Hydro-Mechanical Properties of an Unsaturated Frictional Material

8.2. SOIL-WATER CHARACTERISTIC CURVE MODEL 179
processes are shown in Figs. 8.8 and 8.9 for loose specimen. These figures depict the outcome
from the residual analysis for the three test phases used in building the 2D models. The plots
of observed versus residual values, observed versus predicted values are shown as well as the
normal probability plots and histograms.
- Plots of residual versus predicted variables and observed versus predicted variables:
50
40
Values 30
Observed
Plots of residual versus predicted variables and observed versus predicted variables are
given in Fig. 8.6 and 8.7 for drainage process (appropriate results from dense specimen
are given in Figs. E.6 and E.7 in Appendix E). The points in the plots of the observed
versus predicted values are close to the bisection line that indicates a small error in
observed and predicted values. The plots of the residuals versus predicted values do not
exhibit any systematic structure and thus indicate that the model fits the experimental
data well. Even the points are crowded in the saturated zone and residual zone the
range of residuals looks essentially constant across the levels of the predicted values.
Additionally it is stated here, that some discrepancies can be observed in Fig. E.7 (see
20
10
30 40 50 Predicted Values 0 20 10 0
60 70 80 90
50 of observations
Number
state column test I Loose specimen Initial void ratio = 0.89 1st drainage Transient
rate = 30 ml/min TDR/T 70 mm Flow
-0,6 -0,4 -0,2 0,0 0,2 0,4 0,6 0,8 Residual Values 0 10 20 30 40
-0,8
Residual Values
0,4 0,6 0,8
0,2
-0,6 -0,4 -0,2 0,0
-0,8
Predicted Values 30 40 50 20 10 0
-0,6 -0,4 -0,2 0,0 0,2 0,4 0,6 0,8 Residuals -4 -3 -2 -101234
Expected Normal Value
0.01 0.05 0.15 0.50 0.85 0.95 0.99
-0,8
Figure 8.6: Model validation results from 1 st drainage process (loose specimen, TDR/T70
mm)