An analysis of bedrock fracture networks based on outcrop data to establish a baseline discrete fracture network model – Åknes rock slope in western Norway

Abstract

The purpose of the thesis is to establish a baseline discrete fracture network model for the area leading up from the back scarp to Flosteinbba above the unstable rock slope at Åknes. The model is intended to identify the key fractures in the fracture network responsible for groundwater flow and instability. The data was generated during a field campaign in August 2018, doing outcrop mapping of fracture strike and dip and terminations. The mapping data was then analysed and organized according to fracture sets and fracture frequencies. This showed a connection between bedrock lithologies and the fracture sets. The data show that the fracture network consist of slope dipping exfoliation fractures and systematic steeply dipping fracture sets. The discrete fracture network modelling and field observations indicate that the interconnected fracture network allows for both sliding and groundwater flow along the exfoliation fractures.