Abstract: We combine the analytical solution of displacement for arbitrary-shaped tunnel in anisotropic media with the intelligent algorithm—differential evolution(DE) to investigate the displacement back analysis for horseshoe tunnel excavated on an anisotropic plane in transverse isotropic rock mass. The conclusions about parameter sensitivity, parameter unique identifiability and measuring line arrangement are obtained. In identifications, the high accuracy results for parameters can be obtained by DE algorithm. The parameter unique identifiability is not only related to the sensitivity, but also the combination type. When the vertical in-situ stress and the angle of isotropic plane are given, the maximum amount of uniquely identified parameter is 5. When the amount of identified parameter is equal to or bigger than 4, the combinations that cannot be uniquely identified will exist. When the amount of identified parameter is equal to or less than 3, any parameter combination can be uniquely identified with high accuracy.

Key words: transverse isotropy, displacement back analysis, differential evolution(DE), unique identifiability, horseshoe tunne