Genesis of transitional behaviour in geomaterials: a review and gap analysis

Ahmad Mousa, Tarik A. Youssef

Research output: Journal PublicationReview articlepeer-review

3 Citations (Scopus)


There has been sporadic but increasing reporting regarding the intermediate character of natural geomaterials which neither conforms to the general behaviour of fine-grained (clay-like) nor coarse-grained (sand-like) soils. Nonetheless, geoscience considers such soils as non-textbook or challenging geomaterials. The literature attempts to identify and analyse a range of threshold manifestations of their behaviour (e.g. liquefaction). However, the physics behind their transient nature is not described in a generic manner. Transitional behaviour (TB) is observed more often in soils containing measurable amounts of silt-size particles. The complexity of their structure–greatly dependent on a number of interrelated micro and macro parameters–is believed to discourage generalisation of the behaviour. This review collates the factors potentially controlling the reported transient character. In order to illustrate a more holistic picture of transitional soils, the available characterisation findings are critically categorised based on purpose and/or testing technique. Collective understanding of transitional soils can ultimately provide a more confident prediction of their ramifications in a wide spectrum of applications. The present initiative is meant to attract attention to the need for multidisciplinary research on quantifying the controversial character of this class of geomaterials. It is also attempted to highlight relevant discrepancies and identify research gaps.

Original languageEnglish
Pages (from-to)298-324
Number of pages27
JournalGeomechanics and Geoengineering
Issue number4
Early online date18 Oct 2019
Publication statusPublished - 2021
Externally publishedYes


  • Transitional behaviour
  • discrepancies
  • gap analysis
  • micro and macro parameters
  • silt-size particles
  • soil structure

ASJC Scopus subject areas

  • Geotechnical Engineering and Engineering Geology


Dive into the research topics of 'Genesis of transitional behaviour in geomaterials: a review and gap analysis'. Together they form a unique fingerprint.

Cite this