Formulation of a three-dimensional distinct element model—Part I. A scheme to detect and represent contacts in a system composed of many polyhedral blocks

The distinct element method has advanced to a stage where the complex mechanical interactions of a discontinuous system can be modelled in three dimensions. An important component is the formulation of a robust and rapid technique to detect and categorize contacts between three-dimensional particles. The technique, described in Part I of this paper, can detect the contact between blocks of any arbitrary shape (convex or concave) and represent the geometrical and physical characteristics prescribed for the contact (e.g. three-dimensional rock joint behaviour). The method utilizes an efficient data structure which permits the rapid calculation on a personal computer of systems involving several hundred particles.