Questions 11.1 -1 1.1 0:
testing techniques
411.1 The section of site investigation borehole core shown in the
photograph is from a vertical borehole and contains three stress-induced
fractures. The top of the core is a stress fracture of the same kind. The
bottom end is a drilling break. Assuming that the strip of translucent
tape (adjacent to the numbers written on the core in the photograph) is
on the northern side of the core, in which horizontal directions do you
think the major and minor principal stresses act?