Task 3 was defined not for modeling coupled THM processes of geological media, but as a forum of lectures and discussions on the state-of-the-art of rock fractures, their constitutive behavior and associated models, theoretical studies and experiments, advances and outstanding issues, and how this knowledge was used in performance and safety assessments for GDRW practice. The forum was conducted as a specific session at each Workshop, with invited internationally well-known scientists who had contributed greatly to the subject area’s scientific progress. All the lectures (see Table 3) and following discussions were greatly appreciated by both the funding organizations and research teams, and helped to broaden the view of the DECOVALEX project participants about the effects of the fractures and fracture systems on the performance and safety assessments of GDRW repositories and other geo-engineering and sciences.
| Name | Institution | Lecture title or subjects | Dates and locations |
| Prof. T. Esaki | Kyushu Univ., Fukuoka, Japan | Development of a shear-flow coupling test apparatus and some test results of rock joints | 8-10 May 1996, Tokyo, Japan |
| Prof. A. P. S. Selvadurai | McGill Univ., Montreal, Canada | Radial flow tests on intact and fractured granite cylinders subjected to thermal effects | Radial flow tests on intact and fractured granite cylinders subjected to thermal effects |
| Dr. A. Niemi | VTT, Finland | Studies on coupled hydromechanical effects in single fractures | |
| Prof. J. Gale | Memorial Univ., St. John’s, NF, Canada | Relationship between fracture pore structure, roughness, solute velocities and coupled stress-flow response models | |
| Dr. T. Chan | AECL, Canada | Modeling coupled hydromechanical effects of past and future glaciations | |
| Dr. Y. Tsang | LBNL, USA | The in-situ heater test at the Yucca Mountain site and T-M modeling | 9 December 1997, Berkeley, CA, USA |
| Prof. D. Pollard | Stanford Univ., CA, USA | Using analogs to understand coupled T-H-M-C processes in fractured and faulted rock masses: the role of structural geology | |
| Dr. C. Barton | UAGS, St. Petersburg, USA | Characterization of in-situ rock fracture systems using fractal and other techniques | |
| Prof. F. H. Cornet | I.P.G.P. Paris, France | Experimental investigations on hydromechanical coupling in fractured rock masses | 16 June 1998, Avignon, France |
| Prof. S. Gentier | BRG/DR/GIG, Orleans, France | Hydromechanical behavior of a natural fracture under normal and shear stresses | |
| Prof. M. Boulon | Univ., Joseph Fourier, Grenoble, France | Experimental investigations and hydro-mechanical modeling of natural joints | |
| Prof. A. Niemi | KTH, Stockholm, Sweden | Simulation of fluid flow in rock fractures | 24 May 1999, Kalmar, Sweden |
| Dr. N. Barton | NGI, Oslo, Norway | Mechanics of rock joints and discrete modeling for rock engineering | |
| Dr. F. Lanaro | KTH, Stockholm, Sweden | A random field model for roughness and aperture of rock joints |