Liquefaction of silty geo-materials materials

Program Code: 
1631
Contact: 

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

 

Description of Work: 

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.