Session organizer, ASME/ASCE Joint Mechanics Conference (University of California, San Diego), 1989.
Organizing Committee, IUTAM, Symposium on Elastic Waves and Ultrasonic Nondestructive Evaluation, 1988-1989.
Session organizer, 7th ASCE Engineering Mechanics Conference (Virginia Tech.), 1988.
Session organizer, 6th ASCE Engineering Mechanics Conference (SUNY, Buffalo), 1987.
Advisory Board, International Conference on Fracture of Concrete and Rock, 1987.
Affiliate Member (Honorary), ASTM, Committee D-18, 1979-1989.
Session organizer, ASME/ASCE Joint Mechanics Conference (Univ. of New Mexico), 1985.
Session chairman, RILEM Symposium on Concrete under Multiaxial Conditions, Toulouse, France, 1984.
Session organizer, 5th ASCE Engineering Mechanics Conference (Univ. of Wyoming), 1984.
Session organizer, 4th ASCE Engineering Mechanics Conference (Purdue Univ.), 1983.
Session organizer, Int. Conference on Constitutive Laws for Engineering Materials, Tucson, Arizona, 1983.
Session chairman, Fourth Int. Conference on Numerical Methods in Geomechanics, Edmonton, Canada, 1982.
Secretary, International Committee for Numerical Methods in Geomechanics, 1976-1978.
Organizer, Workshop on Behavior of Concrete Dams and Mass Concrete under Multiaxial States of Stress, Central Board of Irrigation and Power, New Delhi, India, 1986-1987.
Editor (in-Chief), Journal of Engineering Mechanics, ASCE, 1994-2002. Acting Editor, 2004.
Editor, International Journal for Numerical and Analytical Methods in Geomechanics, (incorporating Mechanics of Cohesive-Frictional Materials), John Wiley & Sons, 2000 -present.
Editorial Board, ASTM Journal for Testing and Evaluation, 2006 -present.
Editorial Board, International Journal for Computational Civil and Structural Engineering, Begell House, Ltd., 2000 -2005.
Associate Editor, Journal of Aerospace Engineering, ASCE, 1998 -present.