JW Ridley was the first chair of the “New Zealand National Society for Soil Mechanics and Foundation Engineering” which later became NZGS. He was also the first recipient of the NZ Geomechanics Award, for which he gave a lecture on The Economics and Correct Use of Natural Materials.
The JW Ridley Geomechanics Paper Award is bestowed on the authors of papers that are distinguished in their contribution to the development of geotechnics in New Zealand. It is awarded every three years to the Society member or members producing the adjudged “best” published paper during the three year period. The winning paper is considered to be distinguished in its contribution to the development of geotechnics in New Zealand.
Six excellent papers were reviewed and evaluated by a panel of experts (Mick Pender, CY Chin & Kevin McManus), who unanimously agreed that the winner of the JW Ridley Geomechanics Paper award for 2018-2021 is Dr Mark Stringer for his paper “Separation of pumice from soil mixtures“, published in Soils and Foundations in August 2019.
The review panel made the following comments about the paper:
- The paper is about separating particles of different densities, a question that many people have asked. The investigation is well-executed, and the author appears to have developed a viable lab method and has done the investigation single-handed.
- This paper makes an important and practical contribution to geotechnical practice in NZ. The assessment of the properties and behaviours of pumice soils is very important and the ability to measure the proportion of pumice grains is a key step forward.
- The paper presents a novel method with the potential towards becoming an industry-standard.
Mark obtained his PhD from the University of Cambridge, following research on the axial load distributions on piled foundations in liquefiable soils using a geotechnical centrifuge. Since joining the department at the University of Canterbury, Mark has been involved in a series of element testing projects on New Zealand soils, including the silty soils around Christchurch and the pumice-rich deposits of the North Island. As a core part of this work, Mark has been trialing the use of the innovative gel-push samplers for sampling of pumice soils.
