Directional properties of small strain shear stiffness in soils

Abstract

A compiled database of shear wave velocity measurements in a variety of clays, silts and sands shows directional hierarchies between downhole (V_sVH), standard crosshole (V_sHV), and rotary crosshole (V_sHH) tests. The special in situ database has been collected from 33 well-documented geotechnical test sites. Expressions relating the small-strain shear modulus in terms of effective confining stress level, stress history and void ratio are explored for each of these three modes of directional shear wave velocity. The relationships are separated initially into soil groups (intact clays, fissured clays, sands and silts), and then generalised to consider all soil types together.

Keywords:

• anisotropy
• modulus
• shear wave velocity
• shear modulus
• stiffness
• small-strains

Acknowledgments

The authors appreciate the support provided by the US Department of Energy (DOE) at the Savannah River Site (SRS) in Aiken, SC and ConTec Investigations of Richmond, BC and from Singapore Ministry of Education (MOE).