Presented by Dr Rolando Orense
Associate Professor, University of Auckland

Pumice-rich soils are often encountered in many engineering projects and their geotechnical characterisation is very important. Due to the highly crushable nature of the pumice sand components, the applicability of current empirical correlations which have been derived from hard-grained sands needs investigation.

The presentation focuses on the findings of the research projects conducted at the University of Auckland (with the support of EQC, NHRP and QuakeCoRE) to characterize the pumice sand properties and the dynamic and liquefaction characteristics of natural pumiceous deposits through field testing, high- quality soil sampling and laboratory testing. Moreover, the procedure developed to quantify the pumice contents of soil samples based on the crushability feature of the materials is presented.

Finally, based on the results obtained to date, an empirical chart correlating shear wave velocity and cyclic resistance as a function of the soil’s pumice contents is proposed.