Page 237 - Numerical Analysis and Modelling in Geomechanics

218 I.-M.LEE AND D.-H.KIM

Figure 7.11 Location of measurement points.

Table 7.4 Results of regression

Note
a Absolute displacement is the sum of the displacement occurring ahead of the tunnel face
and the displacement from regression analysis.
is assumed to be a unit matrix for the comparison of model I–1, model I–2 and
model II by the AIC (shown in Figure 7.14). It is found from Figure 7.14 that
model I–1 gives the maximum AIC among the three models, and model II also
looks small, even though slightly larger than model I–2.

Parameter estimation

Using the β values obtained in the previous stage, the optimized parameters are
obtained. As shown in Table 7.5, the objective functions of model I–2 and model
II are quite small compared with the function of model I–1.