Shear modulus and damping for three compacted clays at different consistencies from resonant column testing

Abstract

Compacted clays are used in the construction of embankments, dikes and as landfill sealing. Dynamic shear modulus and damping, dependent on the confining stress and shearing strain amplitude, are required in the seismic analysis of such geotechnical structures. A series of multi-stage tests in a conventional fixed-free resonant column device were conducted to determine these material properties for three medium to high plasticity kaolin clays. A compaction state corresponding to optimum water content at Proctor density was used as a reference. Water content was subsequently modified to reproduce a 3% drop in density. The associated three states were then tested to assess the effect of consistency on the dynamic soil properties. Particular attention was paid to the proper calibration of the device. Design equations are provided for use in practice.