The Society
Commissions and JTCs
ISRM Information
Products and Publications
List of Corporate Members
Links of Interest
Contact Us


Forgot your password?
Join the ISRM
Commission on Discontinuous Deformation Analysis - DDA


Prof. Yu-Yong Jiao


Prof. Gao-Feng Zhao



Ai-Qing Wu (China)
Anna Maria Ferrero (Italy)
Guangqi Chen (Japan)
Hong Zheng (China)
Jae-Joon Song (Korea)
Jia-He Lv (China)
Jian-Hong Wu (China)
M. Ronald Yeung (USA)
Nicholas Sitar (Canada)
Tomofumi Koyama (Japan)
Xiaoying Zhunag (China)
Yuan Wang (China)
Zhiye Zhao (Singapore)

Resat Ulusay (ex officio), ISRM President
Suseno Kramadibrata (ex officio), ISRM VP for Asia

Terms of Reference

Purpose of the Commission

  • to continuously promote block theory, Discontinuous Deformation Analysis (DDA) method and Numerical Manifold Method (NMM) research for diverse rock mechanics and engineering applications;
  • to consistently provide a forum for exchanging ideas and research outputs on DDA;
  • to effectively organize ICADD conferences, workshops and training courses;
  • to develop more systematic learning materials on DDA;
  • to stimulate research interests and attract young generations to further develop DDA and its derived methods;
  • to enhance international collaborations on DDA;
  • to publish text book/s, educational software  on the theory and application of Block Theory, DDA, and its derived methods;
  • to conduct more industry applications of DDA theory with a joint work force.


Products of the Commission

  • The 15th and 16th International Conference on Analysis of Discontinuous Deformation (Osaka 2020, TBD 2022);
  • Two Proceedings Books on Discontinuous Deformation Analysis of the above International Conferences;
  • Three DDA Workshops discussing the latest development of discrete numerical methods and their application in rock mechanics and rock engineering;
  • Two DDA training courses at ISRM NG’s academic and research institutions around the world to be instructed by Commission members. We continue to conduct 1-2 such courses per year in the third term of the commission;
  • Uploading “student versions” of basic DDA and other discontinuous analysis packages on ISRM website including: DDA and its derived methods. Basic versions of those computer programs will be downloadable for individual ISRM members along with a manual with some worked examples and benchmark tests;
  • One Special Issue in an International Journal on discontinuous analysis and/or manifold method.