An analytical solution for recovering the complete in-situ stress tensor from Flat Jack tests

• A complete analytical solution is derived for obtaining the six components of the far field in-situ stress tensor.
• No assumptions need to be made with respect to the orientation of the initial far field stresses.
• The slots do not have to be perpendicular to the tunnel axis.
• The proposed analytical solution is not sensitive to Poisson's ratio for the rock mass near the tunnel.