## 4 Analysis and Discussion
### Stability of Consolidating Slope  
Figure 10 illustrates the distribution of factor of safety along the slope (from the crest to the toe) for different values of mv and with the progression of infiltration. A close examination of the slope's stability indicates that the factor of safety tends to be less at both ends (crest and toe) compared to the middle of the slope for all values of mv. For an mv value of 0.2 kPa\({}^{-1}\), it is clearly seen that there is no difference in the factor of safety on the slope for all durations of rainfall. However, with an increase in soil compression, the factor of safety does appear to reduce with an increase in infiltration time across the different values of mv (from 0.02 to 0.000002 kPa\({}^{-1}\)). This difference is slightly more pronounced (especially for antecedent rainfall with duration from 7 days to 30 days) as the degree of soil compression increases from an \(m_{v}\) of 0.002 to 0.000002 kPa\({}^{-1}\). Overall, the slope tends to be generally stable (factor of safety greater than one). It could be concluded that the existence of suction in the unsaturated portion of the slope under the rainfall durations investigated has ensured this possibility. In order to confirm this claim, the stability of the slope is further examined with the rainfall intensity increased by an order of 10 (i.e., \(q/k_{s}=1\)) for a duration of 1 day to ensure full saturation. It could be observed from Figure 11 that for an m\({}_{v}\) value of 0.2 kPa\({}^{-1}\), the minimum global factor of safety of the slope (1.234) for a lower intensity of rainfall (i.e, \(q/k_{s}=0.1\)) is greater than the factor of safety for the slope subjected to higher intensity of rainfall (\(q/k_{s}=1\)), which is 0.861. A factor of safety less than unity as indicated for the slope under higher rainfall indicates critical slope condition with impending failure.  
Figure 10: \(Cont.\)It is crucial to emphasize that impending failure of the slope would be critical with continuous rainfall infiltration duration beyond 30 days for a highly compressible soil, as Figure 11 indicates.  
Figure 12 highlights the distribution of factor of safety with the duration of rainfall infiltration to buttress the points made above. As could be observed, for the slope with the least compressible soil, the factor of safety appears to remain constant for the entire duration of rainfall up to 30 days. The most drastic decrease in the factor of safety seem to occur with mv of soil beyond 0.02 kPa\({}^{-1}\). Although not obvious from the Figure 7 as seen previously, the effects of reducing the mv value of soil further from 0.0002 kPa\({}^{-1}\) seem to be less as the factor of safety of the slope only changes slightly for the entire duration of the rainfall (please see Figure 12).  
Figure 11: Minimum factor of safety on slope under different rainfall durations. **(a)** Minimum global factor of safety of the slope for intensity of rainfall (i.e, \(q/k_{s}=0.1\)). **(b)** Minimum global factor of safety of the slope for intensity of rainfall (i.e, \(q/k_{s}=1\)).  
Figure 10: Safety factors along slope for under different rainfall durations and \(m_{v}\) values, where (a) \(m_{v}=0.2\), (b) \(m_{v}=0.02\), (c) \(m_{v}=0.002\), (d) \(m_{v}=0.0002\), (e) \(m_{v}=0.00002\), (f) \(m_{v}=0.000002\).