Estimating relative density of gravels

State-of-the-art liquefaction assessment procedures largely evolved around clean sand as a reference soil type in the evaluation. As the density of the soil is a key factor influencing its liquefaction resistance, relative density has been implicitly used to estimate the density state of sands in the assessment. The relative density works well as a density measure for clean sands. However, the relative density concept is problematic when applied to fines-containing soils or gravel-sand-silt mixtures as standard laboratory procedures for evaluation of index void ratios (e_max and e_min) are not well established for such soils. This, of course, affects the evaluation of relativer density, as e_max and e_min are required to calculate the relative density of soil.

This project is a laboratory study in which methods for evaluation of e_max and e_min of gravelly soils that have been under development in the geotechnical laboratory at the University of Canterbury. The principal objective of this research is to further develop and standardize the laboratory procedures for evaluation of e_max and e_min of gravelly soils.

Collaborators:

• Professor Misko Cubrinovski, University of Canterbury

• Dr Sean Rees, Geotechnical Laboratory Research Engineer, University of Canterbury