Determination of stress magnitude and orientation plays a vital role in rock mechanics and the underground works industry. Local stress fields are disturbed during excavation and new induced stresses influence the surrounding rock mass. Information about their magnitude and orientation is crucial because in some cases the rock strength is exceeded, resulting in instabilities which can have undesired consequences. In turn, the stress state of the rock mass may vary with diverse locations because of factors such as regional tectonics, geology, and/or topography. A rule of thumb points out that on early stages the engineer should search for stress information on a radius of 50 km. Due to scarce and restricted information this is not always possible. For example, Norwegian hydropower depends on knowledge of local rock stresses in order to find the best location and design of solutions in the underground, and to minimize the need for steel lining in pressurized tunnels.
As part of the NoRSTRESS project, the authors have created a shallow 3D model of Norway where it is possible to extract a given area by centre and square side size on a 20 m resolution. This allows for fast and accurate creation of volumes and meshes for further numerical modelling on different scales. There is no evidence of such an effort in the literature for any other country. The results are expected to help evaluating stress magnitude and orientation on early project stages as well as to contribute to develop a 3D stress map of Norway. To have a better overview and understanding of the ground conditions to come will be useful, not only for the hydropower industry, but also for the emerging mining business.
KEYWORDS
parametric design; rock mechanics; numerical modelling; rock stress
