progress of the test in real time.

Applicable Test Standards

  • ASTM D4015, D4767
  • AASHTO T 297


  • Option to perform torsional cyclic shear for studying cyclic strength and liquefaction
  • Option to independently measure low strain shear modulus and compression modulus with piezoelectric sensors
  • Option to measure post-liquefaction shear strength
  • Measures resonance frequency, damping ratio, and shear modulus in torsion
  • Fully-automated and unattended back-pressure saturation, consolidation, resonant column, torsional shear, and axial shear phases
  • Capable of performing
    • Torsional shear within a range of frequencies from 0.033 Hz up to 50 Hz with strain and up to 10 Hz
    • Strain/stress-controlled and earthquake motion or user-defined irregular loading/strain tests
    • Triaxial or stress path shear test after torsional shear or resonant column test
  • Integrated low-force (counter-balanced) lift mechanism for removing chamber
  • Complete protocol flexibility to intermix automated test phases
Request More Information Resonant Column Test Apparatus