A rectangular rosette strain gauge was installed on a smooth vertical wall at the end of an underground cavern. The installation was done in such way that one gage was horizontal, one at 45 degrees, and one vertical. Once the strain gages were installed, a blade saw was used to cut slots on 4 sides of that section to release the stresses. The elastic modulus and Poisson's ratio of the rock is estimated to be E=6.7 GPa, and v = 0.23 from other field measurements. The measured strain changes in the gages were recorded as follows: E0* = 8x10 45* = 11x10 and 90* = -15x104 a) Determine the magnitude and orientation of the principal strains. b) Calculate maximum principal stresses and maximum shear (Gmax, Omin, Txy) c) Build and draw Mohr Circle for the stresses and show/verify the results on the Mohr Circle. (890) y (845) 45 > (0) x