Chair, External Examining Committee, Ph.D., Norwegian University of Science and Technology, Trondheim, Dr. Hans Peter Jostad, August, 1993.
Co-Chair, Organizing Committee, ASCE, “Space’92“, Third Int. Conference on Engineering, Construction, and Operations in Space, Denver, Colorado, 1992.
Chair, Organizing Committee, ASCE Geotechnical Engineering Congress, Boulder, Colorado, 1991.
Chair, USA Manuscript Review Committee, U.S. National Society of the Int. Soc. Soil Mech. and Geotech. Eng., U.S. paper contributions to XIVth Int. Conference on Soil Mechanics and Foundation Engineering, Hamburg, Germany, 1997.
Chair, Programs Committee, Engineering Mechanics Division, ASCE, 1991-1997.
Advisory Committee on Infrastructure Development, University of Puerto Rico, 1991-1993.
Computational Mechanics Committee, Engineering Mechanics Division, ASCE, 1987-1995, 1997 -present. Chair, 1988-1989.
Properties of Materials Committee, Engineering Mechanics Division, ASCE, 1983, 1991, 1992-2000, 2001 -present. Chair, 1989-1991.
Inelastic behavior Committee, Engineering Mechanics Division, ASCE, 1996 – present.
Session organizer, International Conference on Micromechanics of Quasi-brittle Materials, 1990.
Session organizer, Symposium on Advances and Trends in Computational Structural Mechanics and Fluid Dynamics, Washington, DC, 1988.
Committee on Computer Applications and Numerical Methods, Geotechnical Engineering Division, ASCE and GeoInstitute, 1984-1992, 1993-1999.
Chair and organizer, Mini-symposium, 12th U.S. National Congress of Theoretical and Applied Mechanics, Seattle, Washington, 1994.
Co-Chair, Conference on Nondestructive Evaluation of Civil Structures and Materials, Boulder, Colorado, 1992.
Organizing Committee, International Conference on Fracture Mechanics of Concrete Structures, Breckenridge, Colorado, 1992.
Advisory Board, Third International Conference on Constitutive Laws for Engineering Materials: Theory and Practice, Tucson, Arizona, 1990-1991.
Steering Committee, ASCE, Materials Engineering Congress, Denver, Colorado, 1990.
Organizing Committee, Conference on Nondestructive Evaluation of Civil Structures and Materials, 1990.
Session organizer, 9th ASCE Engineering Mechanics Conference (Texas A&M Univ.), 1992.
Session organizer, 8th ASCE Engineering Mechanics Conference (Ohio State Univ.), 1991.