FRACTURE SAMPLING ON A CYLINDER - FROM SCANLINES TO BOREHOLES AND TUNNELS

In this paper we develop correction factors for orientation bias when sampling rock fractures with a borehole. For a borehole with zero radi us we obtain Terzaghi's result for scanline sampling; otherwise the ap propriate correction factor may differ significantly from that obtaine d for the scanline model, depending on the relative size of the boreho le and the rock fracture. Two separate cases are discussed: the sampli ng of fractures with a borehole and sampling: with the surface of a bo rehole. Analytical expressions for the correction factors are graphed and tabulated.