In this chapter, we introduce a method of structuring all the ways in which rock mechanics parameters and variables can affect one another-the rock mechanics interactions. The method is presented within the wider context of an approach to integrate all the relevant information in rock engineering design and construction, rock engineering systems, Hudson (1992). The interaction matrix is explained first with examples and a general consideration of the nature of matrix symmetry. Then larger matrices are discussed demonstrating the links between rock mechanics and rock engineering, especially the pre-construction and post-construction interactions. Further example applications are given so that readers will feel confident in generating their own matrices for any problem. The RES approach aims to identify the parameters relevant to a problem, and their interactions, thus providing overall coherency in approaching rock mechanics and rock engineering problems.

Referring back to Fig. 1.12, the three-tier approach to all rock engineering problems, the inner ring represents the analysis of individual subjects. The chapters in this book have so far followed such single-subject themes but this chapter is about interactions and coupled mechanisms (represented by the middle ring of Fig. 1.12). It is only through the understanding of these interactions that we can arrive at the outer ring of Fig. 1.12 and the corresponding solution of complete rock engineering problems using theory and experience.

The need to study the interactions has always been present. Now we have much better computational capability and are being faced with increasingly large and complex problems in...