Constitutive Modelling of Granular Materials


Developments and Perspectives of Hypoplasticity

29 June to 3 July 1999 in HORTON, Greece.


The last of three Euroconferences devoted to granular materials and hypoplasticity, is intended not only to present to the scientific community the achievements and perspectives of this new theoretical frameworks, but also to be a forum for discussion on constitutive modelling.

After decades of research, the task of introducing a mathematical model describing the mechanical behaviour of plastically deformable media, especially granular materials and geomaterials, faces the following situation:

Several constitutive laws have been proposed but owing to their complexity, they are accessible only to a limited circle. The majority of the scientific community ignore them, and in many FEM software packages, some very simple, old-fashioned models are implemented. Researchers in the field of numerical applications are mainly concerned with techniques of regularization and consequently ignore the recent developments of constitutive modelling. As a result, the confidence of practitioners in the reliability of numerical modelling is reduced. Participants of the Euroconference in Horton are invited to discuss the State-of-the-Art of Constitutive Modelling of granular materials and geomaterials, to evaluate the present situation and identify needs for future modelling strategies.


The mechanical behaviour of granular materials and geomaterials arises in many areas, not only in civil engineering (geotechnics, tunnelling, coastal engineering, off-shore constructions) but also in petroleum engineering and mining as well as in the chemical industry (silos and transportation equipment).

In recent years a new constitutive model to describe the complex behaviour of granular materials has emerged, which has been termed “hypoplasticity”. Hypoplasticity is based on the principles of rational mechanics, and as a mathematical model presents a single tensorial equation, holding equally for loading and unloading. Its main advantages are that the parameters of the theory properly incorporate microstructural properties and prescription of a yield condition is unnecessary. Research has been carried out referring to experimental corroboration, finite-element applications, prediction of localisation, extensions for viscous and Cosserat materials, implications on controllability and stability of tests, cyclic phenomena, wave propagation and hidden relations to classical elastoplasticity.


  • Constitutive models of granular materials
  • Overall requirements
  • Evalutation
  • Necessity of higher order continua - general assessment
  • Macroscopic vs. microscopic approach
  • Impact on engineering practice
  • Incorporation of rate effects
  • The problem of calibration
  • Outline of modern developments
  • Teaching developments


Each participant is requested to pay in advance a fee of 150 Euro (approximately 300 DM, or 170 US$) to cover the cost of accommodation and conference expenses of all participants. In addition 50% of the speakers’ travel expenses will be covered. We also plan to provide some partial support of travel expenses to citizens of the EU not older than 35. The final figures for reimbursment depend on the final list of participants.


In order to guarantee a relaxed meeting with plenty of time for discussion, there will be only three speakers in the morning and three speakers in the afternoon sessions. Thus for the three days there will only be a total of 18 presentations. Note that one day is envisaged for a boat excursion so that participants have additional time for discussion. Please contact Prof. Kolymbas to propose the title and length of your paper. The proceedings will be published by Springer (cf. the proceedings of the previous workshop in Horton „Modern Approaches to Plasticity“, Elsevier 1993)



The workshop will take place in the small village Horton (near Argalasti) situated on the Bay of Volos.

Travelling by airplane

You can arrive at the international airports of Athens or Saloniki. Then take a public bus to Volos. From Volos take a taxi (or a local bus) to Horton (Athens - Horton: 357 km, Saloniki - Horton: 190 km). As an alternative, you can get by plane to the nearby island of Skiathos. The transfer from Skiathos to Horton by boat is very easy. For an interested party arrangements can be made for a bus transfer Athens - Horton.

Travelling by car

You can take the ferryboat from Ancona/Italy and get either to Igoumenitsa or to Patras. The routes to Horton are very picturesque.

Train connections from Athens to Volos

Departures at: 10:50, 15:30

travel duration: 5 hours

telephone railway station of Volos: +30-421-24 0 56

Bus connections from Athens to Volos

Departures at: 07:00, 09:00, 10:30, 12:00, 13:30, 15:00, 16:30, 18:00, 20:00

travel duration: 4,5 hours

telephone bus station of Volos: +30-421-33 2 53

ticket price: 5.100 drachmas

Bus connections from Thessaloniki to Volos

Departures at: 08:00, 10:00, 12:00, 15:30, 16:30, 20:00

travel duration: 3 hours

ticket price: 3.450 drachmas

Taxi service Volos

telephone : +30-421-52 2 22

This information should serve to orientation. Departure times and prices can be changed.


Participants wishing to add some days of vacation after the conference will easily find rooms. The prices for a double room (without breakfast) are ca. 25 to 40 US$ per day.


Click on the thumbnails to enlarge.

map near horton forest
map (430 kB) Near Horton (150 kB) Forest on Mount Pilion (139 kB)
pilion beach sunset
Horton (164 kB) Melani-Beach (near Horton) (82 kB) Sunset in Horton (103 kB)



caution 30. November 1998


Professor Dimitrios Kolymbas
Institute of Geotechnics and Tunnelling
Innsbruck University
Techniker Str. 13
A-6020 Innsbruck, AUSTRIA

fax: +43/512/507-2296