Conference History

The theme of the symposia entitled "Deformation Characteristics of Geomaterials" has a particular focus on the significance of small-strain stiffness of soils which is represented by Gmax (or G0). Over two decades of research in Europe and Asia have shown the fundamental importance of G0 as the initial starting point for all stress-strain-strength curves of soils and rocks.

The small-strain shear modulus can be measured by laboratory and/or in-situ field tests, primarily centered on the shear wave velocity (Vs). A variety of lab methods include: resonant column, torsional shear, bender elements, and local strain measurements in special triaxial apparatuses. For field determinations of Vs, there include a number of geophysical techniques including: crosshole, downhole, spectral analysis of surface waves, refraction, reflection, and suspension logging tools. The seismic cone penetrometer and seismic flat dilatometer are special direct-push technologies that are versions of the more traditional downhole test by cased boreholes. The value of Gmax applies strictly to the nondestructive range of strains (and stresses), generally < 10E-6 (decimal) and thus termed small-strain. At higher strains (and stresses), the appropriate moduli are generally less and a significant effort of research and investigation has centered around the modulus reduction curves from both experimental, numerical, and analytical formulations for use in constitutive soil models, finite element simulations, and practical problems.

The previous efforts of ISSMGE Technical Committee TC 29 have been a successful means to provide research level efforts and practical applications of Gmax to situations involving deformation evaluations in geoengineering. To date, we have had three Symposia, one Symposium in Print, and one special technical publication:

1. PreFailure Deformation of Geomaterials (1995), edited by Satoru Shibuya, Toshiyuki Mitachi, and Seiichi Miura, Volumes 1 and 2, Proceedings published by Balkema/Rotterdam; Event held in Sapporo, Japan from 12-14 September 1994.

2. PreFailure Deformation Behaviour of Geomaterials (1997), edited by Richard J. Jardine, M.C.R. Davies, David W. Hight, A.K.C. Smith, and S.E. Stallebrass, published as a part of Geotechnique by Thomas Telford, London.

3. PreFailure Deformation Characteristics of Geomaterials (1999), edited by Mike Jamiolkowski, Renato Lancellotta, and Diego LoPresti, Volumes 1 and 2, Proceedings published by Balkema, Rotterdam; Event held in Torino Italy from 28-30 September 1999.

4. Advanced Laboratory Stress-Strain Testing of Geomaterials (2001), edited by Fumio Tatsuoka, Satoru Shibuya, and R. Kuwano. Published by Swets & Zeitlinger, Lisse.

5. Deformation Characteristics of Geomaterials (2003). edited by Herve DiBenedetto, T. Doanh, H. Geoffroy, and C. Sauzeat, Volumes 1 and 2 (2005), Taylor & Francis Group, London; Event held in Lyon France 22-24 September 2003.

And so, towards continued success and progress in this field, the fourth Symposium on this most interesting topic is to be held from 22-24 September 2008 in Atlanta, Georgia.

Questions: webmaster@isatlanta2008.org