New Method for the Calibration of the Inertia of Resonant Column Devices

Resonant column devices are popularly used to evaluate the shear moduli and damping characteristics of soils at small strain amplitude. To use the resonant column technique it is necessary to accurately know the value of the rotational inertia of the top mass of the apparatus JAto evaluate shear modulus values derived from resonant frequency values. The paper describes a new and simple method for evaluating JAfor a resonant column device using two calibration rods of known geometry. The advantage of this calibration method is that a value of JAmay be determined without having to know the material properties of the calibration specimen. The paper describes the theory of the calibration technique and gives dimensions of typical calibration samples that can be used for resonant column studies. Typical measured calibration values are presented to show the accuracy of the calibration technique.