Technical Report NTB 81-12

Stripa ProjectPart I: Core-logs of borehole V 1 down to 505 m Geological SurveY of Sweden (SGU) Part ll: Measurement of triaxial rock stresses in borehole V 1

In the hydrogeological program of the Stripa project the vertical borehole V1 has been drilled 505.5 m. The drill core has been logged with regard to rock characteristic, fracture frequency, dipping and filling. The results presented as cumulative fracture diagram have formed the base for subdivision of the borehole according to fracture frequency. The variation in the fracture dipping was also taken into account. Chlorite is the most common of the infilling material in the fractures. fort he borehole 0 – 466 m the average fracture frequency is 1.46 fractures/m. Below 466 m the core is highly fractured and crushed indicating that the borehole has entered a crushed zone. Because of this the drilling is temporarily stopped.