The observational method was applied throughout the construction works to optimize the supports for two projects. For each project, geotechnical calculations were carried out to verify the stability of the walls, considering the different load cases. Several scenarios were envisaged, each corresponding to a type of support to apply. Then, as the work progressed, an in-situ analysis of the rock was carried out. Regular monitoring made it possible to classify the rock in one of the predefined cases at each stage. By making it possible to check the exact geological conditions of the rock as the work progressed, the application of the observational method made it possible to optimize the work and limit costs while guaranteeing completion deadlines.
Gruslin et al. (Thu,) studied this question.