Many rock engineering projects today may face rock mechanics challenges such as (a) particularly complicated profile or excavation plan, (b) located near to existing infrastructure and thus pose a high risk to such structures, and (c) complicated geological conditions. In such situations, there may be no similar existing experience to lean on. Empirical methods have limitations and uncertainties in such cases. Therefore, SINTEF has developed a rock engineering tool to deal with the challenges. The tool is a combination of Investigation, Numerical modelling, and Monitoring. We use the term "SINTEF-TriPOD" for the methodology, and through projects it has proved to be a reliable tool. This paper presents the application of the SINTEF-TriPOD for two important infrastructure projects in Oslo, Norway, which are Follo Line metro project (4 billion USD) and a fresh water supply project (approximately 1.2 billion USD).
Many rock engineering projects today may face rock mechanics challenges such as (a) particularly complicated profile or excavation plan, (b) located near to and thus cause a high risk to existing structures, and (c) complicated geological conditions. In such situations, there may be no similar existing experience to lean on. Empirical methods have limitations and uncertainties in such cases. Therefore, SINTEF has developed a reliable rock engineering tool to deal with the challenges. The tool is a combination of Investigation, Numerical modelling, and Monitoring:
• Investigation: The investigation can be rock stress measurements before and during construction (hydraulic fracturing from rock surface, 2D and 3D over-coring), different geological surveys, drill holes, and geological engineering mappings to evaluate the rock mass quality. Obtained information is used for the second component of the "SINTEF-TriPOD" – numerical model.
• Numerical model: Establish a comprehensive numerical model, normally 3D numerical model is preferred as such model can handle complicated geometry and construction plans and methods. Simulations are to be carried out in certain order with clear objectives for each simulation steps. This is done to follow the planning and construction closely, helping the project team in making correct decisions.
• Monitoring: To improve the numerical model even further, stress and displacement are monitored continuously, and comparing them to the values from the numerical model. The model is calibrated, verified, and improved with the observations made in the surveillance program. This gives project team a reliable tool to help for decision making during implementation of the project.
