Bender Element Measurement for Small-Strain Shear Modulus of Compacted Loess

Abstract

This study investigated the small-strain shear modulus behavior of compacted loess under isotropic consolidation. The small-strain shear modulus was obtained from bender element tests during the isotropic consolidation. The effects of excitation frequency, stress level, and stress history on small-strain shear modulus were analyzed. The test results suggested that the excitation frequency affects the measured values of shear wave velocity. An interval of wave path length-to-wavelength ratio was proposed to select the appropriate excitation frequency. Based on the test results, the effect of the stress level and stress history on the small-strain shear modulus of normally consolidated and overconsolidated soil was examined, whereby an empirical model was proposed to characterize the variation of small-strain shear modulus. The logarithmic law relationship mitigates the limitation in existing models that the power law relationship is incapable of accurately predicting the small-strain shear modulus for cases with large overconsolidation ratios. Finally, a framework was established to account for the effects of excitation frequency, stress level, and stress history on the small-strain shear modulus of compacted loess.