Description of field of research:

Mineral processing produces waste called tailings, mixtures of water and soil-sized particles. Tailings are usually stored on flat or gently sloping sites, contained by embankments made from soil or a coarse component of the tailings. Tailings storage facilities (TSFs) fail catastrophically following earthquakes or under static conditions far too often, resulting in tailings and/or their supporting embankment reducing in strength and, in some cases, turning to a fluid-like material (a phenomenon called liquefaction) that can spread many kilometres, destroying lives, property and the environment.

School

Civil and Environmental Engineering

Research areas

Soil Mechanics, Geotechnical Engineering

Depending on the students’ interests and skill sets, and the supervisors they work with most closely, the students' projects may involve experimental and/or theoretical work, based on UNSW’s Kensington campus.

It would be best for the student to work on this project after completing three years of the BE program after gaining a basic knowledge of soil mechanics.

The students will contribute to a larger research effort which has the objectives:

  1. identify the parameters and behaviour of tailings and supporting embankments when in varying states of saturation, when having a wide range of fines contents, and which have experienced varying amounts of particle dislocations due to aging, which control their susceptibility to earthquake induced liquefaction and strength post-earthquake; and
  2. develop relationships between the results of the cone penetration test (CPT) and the key parameters used to assess susceptibility to liquefaction and strength (including the cyclic resistance ratio and post-liquefaction shear strength).

Examples of 60-day student projects include:

  1. Assist with the generation of CPT results using UNSW’s calibration chamber and the development of correlations between CPT results and the tailings properties
  2. Use existing CPT results and their relationships to tailings properties to identify how well they can predict liquefaction susceptibility and post-liquefaction strength when the tailings is partially saturated, identifying flaws and aspects needing improvements
  3. Numerical modelling of tailings liquefaction, considering saturated and unsaturated states, when in physical models on an earthquake shaking table and/or in real TSF structures.