Experimental and Numerical Assessment og the Hydrogeological Behaviour of the Soil-Rock Interface

Abstract

Experimental and Numerical Assessment of the Hydrogeological Behaviour of the Soil-Rock Interface is written by Hallvard Haugen Nordbrøden. It is a master s thesis written at the Department of Geology and Mineral Resources Engineering at the Norwegian university of Science and Technology (NTNU) in Trondheim, Norway. It is written in cooperation with Norwegian Geotechnical Institute (NGI) in Oslo. In total there are 116 pages excluding appendixes.Constructing underground excavations may affect the groundwater balance in an area. The effects of this may influence on both tunnel stability and life time, and settlement on the surface.In geotechnical engineering, knowledge about water transportation is good. The mechanisms for water transport in soils are throughout described in numerous publications. For rock masses behaviour of water is more unpredictable because it follows fractures and weakness zones. There is little knowledge about the behaviour of the water transport over the interface between the two matters. This thesis is addressing these topics with special regard on the infiltration over the soil-rock interface.Slug tests in the field and a layered 1D model of soils in the laboratory are executed and simulated using the numerical software Seep/W from the GeoStudio suite. By the simulation of these cases, it is showed that continuous models can simulate water propagation between different materials.Large scale models with and without excavations are created with emphasis on realistic cases, different rock mass and tunnel depths. These are simulated and evaluated throughout.The findings are that this approach to estimate water flow over interfaces proves promising as the results from the large scale models are found realistic. By further evaluation of the found data and more investigations on the laboratory test, results the creation of new improved large scale models can be done. If based on and compared with results from previous real life cases it is thought that the models and methodology of this thesis is promising and a good approach.