A Modified approach for calculating dynamic shear modulus of stiff specimens by resonant column tests

1 Introduction Study of the shear modulus to represent the static and dynamic properties of geotechnical materials is a basic topic in the geotechnical engineering and many researchers (Hardin and Black, 1966; Zhang and Li, 2003; Richard and Richard, 1988; Yuan et al, 2000; Soo et al, 1995) have investigated this phenomenon. The resonant column device provides a powerful tool for testing the shear modulus and damping ratio of the soil-like materials. In 1984, the ?rst resonant column device…

A modified approach for calculating dynamic shear modulus of stiff specimens by resonant column tests

An error analysis of the dynamic shear modulus of stiff specimens from tests performed by a new resonant column device developed by the Institute of Engineering Mechanics, China was conducted. A modified approach for calculating the dynamic shear modulus of the stiff specimens is presented. The error formula of the tests was deduced and parameters that impact the accuracy of the test were identified. Using six steel specimens with known standard stiffness as a base, a revised dynamic shear modulus calculation for stiff specimens was formulated by comparing three of the models. The maximum error between the test results and the calculated results shown by curves from both the free-vibration and the resonant-vibration tests is less than 6%. The free-vibration and resonant-vibration tests for three types of stiff samples with a known modulus indicate that the maximum deviation between the actual and the tested value using the modified approach were less than 10%. As a result, the modified approach presented here is shown to be reliable and the new device can be used for testing dynamic shear modulus of any stiff materials at low shear strain levels