Quantitative models of bentonite mechanical evolution that are currently available are not fully able to represent all the complexities of the evolution of an emplaced bentonite in a repository context. A substantial effort is therefore needed of improve both the conceptual approaches and the numerical solutions in the current models. The updated/newly developed models need to be tested and verified using available data. There are some areas where fundamental data and the understanding of materials are incomplete; an efficient experimental programme is needed to support model development and testing (WP4).
A substantial database of knowledge on issues potentially relevant to bentonite mechanical evolution is available from earlier and ongoing laboratory and Underground Research Laboratory (URL) experiments, complemented in some cases by modelling studies. However, many such experiments / studies were not primarily focussed of the mechanical evolution of repository bentonite barrier material, and therefore a large part of the existing database needs to be re-evaluated to extract important information directly relevant to bentonite mechanical evolution, to compile the qualitative and quantitative observations and to develop the conceptual understanding. This will be done as a joint effort between WMOs, experimentalists and modellers, all with previous experience in the field, in this Beacon work package.
The key objective of Beacon WP2 is therefore to collect such relevant information as produced from past and ongoing projects that provide knowledge relevant to understanding bentonite mechanical evolution in a repository context, and to process it to a level where it can be useful as input to the other Beacon work packages.