Liquefaction of silty geo-materials materials
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.