The constitutive behaviour of granular soils under repeated dynamic loading

Within the frame of the FWO project G.0397.09 "The constitutive behaviour of granular soils under repeated dynamic loading", the Structural Mechanics Section of the Department of Civil Engineering of KU Leuven has a vacancy for a

PHD STUDENT (M/F)

The project is funded by the Research Foundation Flanders (FWO). Partners in the research consortium are the Structural Mechanics Section of KU Leuven, the Geotechnics Laboratory of Ghent University and the Department of Industrial Engineering Sciences of the Katholieke Hogeschool Brugge-Oostende (KHBO).

The aim of this project is to develop an advanced numerical method for the calculation of the dynamic behavior of granular soils under repeated small amplitude dynamic loading. This allows studying long term effects of vibrations on structures, as arising from road and railway traffic, construction and industrial activities. Whereas the soil behaves (almost) elastically on the short term, non-negligible plastic behavior is observed over a large number of load cycles. This phenomenon is referred to as strain accumulation, since plastic deformations accumulate in very small increments per load cycle.  

A phenomenological approach is commonly followed, where observations made in cyclic triaxial tests are cast into constitutive laws. Phenomenological models often only give satisfactory results for the range of stress paths for which they have been developed; models attempting to represent a wider range of phenomena must incorporate a large number of parameters. As an alternative to phenomenological models, a micro-mechanical approach to the analysis of granular soils can be followed. The incorporation of information at the particle scale only requires physical properties of particles and their interactions. This should result in a profound understanding of the underlying physical processes and a better prediction of the behavior of sands under repeated dynamic loading.  A homogenization approach is followed to tackle foundation settlement problems at the macro scale.

The development of these innovative constitutive models is supported by laboratory tests, focusing on both the micro and macro mechanical scales. For this purpose, a cyclic triaxial test where bender elements can be incorporated is available.

The Structural Mechanics Section of KU Leuven is looking for a young candidate with a Master of Science degree in Civil or Geotechnical Engineering that has a solid background in computational solid mechanics and is motivated to prepare a PhD in Engineering within a period of four years.

More details on the research activities of the Structural Mechanics Section can be found on bwk.kuleuven.be/bwm. More information on becoming a PhD student at KU Leuven can be found at www.kuleuven.be/phd and on the web site of Leuven Arenberg Doctoral School (set.kuleuven.be/phd). Depending on their background (MSc diploma, research experience), students may need to pass a pre-doctoral test before being allowed to the PhD programme. This pre-doctoral test may consist of passing exam for a limited number of courses or giving an oral presentation of the past research work.

Interested persons are invited to send their application file before 31 December 2011 to professor Geert Degrande or submit their application via the website of the Arenberg doctoral school (http://phd.kuleuven.be/set/voorstellen_departement?departement=50000536#detail). This package should include the following documents:

• Cover letter with a statement of purpose (motivation).
• Curriculum vitae, including relevant research experience, list of publications, study curriculum with rankings, proof of proficiency in English (Toefl or IELTS certificate), contact details of two reference persons.
• Copy of diplomas and transcript of records.

Professor Geert Degrande
Department of Civil Engineering
KU Leuven
Kasteelpark Arenberg 40
B-3001 Leuven
Belgium
Tel.: + 32 16 32 16 67
Fax: + 32 16 32 19 88
E-mail: geert.degrande@bwk.kuleuven.be