Table 1: Summary of displacement experimental data: mean values and standard deviations of measured data.

Depth = 500 mm x y z Mean value [mm] 7.021 7.081 6.710 Standard deviation [mm] 0.007 0.009 0.134 Depth = 150 mm x y z Mean value [mm] 6.967 7.108 6.810 Standard deviation [mm] 0.001 0.001 0.007