Liquefaction Potential of Carbonate Sands

Liquefaction – the rapid transfer of soil interparticle stress onto pore fluid that leaves particles temporarily floating – can occur during rapid loading of sands, either cyclically (e.g. earthquake) or monotonically (e.g. during piledriving). Conventional understanding of liquefaction has developed through, predominantly, laboratory experimentation and physical modelling using silica sands (i.e. small rocks). However, during Dr Brennan’s recent post-earthquake reconnaissance visit to examine liquefaction in Indonesia, it was found that both silica and carbonate sands were present but liquefaction was only identified in silica sands. Carbonate sands, comprising crushed shells and bones etc., differ mechanically from silica sands in two ways (i) particles break at much lower stress levels (ii) particle shape.

Work by Dr Ciantia using discrete element modelling (DEM) has shown that allowing particles to break can cause the liquefaction threshold of a soil, previously treated as fixed, to move. The proposed project aims to use facilities at UoD, principally the cyclic simple shear, to experimentally verify this finding, evaluate the influence of both crushability and particle shape on liquefaction response, and hence verify and develop the DEM modelling.

The position is suited for a candidate with a good background in soil mechanics, evidenced by a good first degree in Civil Engineering. An aptitude for experimental soil testing would be an advantage, as would a working knowledge of dynamic soil behaviour.

Applicants wishing to apply should submit a one-page covering letter stating your background, academic qualifications, past research experience and interests, and future career aspirations. Please include a full CV, a copy of your academic transcript and the names and contact details of two referees to either [Email Address Removed] or [Email Address Removed]. Informal inquiries or queries can be sent to the same email addresses.