Risk and decision analysis for large underground projects, as applied to the Stockholm Ring Road tunnels

Large underground projects often include complex series of events and complex technical systems. The rock mass, for example, is very complex and associated with large uncertainties Consequently, decision problems within underground construction may be difficult to solve and wrong decisions may lead to unwanted risks. in order to facilitate decision-making, probabilistic decision and risk analysis can be used. This paper discusses a decision process useful for underground decision, problems and describes some available methods for decision and risk analysis. These methods have been applied to specific problems related to the Stockholm Ring Road project.