Liquefaction of silty geo-materials materials

Program Code: 1631

Objectives:

Liquefaction in (loose near-saturated) granular material is confusing as it can be triggered by both rapid monotonic loading and/or cyclic loading. Furthermore most studies are based on either clean sand or sand with a small amount of fines. However, a silty soil can also liquefy. Both mine tailings and coal ash are silt that may be prone to liquefaction. The primary objectives of our research in this area are:

Advancing the modelling of the influence of fines on sandy soil by having a unifying framework for both static and cyclic liquefaction.

Understanding the liquefaction of silts, and hopeful extend our liquefaction theories for sandy soil to silty soil.

Understanding the effects of slight unsaturation on liquefaction behaviour.

The influence of the soil grains being crushable.

Description of Study:

We intend to take in 1 to 2 PhD candidates to conduct PhD research in this pioneering area.

The research approach is largely experimental and using our specially developed in-house triaxial stations that can perform both instability testing and impart cyclic stress pulses of varying (in a given test) waveform. One of such station also incorporates unsaturated soil testing technologies.

We intend to synthesise/ interpret the experimental findings within the critical soil mechanics framework, and hopefully developed constitutive modelling to characterise liquefaction behaviour.

For study on silty soil, we will be using actual coal ash from a particular ash disposal site. This also allows some insights into the effects of crushable grains, noting that some of the grains of coal ash are crushable glass particles.

Contact:

A/Prof Robert Lo r.lo@adfa.edu.au